Electronics Blog

Drill Press Controller Update Part 5

2026-03-30T19:22:00.002+08:00

Introduction
This post details the validation of the remaining hardware item on the drill press controller and Printed Circuit Board (PCB) updates.

Debug Validation
A series resistor was fitted between the microcontroller (PSoC) and the debug (TTL RX, TX) connector to serve as a basic type of input protection. During testing, the serial communications (USB to TTL converter) were intermittent, so the series 100 R resistor was reduced to 10 R to ensure reliable operation.

Updated Serial Input Resistors

PCB Update
As noted in the previous blog, the footprint of the input device (MAX22191) on the PCB required updating.

Updated Footprints on ESTOP PCB

During the PCB update, the top-layer silk screen text near the input and output connectors was increased to 1.5 mm.

Updated Text at Inputs on PCB

Updated Text at Outputs on PCB

To allow for easier hand soldering, a selection of component pads was increased.

ESTOP Mains Input Capacitor Pad Sizes

Updates were made to the power supply (AC-DC) and mains input capacitors.

ESTOP Mains Input Capacitor Pad Sizes Updated

The image below shows the updated board.

ESTOP PCB Update

Next, building the updated PCB, reviewing the mounting of the solid-state relay in the original enclosure shown below, and testing with the existing drill press setup.

Existing ESTOP Electrical on Drill Press

TDR Pulse Generator (Microchip) with Housing

2026-02-28T11:17:00.001+08:00

Introduction
This post continues a previous post that used a Microchip microcontroller and a buffer chip to generate a fast-rising edge. In this edition, the design is updated to suit an aluminium housing.

Assembled Pulse Generator Unit

Another Release
To cater to those requesting a USB-powered unit in a ready-made enclosure, the same Microchip microcontroller (ATmega16U2) and driver design from the previous blog were used. Some design changes were made to improve manufacturability, such as using a right-angle PCB-mount SMA connector.

For a small sample run of the new design, the rise time is comparable to the previous design, at 1.1 ns and faster than the original design at 658 ps.

Design Changes
The Microchip microcontroller (ATmega16U2) can be USB-powered (5 V) and operate at a logic voltage of 3.3 V. An external linear regulator was chosen instead of using the UCAP 3.3 V output supply from the ATmega, as the UCAP supply is intended for only low-current loads.

The self-powered connection example is shown in Section 20.3 USB Module Powering Options of the ATmega16U2 datasheet (doc7799.pdf).

ATmega16U2 Bus Powered Example (Courtesy Microchip)

With the power supply reduction to the ATmega I/O, the hex Schmitt-trigger power supply was also reduced to 3.3 V. The output performance was tested with Nexperia parts 74AHC04APW and 74LVC04APW.

To support DFM (Design for Manufacturing), the hand-soldered SMA connector from TE Connectivity (5-1814832-1) was replaced with a PCB-mount right-angle part from Molex (73391-0080).

Updated Pulse Generator PCB (2D)

Updated Pulse Generator PCB (3D)

Lastly, the board shape was resized to suit a metal case. A Hammond aluminium case (1455D602BK) was chosen for the PCB. This case was at the time less than USD 8 in quantities of 10 pieces and available at several online stores. A 3D-printed plastic case would also be an ideal, cost-effective alternative.

The plastic end caps supplied with the Hammond enclosure were replaced with PCBs. This change was aimed at a more turnkey solution, meaning the pulse generator PCB and end caps could come from the same PCB fabricator.

Pulse Generator PCB Assembly Modelled in Fusion 360

Designing the end caps was performed after the pulse generator PCB was completed, with some adjustments.

PCB End Cap (SMA End) in Fusion 360

PCB End Cap (USB End) in Fusion 360

After the pulse generator PCB was loaded into Fusion 360 and the end cap dimensioned, the PCB end caps were created in the PCB tool.

PCB End Cap (SMA End)

PCB End Cap (USB End)

Modelling in Fusion 360
The pulse generator PCB dimensions were chosen after making physical measurements of a Hammond aluminium case.

Pulse Generator PCB with Hammond Enclosure

Hammond provides a CAD file for the aluminium case; however, a physical measurement for the PCB width was performed because of the powder coating.

Assembly and Tests
The pulse generator PCB Rev 3 and end caps were sent for manufacture. For the 50 Ω controlled impedance on the pulse generator PCB, a predefined layer stackup was selected from the PCB manufacturer's options.

Pulse Generator Blank PCB

After assembling the pulse generator, programming and performing validation checks, the pulse generator PCA was slid into the Hammond case – almost. Checking another case, the PCA slid in very tightly. To make the PCA fit in all the aluminium cases, light sanding was required on the long edge of the PCB – tolerances and case anodising were possibly the culprit.

To fit the PCB end caps, the Hammond-supplied thread rolling steel screws #6 x 3/8" were changed to a set of salvaged pan head Philips screw. Using this type of screw is not ideal, and it should be replaced with a thread-cutting type to suit the C-shaped screw port in the Hammond case.

Pulse Generator SMA End View

Changing the straight SMA to a right-angle SMA connector had a negligible effect on the rising edge.

With a 74AHC04PW fitted, the rise time (20-80 %) was 1.18 ns. Using a 74LVC04PW, the rise time (20-80 %) was 759 ps.

Pulse Generator Output Rise Time (74AHC04)

Pulse Generator Output Rise Time (74LVC04)

Summary and Future Updates
As noted by readers, this design is slower than other designs offered on the market. However, as readers continue to use this design, write their own USB interfaces and highlight the need for faster solutions, new posts on this subject will be made available.

Engineering Files
The same Atmel Studio project applies to this project. Below is the updated revision 4 schematic, PCB Gerbers and PCB BOM for download. The Rev 4 includes only a minor top-layer change near the SMA connector.

In addition to the PCBs, the Hammond case 1455D602BK and suitable screws are required, for example, M3 x 8 mm thread cutting.

Pulse Generator Microchip Studio Project


Pulse Generator Schematic Rev4

Pulse Generator PCB Gerbers Rev4

Pulse Generator End Cap 1 PCB Gerbers Rev4

Pulse Generator End Cap 2 PCB Gerbers Rev4

Pulse Generator Bill of Materials Rev4

Model Rocket Engine Test Stands

2026-01-31T15:16:00.003+08:00

Introduction
This blog provides ideas and an example for 3D-printed metal rocket test stands designed to accommodate the popular Estes-sized model rocket engines.

Rocket Engine Holders

Why an Engine Test Stand?
To conduct rocket engine tests and measurements, a model rocket engine test stand was required. The stand was designed to serve as a motor anchor and mount on the horizontal axis. Since pricing from 3D metal printing companies has become more cost-effective, two stand designs were tried. Cost-reducing changes were implemented in the first revision test stands with a focus on reducing the printed weight.

Development and Manufacture
Autodesk’s tool, Fusion 360, was used in the development of the rocket engine holders. JLC3DP performed the 3D printing in stainless steel (BJ-316L).

What Changes?
Since 3D printing can be charged by weight (or volume), and because the thrust axis of the rocket engine is well established, the side walls of the rocket engine stand were partially excluded. The exclusion (cutout) in the stand body, as depicted in the images below, reduced the weight by approximately half. Additional changes could be made to reduce the weight if the focus were on cost-effectiveness, and with that in mind, the CAD files are provided at the end of this post for download.

3D Printed Test Stand
The first test stand was a simple prototype for Estes A-C engines. Some engines did not fit entirely into the 3D-printed metal holder, while others were easily inserted. This was because there are variations in the diameter of rocket engines, and older engines may have expanded with age.

Model of Model Rocket D Engine Holder

Model of Model Rocket C Engine Holder

Some videos below show how the motor was mounted. As a side note, the exhaust temperature was measured at almost 600 C, 100 mm from the engine nozzle.

Downloads
Files are exported from Fusion 360.

Fusion 360 C Engine Holder Model

C Engine STL File

The D engine holder model below has a 0.5 mm larger bore than the model in the above videos.

Fusion 360 D Engine Holder Model

D Engine STL File

Drill Press Controller Update Part 4

2025-12-16T02:32:00.001+08:00

Introduction
This blog details the fitting of the drill press controller's input circuitry and simple validation testing of the updated input circuitry.

Input Device Validation
In the earlier drill press post describing updates to the controller, the input circuitry (24 V) was changed from using discrete components to the PLC (Programmable Logic Controller) input device, the MAX22191, from Analog Devices.

The PLC input devices were soldered to the prototype board along with the input connector. It should be noted that the footprint for the MAX22191 on the board was found to be incorrect; however, testing was still possible.

Controller and Sensor Test Setup

The output of a power supply was connected to one of the PLC inputs, and the ON/OFF thresholds were measured by varying the voltage to the MAX22191 in 100 mV increments. The approximate threshold voltages were measured for an ON at 8.9 V, and the OFF voltage was 7.8 V. These voltages fall within the range specified by the ‘IN Voltage Upper Threshold’ and ‘IN Voltage Lower Threshold’ as stated in the MAX22191 datasheet.

Connecting a Proximity Sensor
The drill press controller utilises a proximity sensor to detect the spindle speed, with the output signal from the sensor resembling a square wave. The proximity sensor was connected to one of the MAX22191 inputs for testing. The output of the MAX22191 connects directly to the microcontroller (PSoC), so a pass-through connection was made in the PSoC for testing purposes. Using the PSoC fabric, the sensor input was routed to a test pin, which had a test pad.

