EEWeb Projects

Replacement Code Lock for LS7220 base Systems

2013-05-29T00:00:54-07:00

LS7220 is a digital code lock system from LSI Computer System and its dificult to find in many places. The purpose of this article it to introduce some custom made virtual system to replace the LS7220 base systems. This custom system is design using PIC16F628A – 8bit mid range microcontroller unit and its release as an open hardware project.

iPhone Loudspeaker Amplifier

2013-05-23T16:06:05-07:00

The iPhone Amplifier will provide up to 2.50W/CH at 9volts supply Audio input from a headphone jack

This provides sufficient power to drive a small set of speakers such as found in stereo cassette radios or high quality headphones. One of the main complains about I phone is the sever lack of power when attempting to use with high quality headphones. This small amplifier solves this for you and measures when encased 110mm by 60 mm inclusive complete circuit plus battery.

Your own home made Raspberry pi power supply from Scrap

2013-03-14T18:20:41-07:00

I said that I’d make a power supply for you for the raspberry pi

A reliable power supply capable of delivering over 1 amp for the use of the raspberry pi so I have and I’ve used nothing but scrap components from old pcb’s , dumped TV boards, printer boards and all sorts that I could find discarded and left for the poor old rubbish dump So for those of you who like a challenge and want to build your own and here it is

Cell Phone Detector

2013-03-09T10:16:44-07:00

This is a mobile phone sniffer circuit that can detect the signals being used in the GSM (Global System for Mobile Communication) band at about 900 MHz. Since the signals are digitally encoded, it can detect only the signal activity, not the speech or the message contents. A headphone is used to hear the detected signals.

PIC and EEPROM Programmer

2013-03-01T13:26:53-07:00

In this project we are building a JDM programmer that can handle PIC12, PIC16 and PIC18 family microcontrollers and some popular 24C family EEPROMs.

300 Watt MOSFET Real HI-FI Power Amplifier

2013-02-28T12:26:26-07:00

My passion for excellence progressed over the past 40 years to developing sonically superior amplifiers to the highest possible standards, providing life like sound performance.

FPGA Ray Tracer

2013-02-14T10:01:13-07:00

Our initial goal was to realistically render and shade spheres with reflections while being able to navigate through the scene and allow the spheres to bounce and roll around. Once we met this goal, we added anti-aliasing and the ability to render planes as well. Because spheres are particularly hard to draw accurately with non-ray tracing 3-D accelerators and spheres can be used as bounding objects for polygon tracing, we chose to implement spheres first. Planes were added because they can be used as polygons to render more complicated objects with sufficient bounding. We used a NIOSII processor to update the sphere table in hardware so that we could rotate spheres about any axis and have them move without adding significant complexity to the hardware. Rotations and motion were done in floating point on the CPU, making the calculations more accurate than the 24bit 12.12 fixed point representation used in the hardware. All input switches and keys were used to allow motion of the light source, motion of the origin, rotation of the scene, selection of the resolution, selection of the scene if the CPU was not used, the level of reflections, the level of anti-aliasing, reset, the option render planes, and finally telescoping/widening the camera.

Cortex-M3 MCU STM32-based LCD controller

2013-01-28T08:24:04-07:00

This is an embedded system application project finished during my intern at ST Microelectronics (Shanghai) Co.,Ltd. This project provided me a precious hands-on opportunity to independently work on an embedded system application, and developed my skills in schematic design, PCB layout and C programming.

Efficient Yield Estimation and Optimization for a 6-T SRAM Cell

2013-01-15T10:22:58-07:00

A very important aspect of memory design is yield analysis which takes into account the performance of SRAM cells in the presence of process variations. This project involves a study of algorithms for performing yield analysis. Firstly, exhaustive sampling is done which has very good accuracy but requires a large runtime. Next the runtime is greatly reduced by performing importance sampling which gives very good yield accuracy. In the last section, modified adaptive least mean square algorithm is studied which requires very few iterations to converge to the maximum value of yield.

Voltage Controlled Amplifier

2012-10-14T18:41:58-07:00

A voltage controlled amplifier using 2 JFETS produces a simple linear voltage controlled amplifier. One salient characteristic is that the bandwidth is constant over gain changes. It can be controlled with a positive or negative control voltage depending on the type of JFETs chosen.

Cell phone Charger with 1.5 v battery

2012-10-13T12:35:08-07:00

This is the circuit diagram of mobile phone charger with 1.5 v battery, we can also 2 1.2 v(2.4 v) batteries. In 1.5 v battery charge full time is 45 minute & in 2.4 v 30 minutes takes to full charge a mobile phone battery.

Rs 232 Relay Control Board

2012-10-10T14:35:08-07:00

Computer Controlled, relay board designed to be either operated manually via switches on the board or nine way Type Connector via PC or laptop. Provision has been made for USB serial adaptor. The Project utilises PIC Micro technology with windows visual interface written C Sharp utilising Dot Net version 4. It can be interfaced to other adapters Keypad adapter (Optional) or RF receiver (Optional) or Via the Net (Optional) Can be adapted to operate other external attachments such as Automatic Security Gates, Slave Flash or multiple Strobe lights for both professional or amateur photographers

Simulation and Transient Analysis of Analog PWM Input

2012-08-02T07:51:34-07:00

Creating discreet, transistor based analog PWM input circuit. Before creating the board IRL, I made software simulation. Here are the analysis results.