PSoC Creator Spindle Pass-Through Connection

Shown below is a pulse from a magnetic sensor and the PSoC test pin, as measured by an oscilloscope. Oscilloscope channel 1 represents the input to the MAX22191, and channel 2 represents the PSoC test pin output. Upon reviewing the input and output signals, there is little difference in the timing of the signals, which is ideal for ensuring no change to the spindle
speed measurement.

Sensor Test Pulse Measurement

As an additional check, the delay from the proximity sensor to the rising edge of the output signal was also captured, as shown in the image below.

Sensor Test Pulse Rising Edge Measurement

In the next post, the final check will be performed on the debug channel, which is a TTL signal, and the circuit board will be updated with any changes.

WS2812 PSoC5 Creator Project

2025-11-11T20:00:00.001+08:00

Introduction
This short blog continues a previous post about a WS2812 addressable LED for an Infineon (Cypress) PSoC 4 microcontroller. This blog focuses on the project for the PSoC 5 with testing performed on a CY8CKIT-059 development board.

Rebuilding the Project
The PSoC5 project, ‘ws2812_test’, was downloaded from a post on the Infineon Community site.

Upon opening the PSoC5 project, the same issue noted in the previous blog with the PSoC4 was observed. The missing component is evident in the top-level design of the PSoC project.

Missing Components in PSoC Top Design

Unlike the previous post, where the WS2812 library was not included in the compressed project, the WS2812 library is included in the compressed project.

WS281xLib in PSoC Project Folder

The issue with the missing component was resolved by updating the project Dependencies in PSoC Creator.

PSoC Creator Dependencies - StripLightLib Error

The dependency for the existing WS2812 library was deleted. Next, the dependency for WS281xLib was added again to the project. The WS2812 folder in the local ws2812_test project was chosen.

PSoC Creator Dependencies - WS281xLib

After exiting the project Dependencies window, the Top Design sheet in the project displays the previously missing WS2812 component.

Updated Components in PSoC Top Design

Before rebuilding the project, a resistive pull-up was added to the SW button to suit a PSoC development board.

Switch Input Pin Configured with Resistive Pull-Up

The CY8CKIT-059 development board does not appear to have a resistive pull-up connected to the pushbutton switch ‘SW’ on the development board.

CY8CKIT-059 User Push Button Connection

This information is noted in Section 3.1 Theory of Operation, in the User Manual. With the default code implementation, the WS2812 will be driven by the development board as soon as the board is powered via the USB KitProg or PSoC connector.

Note from CY8CKIT-059 User Manual

Testing
A WS2812 module with eight LEDs was tested using the CY8CKIT-059 development board. The default code is configured for a single LED in blue, as shown below.

A modification is shown below for festive celebrations!

The LED colours for the above example were extracted from Line 117 in the PSoC project StripLights.c file. Setting of the two LED colours used with the Modulo operator, as shown below in main.c

Updated Code in Main.c from Line 54

Downloads
Linked below is an updated release of the PSoC project with the corrected dependencies to suit the CY8CKIT-059.

Updated Original PSoC5 Application - WS2812_test

PSU Characterisation with Rigol Equipment using SCPI

2025-10-27T19:59:00.000+08:00

Introduction
This brief blog provides a hobbyist solution for characterising the performance of devices such as DC supply modules using measurements from SCPI-capable test equipment.

Set up for Power Supply Test Fixture

Datasheets and Measurements
In most cases, the datasheet for a piece of hardware, be it a component or a printed circuit assembly (PCA), will provide sufficient information. For other cases, the performance or characterisation of the hardware requires a specific test or behaviour to be verified or quantified.

DC Supply Module Test (Example)
In this blog, the power-up voltage of an off-the-shelf power supply module was logged for different temperatures. The Device Under Test (DUT) was the STS1024S05 from XP Power.

A small test fixture was created to test multiple XP Power modules. In this example blog, the schematic shows connections to the supply.

Schematic for Test Fixture

The test fixture used pogo pins to connect to the castellated power module pads and banana sockets to interface with the test equipment.

Assembled Test Fixture with Device Under Test (DUT)

Test Software
The project's test software was originally started with Lab Windows. However, with many PyVISA Python examples available, Python in VS Code was selected instead. A Python script from Core Electronics was almost identical to the script required test setup, so the script was modified for this example. All credits to the team at Core Electronics for the original Python script.

Changes were made to the original script to suit the test setup. In the updated script, the test equipment type, the voltage step size of 100 mV, and the reported and logged voltages were updated as published here.

Measurements
The temperature was verified with a PC210 thermal camera for the duration of the measurement. The temperature variation was around 5 °C, which was attributed to the heating and cooling equipment.

A full listing of the measurements is available in a combined Excel file here.

Plotted below are measurements for the voltage range between DC 5.0 V and 6.0 V, where the DUT output was activated. The plot indicates differences in the DUT turn-on voltage for the temperature range sampled.

Measurement Results with STS1024S05

Drill Press Controller Update Part 3

2025-10-05T08:26:00.000+08:00

Introduction
This blog details retesting the drill press controllers' DC-DC power supply, fitting components related to the outputs and testing the output drivers.

Retesting the Power Supply
The original inductor fitted to the PCB (Printed Circuit Board) was removed and replaced with a 10 μH inductor. Testing the supply with the same load as the last post, the regulation at 165 mA and 330 mA was better than 0.1 %. The unloaded voltage was measured at 3.36 V, which is within component tolerances.

A short regulation test was made on the output of the AC-DC bricks after fitting the necessary parts to the PCB. The bricks output was as expected in tolerance.

PCB Setup for Power Supply Testing

Fitting Output Connected Microcontroller
The microcontroller and associated output hardware were fitted to the PCB, after which tests were performed. For the relay outputs, the output driver VND5160J was fitted to the PCB and then load tested. Separate FDN337N devices control the emergency stop and status LEDs, which were also checked.

Solid State Relay (SSR) Outputs
Following the fitting of the microcontroller and the output driver for the SSR, an external AC supply, SSR, and mains lamp were connected.

Instead of the previously mentioned SSR from TE, part SSRD-240D25A, a Multicomp MPKSI240D10-L(070) was selected. The control voltage for the Multicomp part is between DC 4 – 32 V, meaning an installation can be configured with one or two SSR devices. The clip below shows a lamp connected through the SSR powered by a transformer. The PSoC was programmed to toggle the SSR control input.

For reference, the output of the SSR was captured on an oscilloscope.

SSR Output

Status and Emergency Stop LEDs
The EAO illuminated pushbutton featured in the original drill press design was listed as superseded and replaced with the EAO part 84-5241.2B20. The original code was updated to flash the status LED, indicating the code was operating. No changes were needed for the Emergency Stop LED. In the clip below, both LEDs are shown operating.

In the next post, the input circuitry will be fitted and tested.

Gravity Lightning Sensor Adaptor Board for Arduino

2025-09-14T16:08:00.000+08:00

Introduction
This short post contains details on an Arduino-compatible circuit board (board) to carry the Gravity lightning sensor module.

Custom Shield
In a previous blog, a custom Arduino board with a ScioSense AS3935 lightning sensor was designed. Instead of using a dedicated design, a Gravity Lightning Sensor Module (SEN0290) was used in conjunction with a simplified board to carry the module. This board, with the sensor module, could easily be assembled in educational environments when required. The Gravity module is commonly connected to an Arduino with jumper cables, however a custom board was created to provide a permanent fixture.

Simplified Gravity Sensor Board for Arduino

Circuit Board Build
The board consists of a few connectors for the Arduino and the sensor module. The custom board was designed to use a standard 4-pin to 4-pin sensor cable to connect to the Gravity module.

Grove 4-pin through-hole connectors were chosen. The pin mapping on the 4-pin connectors for the I2C was adjusted to account for the difference between the Gravity Sensor and the Grove RGB LED Matrix.

Circuit Board with Gravity Sensor Module

Test Data
After completion of the hardware pictured above and connection of the module to an Arduino Uno, the example ‘DFRobotAS3935LightningSensorDetails.ino’ code was uploaded to an Arduino Uno.

Arduino Sketch for Circuit Board with Gravity Sensor

On running the Uno, various noise sources in the development area resulted in continuous ‘Disturber discovered!’ messages. After some tweaking of the Arduino example, the settings in the code listed below yielded more stable lightning measurement results.

Changes in setup
lightning0.setOutdoors();
lightning0.disturberDis();
lightning0.setNoiseFloorLvl(1);
lightning0.setWatchdogThreshold(1);
lightning0.setSpikeRejection(1);

Below is a contiguous debug output from the Arduino debug running the sketch ‘DFRobotAS3935LightningSensorDetails.ino’ with the above modified settings.

DFRobot AS3935 lightning sensor begin!
set up for outdoor operation
AS3935 manual cal complete
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 0
Reg 0x05: 0
Reg 0x06: 0
Reg 0x07: 10
Reg 0x08: 12
0
Lightning occurs!
Distance: 10 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 140
Reg 0x05: 45
Reg 0x06: 0
Reg 0x07: 10
Reg 0x08: 12
0
Lightning occurs!
Distance: 5 km
Intensity: 10
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 79
Reg 0x05: 203
Reg 0x06: 2
Reg 0x07: 5
Reg 0x08: 12
10
Lightning occurs!
Distance: 10 km
Intensity: 4
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 201
Reg 0x05: 39
Reg 0x06: 1
Reg 0x07: 10
Reg 0x08: 12
4
Lightning occurs!
Distance: 10 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 115
Reg 0x05: 9
Reg 0x06: 0
Reg 0x07: 10
Reg 0x08: 12
0
Lightning occurs!
Distance: 10 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 97
Reg 0x05: 48
Reg 0x06: 0
Reg 0x07: 10
Reg 0x08: 12
0
Lightning occurs!
Distance: 10 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 208
Reg 0x05: 41
Reg 0x06: 0
Reg 0x07: 10
Reg 0x08: 12
0
Lightning occurs!
Distance: 10 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 108
Reg 0x05: 35
Reg 0x06: 0
Reg 0x07: 10
Reg 0x08: 12
0
Lightning occurs!
Distance: 10 km
Intensity: 1
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 155
Reg 0x05: 101
Reg 0x06: 0
Reg 0x07: 10
Reg 0x08: 12
1
Lightning occurs!
Distance: 14 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 233
Reg 0x05: 25
Reg 0x06: 0
Reg 0x07: 14
Reg 0x08: 12
0
Lightning occurs!
Distance: 14 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 159
Reg 0x05: 13
Reg 0x06: 0
Reg 0x07: 14
Reg 0x08: 12
0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 0
Reg 0x05: 0
Reg 0x06: 0
Reg 0x07: 27
Reg 0x08: 12
0
Lightning occurs!
Distance: 27 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 43
Reg 0x05: 6
Reg 0x06: 0
Reg 0x07: 27
Reg 0x08: 12
0
Lightning occurs!
Distance: 17 km
Intensity: 1
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 144
Reg 0x05: 73
Reg 0x06: 0
Reg 0x07: 17
Reg 0x08: 12
1
Lightning occurs!
Distance: 27 km
Intensity: 0
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 65
Reg 0x05: 21
Reg 0x06: 0
Reg 0x07: 27
Reg 0x08: 12
0
Lightning occurs!
Distance: 12 km
Intensity: 2
Reg 0x00: 28
Reg 0x01: 17
Reg 0x02: 193
Reg 0x03: 32
Reg 0x04: 216
Reg 0x05: 159
Reg 0x06: 0
Reg 0x07: 12
Reg 0x08: 12
2

Gerber and Lightning PCB Parts

Lightning (PCB) Gerber

Lightning Project Parts

Item	Description	Quantity
1	Gravity Lightning Sensor Module (SEN0290)	1
2	Lightning PCB	1
3	Grove 4-pin through-hole	1
4	Grove 4-pin to 4-pin connector cable	1
5	Arduino stackable headers	1
6	Header pins for Gravity IRQ connection	1

Republishing a WS2812 PSoC Creator Project

2025-08-13T18:39:00.001+08:00

Introduction
This short blog republishes a PSoC Creator project that uses a WS2812 component. The WS2812 is an addressable RGB LED, as seen in common devices such as LED strips. The original post with the PSoC Creator Project, ‘WS2812 and 5LP @ 48 MHz’ was posted in the Infineon Developer Community with the project named ws2812_test.cywrk_.Archive01.zip.

Reason to Republish
Four development boards, the micro:bit, Arduino, PSoC, and STM, were chosen for comparison. Most of those boards have been or are currently used in education, and they have a broad sample of projects with code spread across community forums and sites.

Project Example to Compare Development Boards
The addressable RGB LED (WS2812B) was chosen as the example project since LED strips are engaging with students. Example projects were found for all but the PSoC4 part CY8C4245AXI-473. The Modus Toolbox PSoC development environment from Infineon supports NeoPixels, but an example did not seem to be available for the PSoC4. The target audience for this project was at the education level, so off-the-shelf and ‘working’ examples were preferred.

Using Modus Toolbox, the CY8C4245AXI-473 PSoC microcontroller was not listed under the ‘Select device part numbers'.

Modus Toolbox BSP Assistant - Device Part Numbers

A related development kit, CY8CKIT-042, associated with the same PSoC4, was not listed under the Modus Toolbox ‘Select BSP template’.

Modus Toolbox BSP Assistant - Template

Understandably, the target PSoC is an older device, so some limitations were anticipated. Of course, a PSoC6 development kit could be used with the NeoPixel LEDs, but that was hardly a fair comparison against the slightly slower micro:bit or Arduino.

Finding a WS2812 PSoC4 Example Project
A WS2812 library was available for PSoC5, CY8C5888-LP097, by the author, Mark Hastings (Cypress Semiconductor). The example project for the WS2812 was taken from the Infineon community forum, but the project is several years old and contains broken component dependencies.

Later, I was to find another PSoC WS2812 project from the same author called FunWithLEDs. This project contains comprehensive examples of the WS2812.

Rebuilding the WS2812 Example Project
Opening the Top Design in the WS2812 PSoC5 project, some missing components were shown.

Missing Components in PSoC Top Design

The missing library was not included with the WS2812 project, so this was found on another site and copied into the project's root folder.

Added WS281xlib to Project Folder

To correct the missing library component in the PSoC project Top Design, the Dependencies menu in PSoC Creator was used to perform an update.

PSoC Creator Dependencies - StripLightLib Error

The existing dependency for the WS2812, called StripLightLib, was removed.

Lastly, the dependency for WS281xLib was added to the project dependencies, now pointing to the copy in the project’s root folder.

PSoC Creator Dependencies - WS281xLib

The downloaded WS281xLib contains the StripLightLib library and several others worth exploring.

Contents of WS281xLib Folder

The missing component issue was resolved in the projects Top Design, as pictured below.

Updated Components in PSoC Top Design

Compiling the project resulted in no further issues.

Complied WS2812 PSoC Creator Project

The PSoC target was changed to the CY8C4245AXI-473. Finally, the development board was programmed and subsequently used for the development kit evaluation.

Downloads
The dependency WS281xLib and the updated project for PSoC5, built for PSoC Creator 4.4, are available below for download. All intellectual property rights and licenses for the libraries and PSoC Projects, including those belonging to Mark Hastings, Cypress Semiconductor, and related parties, are retained and owned by those entities.

WS281xLib

ws2812_test

Drill Press Controller Update Part 2

2025-07-31T19:56:00.009+08:00

Introduction
This blog details the completion of the drill press controller's printed circuit board (PCB) layout, a partial build of the power supply and testing.

Model of ESTOP PCA Mated to the Enclosure

Placement of New Components
In the previous post, the PCB shape was defined to suit the enclosure. In this post, the component placement and board routing were performed. Even though the design has a relatively low component count, attention was still paid to the mains (AC-DC) power supply and the low-voltage signals. Isolation and component clearances were made a priority.

Unrouted ESTOP Controller PCB

In the above capture, the AC to DC power supply (PSU1) is located on the PCB's left side. The right side of the PCB contains low-voltage parts, such as the microcontroller, input and driver devices.

Unpopulated PCB Housing
After the component placement was finalised, a 3D model of the PCB was generated using the PCB design software. This approach was taken to check for mechanical interference between the PCB and the enclosure model. The check between models was achieved using Fusion 360.

PCB Mated with Enclosure Base

The design uses the connectors provided with the enclosure.

PCB Mated with Enclosure Base and Cover

With no interference detected between objects, the PCB was routed.

Routed PCB and Layers
The PCB was designed using a standard 4-layer 1.6 mm PCB stackup provided by the manufacturing house.

PCB Top Layer

PCB Mid Layer 1

PCB Mid Layer 2

The PCB bottom layer was a copper fill under the low-voltage section and not shown in this post.

Manufactured PCB and Population
To populate a new PCB, I prioritise installing the power supply first. However, as the controller PCB is double the size of the reflow device (e-Design Miniware MHP50), more difficult parts were soldered first.

Reflow Part on a MiniWare

The driver chip with an exposed pad was reflowed first.

Power Supply Population
Next, out of the two onboard power supplies, the discrete switch-mode DC 5 V regulator was fitted to the board.

Power Supply Bench Test

Testing was performed by directly supplying power to the relevant connections on the board. The turn ON voltage was noted at 6.8 V with the unloaded accuracy better than 2 %. With a 165 mA resistive load, the voltage regulation was better than 0.6 %. However, with a 330 mA load, the voltage regulation fell to 3.6 % which was likely due to the inductor. A different inductor will be tested in the next post, together with the additional PCB components.

Salvaging Components from an Atom LED Baton

2025-06-29T13:26:00.001+08:00

Introduction
This brief blog details the salvageable components from the circuit boards of a mains-powered LED light baton manufactured by ATOM.

ATOM Baton Nameplate

Attempting a Repair
When the LED baton, Atom part #AT9877, initially failed to switch ON, the initial thought was that a repair should be possible. Disassembling the unit and checking the control board revealed some damaged resistors.

Damaged Resistors on Circuit Board

After replacing the resistors and retesting the baton, it became apparent that multiple components on the board had failed. The additional failed components included the main switching FET and, after a subsequent test, the onboard fuse. Although a repair seemed feasible, reliability was in question, so the part salvage route was instead chosen.

Parts Salvage
As the baton was already partially disassembled, the control board was easily removed. Two plastic holders were fitted to the ends of the board, and then those clips were fixed into the baton’s metal housing. The board mounting solution is an interesting alternative to mounting holes, which are usually included on circuit board designs.

Plastic Circuit Board End Clips

The wires to the control circuit board were cut, and the control board assembly was removed. Remaining fitted to the baton's chassis, which could be salvaged, were solid core mains cable, the LED boards and some fixings, including terminal blocks.

Each of the two LED boards was fixed in place with seven plastic pins, as shown in the image below. The clips were removed by pushing them from the other side of the baton.

Plastic Clips Holding LED Circuit Boards to the Baton Chassis

The 60 LEDs per board were checked using the diode test on the multimeter; both LED boards could be salvaged or kept for similar LED baton repairs.

LED Strip Markings

Turning attention back to the control circuit board, this was a double-sided (population) design. The control board consisted of surface mount parts on the copper (solder) side and through-hole components on the opposite side. Surface-mount parts were held to the circuit board with an epoxy adhesive, such as the Chip Quik AD1-10S or Henkel Loctite 3621, making reworking or salvaging parts difficult. The benefit for the manufacturer, however, is that this design results in a simplified process during soldering (usually reflow).

Baton Control Board - Solder Side

If easily removed, the diodes (red box in the solder side image) can be salvaged from the solder side of the circuit board. The two larger rectifier diodes marked as US5M are from the manufacturer Suntan.

A datasheet for the main switching FET (yellow box in the solder side image) could not be sourced, and the part number for the 8-pin controller was not easily readable.

Baton Control Board - Top Side

Reviewing the through-hole component side of the control board, the combination of six inductors and chokes (purple boxes in top side image) could be salvaged with minimal risk of damage.

The bridge rectifier (green box) from NextGen components, part KBP210, could be removed and tested.

The manufacturer for the majority of the electrolytic capacitors (red boxes) was Axboom. The three large mains rated 47 uf 350 V devices showed no signs of damage or bulging and could be salvaged.

Long or larger components, such as the capacitors on this board, are secured with white glue or silicone, although this material can easily be cut off.

There is a safety capacitor (blue box) on the board marked with JNC, JY332M; a datasheet could not be found. This appears to be a 400 V AC 0.0033uF Y5U capacitor, and although the Y5U specification drifts when the temperature changes (image below), the part may be useful for other designs or repairs.

Example - Y5U Safety Capacitor vs Temperature

The varistor (black box) on the AC supply appears to be from SONGLONG LISHANG, part 07D471K. This varistor could be tested and used for repairs.

Although the fuse was damaged on this baton, Littelfuse TE5® 392 series markings T1AL250V, it could be salvaged on a working control board.

Dill Press Controller Update

2025-05-31T13:39:00.003+08:00

Introduction
This blog details improvements to a drill press controller created in a previous blog.

Why an Update?
With features such as sensing a stalled chuck, the drill press controller project was something of an experiment for home. Enquiries to this day persist for a ‘user-friendly installable’ version of the drill press controller. As many users seem to prefer a ready-to-go solution, the circuit board change in this post is a step towards simplifying the original controller design, but with some experimental improvements.

What Consolidation and Improvements?
The external DIN rail DC supply from the previous design could be incorporated onto the updated controller board. To fit an AC to DC module to the controller board, however, the controller enclosure would need to be changed from the original type.

Additionally, the AC contactor, which disables the drill press motor when an ESTOP event occurs, was identified as a space-consuming item. A subsequent post will review SSR (Solid State Relay) testing and, if useable, replacing the contactor.

Changes to the Design
Integrating an AC to DC supply onto the circuit board raised some technical questions. Firstly, what voltage should the DC output be? The second question is whether the voltage is suitable for other components in the system. Included in the list of other components are the SSR inputs and existing hardware, such as the ESTOP pushbutton LED.
For testing, a high-current dual form A SSR TE part (SSRD-240D25) was chosen.

TE SSRD-240D25 Solid State Relay

New Enclosure
Using the circuit board dimensions from the original controller as a guide, an enclosure from the manufacturer, Phoenix Contact, part 1311009 (BC 107,6-KIT-U11-7035+4SPTA12), was chosen. This part was selected because it was a two-part case with circuit board mounting, supplied with terminal circuit board terminals, and was affordable.

Phoenix Contact Enclosure #1311009

Schematic Changes
An AC-DC brick from Vigortronix was selected with a DC 12 V output. The VTX-214 series is manufactured with several DC output voltage options.

Updated Power Supply Schematic

As an experiment, a single input PLC device from Maxim was chosen to replace the previous input circuit.

Updated Input Schematic

In the previous design, the contactor coil was powered by two driver chips. For the updated design, the output was changed to instead drive the two enable inputs of the SSR or a similar device.

Updated Output Driver Schematic

Circuit Board Size and Shape
The technical datasheet for the Phoenix Contact enclosure does not appear to provide a dimensioned circuit board example. However, there is sufficient information in the technical drawing to define the circuit board shape. In fact, the 3D model of the enclosure from the Phoenix Contact website also contains an excellent example of circuit board mounting options. In the image below, Fusion 360 was used to hide the outside case of the enclosure.

Example of Circuit Boards in Phoenix Contact STEP Model

To validate the circuit board shape in the circuit board design software, the Phoenix Contact STEP model was required without all the example board options. Fusion 360 was used to suppress all but the plastic base in the STEP file. This STEP file was imported into the circuit board software to validate the circuit board shape.

Example of STEP File Imported into Circuit Board Design Software

In the next blog for the updated controller, the PCB layout is completed.

Model Rocket Launcher WiFi ESP8266 Part 4

2025-04-30T19:05:00.005+08:00

Introduction
This blog is a brief update following on from Part 3 of the ‘Wi-Fi-controlled rocket launcher’. A design to replace the lead-acid battery in the launcher was assembled.

Some field shots of the updated launcher are provided at the end of the post.

18650 Replacement for Lead Acid Battery
A printed circuit board (PCB) with two 18650 batteries was designed to replace the 12 V lead-acid battery used by the launcher.

The operating voltage of the launchers' ESP32 controller and the output drivers is around 3.3 V, meaning the parts were suitable for operation with the 18650 voltage. However, the main DC-DC converter (LMR50410YFQDBV) would need to be changed or bypassed, as its operating voltage is 4 – 36 V. The standard operating voltage of a single 18650 cell drops below the 4 V threshold of the DC-DC converter.

The Keystone Electronics 18650 battery holder, part #1043, was chosen for the PCB design. When selecting parts in the initial PCB layout, two 1043 battery holders were more cost-effective than a double 1850 holder, Keystone part #1049. The Keystone double battery holder had become the cheaper option at the time of writing.

Dual 18650 on PCB

The dimensions of the PCB were made to fit into the existing 3D printed launcher case.

Dual 18650 PCB in 3D

After the PCB was manufactured, a single Keystone battery holder was fitted. For connection compatibility with the spade tabs on the lead acid battery, spade connections were fitted on the PCB using TE Connectivity part #60465-2. As can be seen in the image below, the spade connections were secured to the PCB with M3 mounting hardware.

Partially Populated 18650 Board

Out of curiosity, the DC-DC converter on the launcher was run from a single 18650. First, the previous voltage divider created by the resistor pack RP1 was removed. The shutdown input on the DC-DC converter (LMR50410YFQDBV) was then connected to the supply (VIN) with a 10 R resistor.

Existing DC-DC Converter Shutdown Circuit

Modified DC-DC Converter Shutdown Connection

Using a fully charged 18650, the launcher powers ON briefly. When the 18650 voltage drops below 4 V, the DC-DC converter fails to turn ON and the output voltage becomes unstable. Having the PCB with different 18650 connection options may be part of the next board review.

Field Tested Unit
The two launches below are taken from a recent rocket day.

Salvaging Components from DPF-HD1000

2025-03-30T18:54:00.001+08:00

Introduction
This post looks at electronic components that could be salvaged from a Sony digital photo frame, DPF-HD1000 (circa 2010).

Tear Down
Four plastic screws secure the two halves of the photo frame case. A thin prying tool was used to release the internal plastic clips.

DPF-HD1000 Front Cover Removed

Removing the front panel shows the LCD and two peripheral items, an IR sensor and an LED strip.

Internals of the Photo Frame
Shifting the position of the display shows the main Printed Circuit Assembly (PCA) and the board to peripheral connections.

DPF-HD1000 with PCA Exposed

The IR receiver was connected with a 3-pin cable to the main PCA. The markings on the sensor appear to be 28m5 and E23, but there is no data available for the part online. The connections to the sensor could possibly be determined from the cable colours.

DPF-HD1000 LED Logo Board

The small LED PCA was labelled ‘logo LED board’ circa 2011. This board was used to illuminate the Sony logo built into the front plastic cover.

DPF-HD1000 LED Logo Board Powered

From the website Panel Look, the LCD appears to be from CPT, although discontinued, and could be used for repair or paired with a converter board capable of driving 60-pin flat flex cables from various interfaces such as USB.

DPF-HD1000 LCD Part Number

After removing the 4 screws retaining the PCA, the entire electronic assembly could be removed.

DPF-HD1000 Complete Electronics Assembly

Disconnecting all the peripherals from the PCA, attention turned to some interesting components on the main PCA. The PCA was labelled ‘Sony Basic 10DW MP’.

Possible PCA Component Salvaging
The USB connectors, surface mount and vertical switches could be salvaged from the PCA. The combination card holder on the PCA was an interesting component (large component on the right of the PCA); no data could be found from the A238B marking on the device.

DPF-HD1000 PCA Side 1

Upon reviewing the passives, inductors and the common mode filter near the DC jack (bottom right) these could be salvaged and reused. Due to the age of the PCA, the SMT electrolytic capacitors are not recommended for salvaging, although they did appear in near-new condition.

For active devices, the single linear regulator 1117T near the SD card holder could be salvaged.

DPF-HD1000 PCA Side 2

Flipping the PCA shows several chips, connectors for the peripheral devices and a smattering of passives. If any external devices, such as the IR sensor, were earmarked for salvage, the surface mount connectors could also be salvaged from the PCA.

To the left of the main Amlogic controller is a surface mount switch which may be responsible for detecting rotation (movement) of the display. When shaking the PCA, the internal mechanism can be heard moving. The component marking is EnSky, however no data could be located on the switch.

There is an oscillator, possibly 24 MHz (middle PCA), driving the Amlogic controller and a watch crystal for the on-board RTC (PCA bottom right) that may be useable.

An ELNA button supercapacitor, rated at 3.3 V 0.22 uF, provided backup for the RTC. Looking at the supercapacitor, corrosion was sighted on the case of the device and therefore not useable.

Corrosion on Supercapacitor

The main controller AML6236-VB-B is not listed on the Amlogic website and is likely not worth salvaging.

For storage, Sony opted for a Samsung 2 GB eMMC, part number KLM2G1HE3F-B001 (far left on PCA2). While this component does not appear to be manufactured any more, it would be a great device for experiments. The PCB model still appears to be available (SnapEDA). Even though the component may need to be reballed when fitting the component to a new PCA, connection to micros such as ST or Microchip would most likely be possible.

The 512 Mbit DDR1 memory was provided by Etrontech, part EM6AB160TSD-5G. This part could be used for repairs.

Interfacing the Amlogic controller to the LCD was a Texas Instruments flat panel driver part number SN75LVDS83B. The datasheet is an interesting read and even contains a good summary of PCB layout techniques.

Some other active components on the PCA are the serial flash, switching and linear regulators, speaker driver and RTC. There is also an unmarked chip on the board whose purpose is not clear. Many of these components could be salvaged depending on requirements.

Component Salvaging Example
Often questions posted after salvaging blogs relate to how components are removed from PCAs. As an example, consider the removal of the DC jack from the PCA.

Setup for Component Removal

The jack component is a 5-pin device that could be desoldered although in this example it was removed using a heater plate. Firstly, all the components on the opposite side of the DC jack were removed. These components consisted primarily of passives. This side of the board was made as flat and clean as possible. Then a heater plate, in this instance a MiniWare MHP50, was used to preheat the side of the PCA where the passives were removed (beneath the DC jack). Shortly after the heating cycle, a reflow cycle was run to pry the jack from the PCA. This technique certainly cannot be used for every board and component as the component population density and board construction can have significant effects on heating.

Salvaged DC Power Jack

Other tools such as a hot air desoldering tool or a small temperature controlled oven may be better suited for the removal of specific components.

Transponder Coil Test

2025-02-28T11:28:00.000+08:00

Introduction
This short post details the testing of the transponder portion of the tank circuit used for the ScioSense AS3935 lightning sensor.

AS3935 Block Diagram (Courtesy Sciosense B.V.)

Sensor Board for Arduino (Educational)
A printed circuit board (PCB) was designed for the ScioSense lightning sensor which was paired with an RGB LED (8x8) matrix as a visual output device for lightning intensity. The PCB design uses the common Arduino shield footprint to suit a controller such as the Uno or another compatible controller.

3D View of Lightning Sensor PCB

Tank Circuit Testing
After reading comments from several forums regarding sensitivity concerns with the AS3935, I wanted to check the Q-factor of the recommended LC resonant tank circuit for lighting detection. The transponder manufacturer, Coilcraft, has an article describing testing with a Helmholtz coil however I was interested in driving the recommended tank circuit with the function generator and then measuring the resonance with a second transponder coil connected to a scope.

Coil Coupled Tank Circuit Measurements
Using the two-board setup as pictured below meant that the distance and alignment of each board (transponder coils) affected the measurements. The placement of the transponders in proximity to each other impacts the field coupling. Field coupling is explained well at this Electronics Tutorials site.

Tank Circuit and Transponder Measurement Test Setup

During the test setup, the highest coupled transponder voltage on the receiver transponder was measured using an oscilloscope. The two boards were fixed in position for consistent measurements. Measurements using this test process are not perfect because of the coupling factor between the coils (not unity) and mutual inductance can also affect measurement accuracy.

Tank Circuit Measurements
The datasheet for the AS3935 recommends a 10 k resistor in parallel with a 1 nF capacitor and the transponder coil for the tank circuit.

Schematic of Tank Circuit on Test Board

A second board with only the transponder coil fitted served as the detector through a connection to an oscilloscope.

The signal generator frequency was varied and measurements were taken using an oscilloscope. The approximate centre frequency (resonant) and the corresponding 3 dB points were determined during testing.

From the centre frequency measurements and the 3 dB points, the Q factor was calculated. Three different resistor values were tested and the table below shows a plot of the resistor values and the calculated Q factors. For the recommended tank circuit, the resonant frequency was around 494 kHz.

Tank Circuit - Measurement Data

Tank Circuit - Plot of Resistor Value vs Q-Factor

As a validation test, the FFT function on an oscilloscope was used to view the changes in the resonant frequency of the tank circuit as the the signal generator frequency was varied.

Tank Circuit Measurement Validation using Field Probe

To perform the FFT measurements, a near-field probe (Beehive Electronics) was connected to a wideband amplifier and then connected through to an oscilloscope.

Captured in the image below is the approximate resonant frequency of 488 kHz. The test board was fitted with the suggested design, a 10 k resistor, 1 nF capacitor in parallel with the transponder coil.

Tank Circuit - FFT Measurement

Final Thoughts
A standalone transponder coil was used in this post to show that a parallel RLC circuit on a different circuit board was resonating. Validation of the resonant frequency using a field probe indicated that the measurement difference between using a second transponder coil for measurement, or a field probe was less than 2 %. For accurate resonant frequency measurements, factors such as mutual inductance in the measurement device and the equipment under test should be accounted for.

Crosstalk Test PCB (Educational)

2025-01-19T15:28:00.000+08:00

Introduction
The Printed Circuit Board (PCB) design in this post was inspired by the well-known signal integrity educator, and professor, Eric Bogatin. The board design was based on content shown in a YouTube video created to demonstrate crosstalk.

Crosstalk PCB 3D

Why This Design?
Following on from the PCB trace-to-trace crosstalk content created by YouTuber Robert Feranec with guest Eric Bogatin, I wanted to design a simple educational board that would allow crosstalk measurements to be made on a PCB and tested when passive elements were introduced into PCB traces. Crosstalk measurements with series and parallel resistor signal path terminations are common in many PCB designs and this PCB design was designed specifically for series terminations.

Circuit Board Design
A regular 1.6 mm board (FR4) double-sided PCB was chosen for the design. For the copper layers, a reference plane was placed on one side of the PCB and impedance-controlled traces were placed on the opposite side. Using PCB design software tools, the configuration of the trace impedance (width) was tuned for around 50 R impedance giving a 2.8 mm trace width. The 50 R impedance is given a tolerance of + 10 % as this is the standard tolerance for PCB fabrication houses in the local region.


Altium Impedance Profile 50 R for Crosstalk PCB

As a crosstalk PCB design features two signal traces, the spacing between the traces was set at less than a track width to ensure ample signal coupling between traces.

Crosstalk PCB 2D

As the series element, a resistor footprint was included in one of the PCB test traces.

Crosstalk PCB Resistor Linked

This footprint on the PCB provided an option to test with different resistor values and then measure the effects with suitable test equipment. A pulse generator with a fast edge and an oscilloscope are required.

The first setup on the test PCB has the series resistor on the same layer as the signal trace and the second test setup has the resistor on the opposite side to the trace, connected through vias.

Board Build and Initial Testing
For the board assembly, the Molex SMA connectors were fitted. The Molex part number is 0732512120. For the validation test, the resistors on the PCB were replaced with solder shorts.

During testing, the trace with the series resistor is referred to as the aggressor and the nearby sensing trace, is the victim. Further details relating to this setup and a further explanation can be found in the aforementioned video content with Robert Feranec.

First Test Setup with Crosstalk PCB and Pulse Generator

For validation, measurements were taken using an oscilloscope with a bandwidth of less than 500 MHz and a simple pulse generator (Microchip version) designed in a previous blog.

Pulse Generator Frequency

Pulse Generator Rise Time

With the pulse generator providing the 1.4 ns rising edge signal into the aggressor trace (CH2 blue trace), the connector at the near end of the victim trace (CH1 yellow trace) was connected to the oscilloscope.

Near End Crosstalk PCB Measurements

For a second measurement, the two ends of the victim trace were connected to oscilloscope. When the pulse was applied to the aggressor, the signal entering and then reflecting (near and far end) was measurable.

Near and Far End Crosstalk PCB Measurements

Summary
This short post introduced a printed circuit board for testing the behaviour of signals relating to crosstalk measurements. The option to use a series resistive element was included but not tested in this post.

The PCB Gerber files are downloadable using the link below for those who prefer to build the board and perform testing at home, school or in the lab. The Gerber files use the format as defined on this page.

Crosstalk PCB Gerber Files

PSoC I2C Address Scanner (I2C Scan)

2024-12-27T11:06:00.000+08:00

Introduction
This short post covers a change to a PSoC Creator project created by Bob Marlow (Infineon Developer Community) for scanning an I2C bus.

Reason for the Updated Project
While experiencing issues when communicating with a Midas I2C display (MC20805A6W-FPTLWI-V2), the I2C address needed confirmation. Upon testing with a PSoC project (I2CScan) authored by Bob Marlow, the PSoC program did not output a response to the terminal program with an I2C address even though the Midas display was connected correctly to the PSoC. This was curious because the display was newly purchased.

Test Setup - PSoC Development Board with Midas I2C Display

Narrowing the I2C Address Range
Using two hardware connections on the Midas display, the I2C address can be configured for various I2C address options. For testing, the range of the variable I2CAddress in the PSoC code was limited from 0x3A to 0x3F. A short delay (padding between transmissions) was added to the code to make debugging on an oscilloscope easier.

Status = I2C_I2CMasterSendStart(Address,I2C_I2C_READ_XFER_MODE);

The Midas display did not respond to the read command shown above. However, after changing the code to use the I2C write command, the display responded with its expected address.

Status = I2C_I2CMasterSendStart(Address,I2C_I2C_WRITE_XFER_MODE);

Tera Term - Midas I2C Address

The captures below illustrates the I2C replies, when the 0x3F address was used with the read and write transfer modes for the PSoC function I2C_I2CMasterSendStart.

Midas Display - NACK to Read I2C Packet

The ninth bit (left MSB bit first) in the SCL clock train (yellow trace) in the above trace shows that the corresponding position in the SDA trace (blue trace) was high and therefore represents a negative acknowledgement (NACK) to the read command; the same bit position on the trace below has a low on the ninth bit (blue trace) represents an acknowledgement (ACK) to a write command.

Midas Display - ACK to Write I2C Packet

For further information, see Figures 6 and 7 in the TI document ‘Understanding the I2C Bus’ for waveforms relating to I2C ACK and NACK responses.

Code Changes
The code change mentioned in the above paragraph was implemented in the PSoC TestI2CAddress function located in 'main.c'. Other changes were made in main to suit the terminal program TeraTerm.

Testing Other Devices
To ensure the code change would work with other devices, two other I2C devices were tested; an Adafruit SI1145 light sensor and an INA219 current sensor.

Test Setup - PSoC Development Board with SI1145 Sensor


Tera Term - I2C Address from SI1145 Sensor

Test Setup - PSoC Development Board with INA219 Sensor

Tera Term - I2C Address from INA219 Sensor

Downloads and Disclaimer
The updated PSoC Creator project v1.1, for a PSoC4 device, can be downloaded as linked below. The original project is copyrighted and remains the property of Jörg Meier Software as noted in the project source.

I2CScan-v1_1.cywrk.Archive01.zip

PCB Artwork - Coaster (Dark Chocolate Imprint)

2024-12-17T08:55:00.002+08:00

Introduction
In this blog, the circuit board tool Altium Designer was used to create a circuit board (PCB) coaster with an imprint on the PCB resembling a dark chocolate (cocoa) molecule.

Prototype (Coffee) Cup Coasters

Finding a Suitable Source
Before the PCB design process could be started, a suitable molecule for the PCB imprint was found online. A representation of a molecule that was more uniformly shaped was chosen to suit the shape of the PCB. Such a specific layout may not be available without manipulating the molecule’s layout.

Dark Chocolate Molecule
(Courtesy biobeat.nigms.nih.gov)

The molecule in this post could have been caffeine, tea or several water molecules however for this post dark chocolate was chosen.

Creating the PCB
To begin creating the PCB artwork for the coaster in Altium, a circular arc on mechanical layer 1, with a 90 mm diameter was drawn. The 80 mm PCB diameter used in the previous coffee cup coaster was marginally too small however the overall PCB dimension should be adjusted on a project-by-project basis.

Coaster PCB Shape and Size

Next, the names of the individual chemicals were added as top copper layer strings. The font type sans serif was selected over serif for a modern appearance. Then the bonds between the chemical text were added to the PCB on the top overlay. Various placement and shuffling of top overlay line lengths and text were needed.

Coaster Top and Silk Layers

The next step was to duplicate the top copper layer strings. The layer properties of the copied strings were changed to the mechanical top solder layer and then placed over the top layer strings. This effectively removed the top solder mask exposing the PCB copper. Having a separate top solder layer allows for manipulation of the size and placement.

Coaster Top Solder and Silk Layers

Viewing the PCB using the Altium 3D feature yields the image below for the black solder mask.

Coaster in 3D

PCB Export
The requirements of the desired PCB manufacturer were checked to prepare the PCB artwork for manufacturing. As the files for the PCB manufacturer are usually in the Gerber format, the export settings for the Gerbers should be verified with the manufacturer.

Manufacturing
As noted in other blogs, the appearance and cost of the manufactured PCB may vary based on Production settings. For the PCB in this post, a black solder mask is more expensive than a green solder mask, the latter being more common.

In this post, the PCB thickness was kept at 1.6 mm since this is usually the most cost-effective thickness, a lead-free HASL (Hot Air Solder Levelled) surface finish was chosen over a lead finish and the solder mask was produced in two separate colours, green and black, to exhibit the visual difference. Lastly, the PCB manufacturer's marking was specified on the PCB bottom side overlay.

Downloads
The Gerber file can be downloaded from the link below. The files should be checked before use.

For the Gerbers the Altium export settings here were followed.

Coaster Gerber Files

TDR Pulse Generator (Microchip)

2024-11-10T15:23:00.002+08:00

Introduction
This post continues a previous blog that used a microcontroller driver design to generate a fast-rising edge for educational and bench-testing purposes. The microcontroller (PSoC) in the earlier blog was replaced with a microcontroller from Microchip (ATmega16U2). The board uses the Microchip part and is powered by USB.

Pulse Generator PCB

Why Another Generator
While the previous design using a PSoC microcontroller was received well, the price of a PSoC microcontroller has become twice that of a competing device such as the Microchip ATmega16U2. Consequently, a design was produced to utilise the Microchip microcontroller.

Circuit Board Design
As featured in the previous design, a pulse train is initiated from a microcontroller (ATmega16U2).

ATmega 16U2 for Pulse Generation

The same output driver arrangement was reused on this design however the output driver was changed to a Nexperia 74AHC04 because of the 5 V supply rail (USB). A linear regulator was considered to maintain the supply rails at 3.3 V but was ultimately not included to keep the total cost as low as possible. Five outputs of the 74AHC04 driver are still connected in parallel to individual 249 R resistors. All five outputs are tied together thus providing a calculated 49.8 R at the output, CN2.

Buffered Output for Pulse Generator

Software Design for Output Pulsing
A minimal software (code) project was prepared in Microchip Studio. This application generates a pulse by direct and continuous writes to the microcontroller port. The code to generate the pulses is shown below.


int main(void)
{
	DDRD = 0x08;
	PORTD = 0x00;
	for (;;)
	{
		PORTD |= _BV(PD3);
		PORTD &= ~(_BV(PD3));
	}
}

USB hardware connections were made to the ATmega to allow developers or users to enhance the code further. The ATmega software could be developed to support USB-controlled commands. Below are some links for software that may allow for HID solutions with the USB.

https://github.com/NicoHood/HoodLoader2

https://gitlab.com/arksine.code/HID/-/tree/2.0

A Note on Programming
The post includes details regarding the programming of the Microchip part because this design is intended for the educational system or illustrative purposes.

The 6-way programming connector on the pulse board interfaces with the ATmega. The connections are designed for SPI programming. See Table 3-6 in the Atmel ICE document for information concerning connections between the programmer and Microchip microcontrollers.

SPI Connector Pinouts

For programming of the microcontroller in this blog, the ‘Atmel squid’ connections were made to the pulse generator board as shown below.

SPI 'Squid' to Pulser Board

PCB pad jumper J1 should be shorted with solder to power the external oscillator.

Powering External Oscillator J1

The settings displayed below are taken from the Microchip Studio's, Tools menu, and the Device Programming item. The settings can be adapted based on the functionality needed on the board. For example, the onboard 8 MHz oscillator could be replaced with a different frequency device or the board could be redesigned to suit a crystal.

Microchip Studio ISP Clock Settings

Microchip Studio Oscillator Settings

Microchip Studio Fuse Settings

Microchip Studio Fuse Settings Continued

Testing the Board
Since the output driver voltage rails were changed from 3.3 V to 5 V, the output rise time (10% - 90%) was predicted to be slower.

Prototype Pulser PCA

Drive Voltage from Pulse Tester (Microchip)

Period from Pulse Tester (Microchip)

Signal measurements were again performed on a Keysight oscilloscope with a 20 GSa/s resolution. This board showed a rise time of 1.11 ns when measuring for a rise time of 10% to 90%.

Output Waveform Rise Time from Pulse Tester

Reflectometry Testing
Reflectometry tests were performed with a benchtop oscilloscope. The pulse was connected to the oscilloscope with a BNC Tee adaptor, and the other side of the BNC Tee was connected to a length of coaxial cable.

Pulse Tester as TDR Test Setup

The initially launched and reflected pulses were captured as shown in the image below.

TDR Capture

Engineering Files
The Atmel Studio project, schematic, Gerber and BOM files are available for download using the links below.

Pulse Generator Microchip Studio Project


Pulse Generator Schematic Rev2

Pulse Generator Gerbers Rev2

Pulse Generator Bill of Materials Rev2

Amazon 9.8" Pottery Wheel Foot Speed Control Change

2024-10-31T21:00:00.000+08:00

Introduction
This short blog shows how to replace the speed control device in the foot controller on the Amazon 9.8” pottery wheel. This change may be required for anyone with irregular speed control or a damaged foot speed controller.

Determining the Part Replacement
With the pottery wheel unpowered, the internals of the foot speed controller are accessed by removing three plastic screws located in the base of the foot controller. The foot control mechanism consists of a potentiometer for setting the speed and two gears.

Internals of Foot Speed Controller

To remove the potentiometer, the locking nut was loosened. This allowed removal and part identification.

Original Potentiometer

As shown in the above image, the potentiometer was rated at 4.7 k 2 W. A similar device was located from TE Connectivity part 3-1625931-0 and sourced online.

Replacement TE Connectivity Potentiometer

Items to Address with the Replacement Part
The TE Connectivity potentiometer is a direct replacement for its value (resistance); however, there are mechanical differences with the potentiometer, specifically the solder pins and smooth shaft. Since the original potentiometer was supplied with a D-shaped shaft, the original spur gear could not be reused, so a new spur gear needed to be created.

Original D-Shaft Spur Gear

Down the Spur Gear Road
The spur gear script feature in Fusion 360 was chosen to create a compatible gear. Alternative tools are available for creating a spur gear however these alternatives were not tested for this blog. Two alternative sites may be STL Gears and Gear Generator.

Fusion 360 Spur Gear Script
In Fusion 360, the Spur Gear script is accessed from the Utilities tab under the Add-Ins icon.

SpurGear Script in Fusion360

The settings in the image below were chosen after measuring the original gear, applying them to the spur gear script followed by 3D-printed prototypes. Some important items for the spur gear were the number of teeth, shaft diameter and Fusion 360 calculated Pitch Diameter.

SpurGear Settings in Fusion 360

Fusion 360 Spur Gear Modification
To ensure that the spur gear would not rotate on the round potentiometer shaft, two cutouts were added inside the spur gear shaft area for glue. The cutout changes were made to the spur gear sketch generated by the Fusion 360 script.

Editing the SpurGear Sketch

The images below show the edit to the sketch and updated 3D model.

SpurGear Sketch with Cutouts Added

SpurGear 3D with Cutouts Added

Ultimaker Cura was used to generate a print with a 100 % fill. The Fusion 360 file and STL files are available for downloaded at the end of this blog.

Replacing the Potentiometer
The wiring layout for the potentiometer was recorded. Using a soldering iron, the three wires from the original potentiometer were desoldered.

Potentiometer Wiring Connections

For the replacement potentiometer, the centre pin of the new potentiometer was determined to be the wiper (red wire). In the configuration shown in the image below, pressing the control pedal to the angled position increased the speed. For reverse operation, the yellow and green wire positions on the potentiometer should be swapped. All connections were soldered and covered with a piece of heatshrink.

Wiring for New Potentiometer

The replacement spur gear was printed in PLA and then it was placed onto the potentiometer shaft without glue to ensure it aligned with the other mechanism inside the pedal.

Positioning the Spur Gear

To ensure the gear did not rotate on the potentiometer shaft, glue was added.

Replacement Potentiometer with Round Shaft

Fitting and Setting the Potentiometer Home Position
With the connections finalised and the gear positioned, the locking nut on the potentiometer was hand-tightened.

Mounted Potentiometer with Threadlocker

The pottery wheel was powered and set up to operate from the foot control. In the horizontal position, the potentiometer was rotated so that the pottery wheel did not turn. This corresponds to a speed of 000 on the pottery wheel display. The potentiometer was tightened further. Pressing the foot control to the angled position resulted in a speed of 320.

Maximum Speed Value on Pottery Wheel

Loctite 222 was applied to the thread on the potentiometer to reduce the chance of the potentiometer coming loose.

Lastly, the base plate for the foot control was reattached and secured with the three plastic screws.

Downloads

SpurGear.f3d

SpurGear.stl

Dual Colour LED Matrix Shield (Educational)

2024-09-29T19:46:00.001+08:00

Introduction
This blog shows the hardware used for an Arduino-compatible shield featuring a dual-colour matrix LED.

LED Matrix Shield Mounted on Arduino Uno

Purpose of the LED Matrix
The design was created for educational purposes and to train school-aged programmers. For hobbyists looking for an off-the-shelf solution using LEDs, some related products featuring RGB LEDs are the NeoPixel or for an LED matrix, the D1 Mini from Wemos.

Technology Used
Three shift registers, part 74HC595, were used to drive the 8 rows and 10 columns (matrix 5 red and 5 green LEDs) of the LED matrix from the Arduino Uno. To maintain the design simplicity, no LED buffers were included which would increase the drive current. The 74HC595 from Nexperia fitted to the prototype could provide 25 mA per pin although the maximum current of the shift register is limited to approximately 70 mA.

A buck converter, TI part LMR51606YDBVR was chosen to provide 5V power to the shift register and LED matrix. A higher current DC-DC converter and LED drivers could be utilised for a brighter LED matrix.

Kingbright Dual Colour LED Matrix

For the LED matrix, Kingbright part TBC24-11EGWA was used. At the time of writing the LED Matrix from Kingbright part had become End of Life.

Connections to Arduino
Details are provided on the Arduino website for connecting shift registers such as the 74HC595 to the Uno board. One such example with connections and code is shown in the tutorials.

The shift register connections to the Arduino are the same as the tutorial with the addition of the output enable signal.

To adjust the LED matrix intensity and depending on the characteristics of LEDs, the value of the resistor packs could be changed. During testing the values 68 R and 56 R for red and green LEDs respectively achieved a good balance between current consumption and light output.

LED Matrix Shift Register Connections

Shown in the image below are the pins used on the Arduino Uno for the shift registers and power.


LED Matrix Shift Register to Arduino Connections

Lastly, a DC-DC converter was used instead of the linear regulator on the Arduino Uno. This meant less heat dissipation on the Uno board.

LED Matrix Power Supply

Printed Circuit Board (PCB)
The PCB for the LED matrix shield was designed with four layers however the board layer count could be reduced. Shown below are the external power and internal signal layers. The top layer was a solid copper pour for the 0 V layer and therefore not shown.

LED Matrix Bottom Layer PCB

LED Matrix Mid Layer PCB

Populated LED Matrix
The completed prototype board used pin headers for the LED matrix although the PCB was designed to allow flush mounting of the LED matrix.

Populated LED Matrix Shift Register Side

Populated LED Matrix (Display) Side

When connecting the LED matrix shield to an Uno or similar board, a space between the two boards of at least 13 mm was required. This spacing ensured the LED matrix pins did not cause a short against the USB B connector housing.

Arduino Uno and LED Matrix Fitted Together

LED Matrix Operation & Code
For the example below the Arduino pin mapping shown below was used.

void setup() 
{
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  pinMode(oePin, OUTPUT);
  digitalWrite(oePin, LOW);
}

Some videos of the operation with example code are shown below.

Counting with Rows

  for (int numberToRows = 0; numberToRows < 255; numberToRows++) 
  {
    digitalWrite(latchPin, LOW);
    shiftOut(dataPin, clockPin, MSBFIRST, 0);           // red = 0, all off 31 show green
    shiftOut(dataPin, clockPin, MSBFIRST, 0);           // green = 0, all off 31 show red
    shiftOut(dataPin, clockPin, MSBFIRST, numberToRows);   // turn on all columns
    digitalWrite(latchPin, HIGH);
    delay(100);
  }

Counting with Columns

for (int numberToColumns = 0; numberToColumns < 32; numberToColumns++) 
  {
    digitalWrite(latchPin, LOW);                                 
    shiftOut(dataPin, clockPin, MSBFIRST, numberToColumns);   // red = 0, all off 31 show green
    shiftOut(dataPin, clockPin, MSBFIRST, numberToColumns);   // green = 0, all off 31 show red
    shiftOut(dataPin, clockPin, MSBFIRST, 255);                        // turn on all rows               
    digitalWrite(latchPin, HIGH);    
    delay(100);
  }

Dual Colour Change

  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, 0);   // red = 0, all off 31 show green
  shiftOut(dataPin, clockPin, MSBFIRST, 31); // green = 0, all off 31 show red
  shiftOut(dataPin, clockPin, MSBFIRST, 255); // turn on all rows
  digitalWrite(latchPin, HIGH);
  delay(200);
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, 31);    // red = 0, all off 31 show green
  shiftOut(dataPin, clockPin, MSBFIRST, 0);     // green = 0, all off 31 show red
  shiftOut(dataPin, clockPin, MSBFIRST, 255); // turn on all rows
  digitalWrite(latchPin, HIGH);
  delay(200);

Downloads


LED Matrix Gerber

LED Matrix Schematic

LED Matrix Top Overlay

LED Matrix Bottom Overlay

Making Amazon 9.8" Pottery Wheel Foot Switch Detachable

2024-08-31T13:59:00.001+08:00

Introduction
In this blog, a modification was made to the generic 9.8” pottery wheel supplied by Amazon. A connector was fitted to allow the foot pedal to be removed.

Amazon Pottery Wheel (Courtesy Amazon)

Pottery Wheel Foot Switch Cable Location
Protruding from the underside of the pottery wheel is a white cable that connects the foot pedal to the pottery wheel’s electronic controls. The connection of the white cable was altered to fit a connector allowing disconnection for movement or storage of the pottery wheel.

Underside View of 9.8" Pottery Wheel

The white cable passes through a hole in the pottery wheel's metal chassis. The hole's internal diameter is approximately 14.8 mm. Depending on the type of chassis mount connector selected, the hole may already be suitable for that connector. Alternatively, an inline pluggable connector could be fitted instead of the chassis mount connector.

An M12 chassis mount and an inline connector set from TE Connectivity was chosen for this project.

Pluggable Connectors
Fitting the M12 chassis mount socket connector started with cutting the white cable. Sufficient cable length was left protruding through the hole to allow for connecting to the chassis mount connector. The cable was moved to the side temporarily while the hole was made larger with a stepped drill bit.

The three wires in the foot pedal cable, red, yellow and green were stripped and tinned. A small length of heatshrink was fitted on each wire. The cable was passed through the retaining nut and then the hole in the chassis. The wires protruding through the hole were soldered to the M12 socket.

Pottery Wheel Side - M12 Chassis Mount Socket

For the mating side of the connector, an M12 plug was fitted to the cable attached to the foot pedal.

Foot Switch Side - M12 Inline Plug

The M12 TE Plug used screw terminals instead of solderable pins. The stripped wires were connected in the same order as the socket.

An operational test was performed before finalising the heatshrink and tightening the M12 nut.

Pottery Wheel M12 Connector Test Fit

The assembled foot switch is pictured below.

Updated Foot Switch Assembly

The connected assembly of M12 connectors is shown below.

Completed M12 Connector Assembly

MAX22191 with Periodic Signals

2024-07-21T10:25:00.000+08:00

Introduction
This blog provides measurement information on the maximum input frequency of the Analog Devices digital input device MAX22191. Measurements were taken for the periodic signal types square, sine and sawtooth.


Functional Block Diagram of MAX22191 (Courtesy Analog Devices)

Device Behaviour with Steady State Signals

A small test board was designed for testing the MAX22191.

Circuit for MAX22191 Test Board

The circuit for the MAX22191 followed the datasheet example, consisting of a protection diode (TVS) on the input and an LED on the output. The test board was configured so that the MAX22191 was powered from an external supply.

MAX22191 Development Board

With the MAX22191 powered, the input voltage to the MAX22191 was adjusted to verify the board functionality. The supply (DC 5 V) and input voltages for MAX22191 were controlled using two supplies on a Rigol DP832 power supply.

MAX22191 Setup for Input Voltage Level Tests

Measurements with the test board showed that the upper input threshold voltage (ON) was approximately DC 9.5 V and the lower threshold voltage (OFF) was DC 7.9 V, giving a hysteresis of DC 1.6 V. These values are similar to the device datasheet values for the maximum input upper threshold voltage (ON) of DC 10 V and the lower threshold voltage (OFF) of DC 7 V.

Device Behaviour with Periodic Signals
The output of a function generator Rigol DG1022 was connected to the input of the MAX22191 to test the maximum operating frequency. For the periodic signals, the duty cycle was set and then the frequency of the function generator varied. This process was repeated for three duty cycles. The test board was powered with DC 5 V.

MAX22191 Setup for Periodic Signal Tests

The function generator output was set to High Impedance (High Z). An oscilloscope was connected to the input and output of the test board to capture the waveforms. The images in this section show the input waveform as the yellow trace and the output waveform as the blue trace.

Tests - Square
A square wave with a 10 V amplitude (loaded) was driven into the device.

MAX22191 Output Capture for Square Input Signal

For the three duty cycle settings the frequency of the function generator was increased until the output LED controlled by the MAX22191 switched OFF. The maximum frequency was measured when the output voltage from the MAX22191 dropped below 2.0 V. This was an arbitrary TTL limit for comparative purposes only.

For a 20 % duty, the LED switched OFF at 34 kHz however the output signal fell below the threshold at approximately 30 kHz.

MAX22191 Output Capture for Square Input Signal 20 % Duty

For a 50 % duty, the LED switched OFF at 180 kHz and the output signal fell below the threshold at the same frequency.

For an 80 % duty, the LED switched OFF at 260 kHz and output signals fell below the threshold at approximately 230 kHz. Some unexpected waveform behaviour was seen. This did not occur at lower frequencies such as 150 kHz. This could be an artefact of the test setup.

MAX22191 Output Capture for Square Input Signal 80 % Duty

Test - Sine
The LED switched OFF at 123 kHz and the output signal fell below the threshold at approximately 125 kHz.

MAX22191 Output Capture for Sine Input Signal 50 % Duty

Tests – Sawtooth
For a 20 % symmetry setting, the LED switched OFF at 34 kHz and the output signal fell below the threshold at the same frequency.

MAX22191 Output Capture for Sawtooth Input Signal 20 % Duty

For a 50 % symmetry, the LED was still active at 120 kHz (function generator limit) and the output waveform was still measurable.

For an 80 % symmetry, the LED was still active at 150 kHz (function generator limit) and the output waveform was still measurable.

MAX22191 Output Capture for Sawtooth Input Signal 80 % Duty

Detection Levels
The periodic signals were captured as shown in the images below to aid in visualising the voltage detection thresholds for the MAX22191.

MAX22191 Input Output Levels Compared to Output for Square Input Signal

MAX22191 Input Output Levels Compared to Output for Sine Input Signal

MAX22191 Input Output Levels Compared to Output for Sawtooth Input Signal

Arduino Uno R4 Wifi Flash Reprogramming

2024-06-04T21:10:00.000+08:00

Introduction
This short post covers the reprogramming process on the Arduino Uno R4 WiFi (Arduino R4) firmware. The information in this post supplements the content available from the Arduino website with a few additional images. This post is targeted at installations using Windows machines.

The discussions in the Arduino forums for the detection and programming issues on the Arduino R4 can be viewed here.

Reason for Reprogramming the Arduino R4
During software development, a debug message in the Arduino IDE stated that a firmware update was available for the Arduino R4 WiFi. Using the steps below, the module type detected by the Arduino IDE was changed from an Arduino R4 to a WiFiduinoV2 following a firmware update. Reprogramming the Arduino R4 resulted in incorrect operation.

Steps Resulting in Incorrect Firmware Programming
To begin, the computer running the Arduino IDE was connected to the Arduino R4. The Firmware Updater was selected from the Tools menu in the IDE.

Arduino IDE Displaying Correct Board Type

The Arduino R4 was recognised in the IDE as the correct board.

Arduino IDE Firmware Updater

The firmware update process was initiated in the IDE by clicking the Install button.

Arduino IDE Firmware Selection

Firmware version 0.4.1 update on the Arduino R4.

Arduino IDE Firmware Update of Arduino R4

After updating the Arduino R4 firmware, the IDE recognised the R4 as a WiFiduinoV2. This behaviour has been noted in Arduino forums.

Arduino IDE Detecting Different Board

When attempting to build using the WiFiduino2 this results in various compiler issues. The firmware needed reversion.

Arduino IDE Error with Incorrect Board Type

Attempting to repeat the flash process for the Arduino R4 firmware not possible as the board was not recognised as the correct type.

Arduino R4 not Recognised After Flash Update

Using the ESP32 Flash Tool to Restore the Firmware
Fortunately, the Arduino website provides the firmware and tools to reprogram the ESP32 on the Arduino R4 board to restore the type. Some details are contained on the ESP32 Upload page and the main details are available on an associated page here.

Capture from Arduino Website

The Arduino website describes the steps required to reprogram the Arduino R4 flash which, begins with removing the USB (power).
A jumper was fitted to the 3x2 header on the Arduino R4 board.

Arduino R4 WiFi Header with Jumper Fitted

With the Arduino R4 board reconnected to the computer, the batch file for reprogramming was downloaded from the Arduino website here. When executing the batch file, there was an issue detecting the Arduino R4 board and the batch file operation was terminated.

The ESPflash tool was initiated from the command line following the settings shown on the Arduino website. The results of executing the ESPflash tool are listed below.

C:\********\unor4wifi-update-windows\unor4wifi-update-windows\bin>espflashwrite-bin -b 115200 0x0 
C:\********\unor4wifi-update-windows\unor4wifi-update-windows\firmware\UNOR4-WIFI-S3-0.4.1.bin
[2024-06-01T07:32:00Z INFO ] 🚀 A new version of espflash is available: v3.1.0
[2024-06-01T07:32:00Z INFO ] Serial port: 'COM8'
[2024-06-01T07:32:00Z INFO ] Connecting...
[2024-06-01T07:32:00Z INFO ] Using flash stub
Chip type:         esp32s3 (revision v0.2)
Crystal frequency: 40MHz
Flash size:        8MB
Features:         WiFi, BLE
MAC address:   <hidden>
[00:00:17] [========================================]    877/877     0x0 
C:\********\unor4wifi-update-windows\unor4wifi-update-windows\bin>

Closing the command line and opening the Arduino IDE, confirmed that the Arduino R4 board type was restored correctly. This process mentioned in this post was repeated numerous times during testing without any issues.

If the jumper was left in the Arduino R4 and restarted, the board type is detected as a Deneyap Kart G in the IDE.

Arduino IDE Detecting Deneyap Kart G Board

PCB Artwork - Model Rocket

2024-05-29T20:19:00.004+08:00

Introduction
In this blog the circuit board tool, Altium Designer, was used to create circuit board artwork in the form of a model rocket keyring. The recent prototype of the Wi-Fi rocket launcher post inspired this blog.

Model Rocket Keyring

PCB Artwork
To start the project, a black-and-white image of the rocket keyring was downloaded from a suitable website. An image called SpaceShipOne was downloaded from CleanPNG (all credits).

Scaled Rocket Image (Courtesy CleanPNG)

The original image was scaled by 25% before importing into Altium. Shown below is the result of the import. As can be seen by the imported image, the image did not produce solid lines which was required for the keyring.

Imported Rocket Image

Rather than manipulating the PNG file for an improved import result within Altium, the outline of the imported PNG was drawn over with circuit board tracks (traces). For simple shapes such as the rocket, using Altium is relatively easy however many other packages could be used to achieve the same drawing.

Drafting Rocket Primitives

The image below shows the imported image and the hand-drawn image side by side. Minor changes can be noticed on the rocket fins compared to the original image.

Comparison of Hand Drawn and Imported Rocket Designs

One item not included in the circuit board file was the board outline. This is commonly added on a mechanical layer but this was not added to the design. It has been noted that many other free software tools are being used to create circuit board artwork. Therefore, with the alternative software in mind, the board manufacturer was asked to add a circuit board outline.

Manufacturing
For the circuit board manufacturing, the company JLCPCB was used. JLC included a board outline 0.1 mm from the circuit board trace. The final product is shown below.

Model Rocket Keyring

Download
For anyone interested in producing a keyring, the Gerber file pack is available below. A board outline should be spaced at least 0.1 mm from the outermost circuit board traces.

Rocket Keyring Gerbers