Implementing Adaptive Brightness Control to Seven Segment LED Displays

2012-07-12T10:03:05-07:00

Adaptive brightness control has become a common feature in modern smartphones, HDTVs, PDAs, tablets, and computer screens. The goal of this feature is to conserve power as well as to make the display easier to see in a broad range of illumination conditions. This project illustrates a technique of implementing adaptive brightness control to seven segment LED displays. It consists of a closed loop system that continuously assesses ambient light condition using an inexpensive light-dependent resistor (LDR) and uses that information to adjust the brightness of the display. For the proof of concept, the technique is applied to construct a digital temperature and relative humidity meter that adapts the brightness of the seven segment LED displays to the surrounding lighting conditions. It basically dims the LED display in a dark environment and brightens it when the ambient light level is higher.

Line Following Robot

2012-05-21T01:00:32-07:00

The motors I used for this robot are 2 servomotors modified for speed. You can also use other motors if it’s good enough. I didn’t have any so I modded 2 servomotors.

Independent Design Houses in China

2012-05-05T09:48:54-07:00

In August and September 2011, Embedded Developer LLC, in cooperation with 21IC, China’s leading site for engineers, and 21IDH, the leading site for Independent Design Houses in China, conducted a ground-breaking survey to gain an in-depth understanding of the trends driving the growth and evolution of China’s Independent Design House (IDH) sector. The survey gathered input from over 800 respondents representing all sectors of the electronics industry, including 245 IDHs, 504 customers, 17 component suppliers and 62 distributors and traders.

Car Alarm System

2012-05-04T12:16:45-07:00

The project is almost acceptable of a car alarm system, which could be completed with a transmitter and receiver.

Digital Clock using AT89C4051

2012-05-04T05:00:39-07:00

This is the simple clock which we use in our life regularly. It has three push buttons which use to set the time, date. one is for mode selection and other two for increasing and decreasing.

Water Alarm Circuit

2012-05-04T02:48:57-07:00

this circuits remember us that our tank is near about to get full so that we turn off our motor switch but for this circuit you need a function generator specially

Temperature and relative humidity meter using an inexpensive DHT11 sensor

2012-01-17T17:20:14-07:00

Numerous studies have shown that the indoor temperature and relative humidity at workplace significantly impacts workers’ comfort and productivity. The first step towards optimizing these two ambient parameters is their reliable measurement. This project describes an inexpensive technique of using the DHT11 sensor for measuring temperature and relative humidity in parallel. It uses the PIC16F628A microcontroller to read the sensor output and display the results on a 16×2 character LCD.

PIC Controlled Relay Driver

2011-12-31T12:21:39-07:00

This circuit is a relay driver that is based on a PIC16F84A microcontroller. The board includes four relays so this lets us to control four distinct electrical devices. The controlled device may be a heater, a lamp, a computer or a motor. To use this board in the industrial area, the supply part is designed more attentively. To minimise the effects of the ac line noises, a 1:1 line filter transformer is used.

10 LED VU Meter Project by LM3915 and LM324

2011-12-31T12:20:36-07:00

VU (Volume Unit) meters are often included in analog audio equipments to display a signal level in Visual Units. We are building a mono input VU meter in this project. You can build one pair to use them in stereo mode.

Diffusion limited aggregation

2011-12-21T16:32:04-07:00

A symmetric, shared memory, multiprocessor system was built on an Altera/Terasic DE2 FPGA board. The processors were derived from a stack machine designed at Hiroshima University. A memory switch shares RAM between three processors and a VGA controller. The VGA controller reads memory at 25 MHz, interleaved with an aggregate rate of 25 MHz for the three processors. A minimal set of RAM read/write functions were implemented, including an atomic test-and-set function.

Expandable instrument amplifier from 70W to 300W

2011-12-15T15:32:47-07:00

The TDA 7293 and 7294 integrated amplifiers are not the best for home hi-fi, but very good solution for guitar, vocal, or any instrument amplification if 70 to 300W musical power is enough on the speaker output. The benefit of this amp, no other circuit required for bridge setup, and very easy to make paralleled application, because the preamp section powered off if the 7293 switched to slave mode. Lot of “official” instrument amplifiers using TDA729x solutions, for example Carlsbro GLX100, Marshall MG series, and Marshall Mode Four head. With loud and hq guitar speakers like Eminence have very good results with this simple and cheap amplifier.

Digital Energy Meter

2011-11-30T00:51:44-07:00

An electric meter or energy meter is an essential device that goes with consumption of commercially
distributed energy. It enables systematic pricing of energy consumed by individual consumer as it measures the
amount of electrical energy consumed by a residence, business, or an electrically powered device [1]. They are
typically calibrated in billing units, the most common one being the Kilowatts hour, which is equal to the amount of
energy used by a load of one kilowatt over a period of one hour, or 3,600,000 joules.
Some meters measured only the length of time for which charge flowed, with no measurement of the
magnitude of voltage or current. These were only suited for constant-load applications. Neither type is likely to be
used today. In addition to metering based on the amount of energy used, other types of metering are available.
Meters which measured the amount of charge (coulombs) used, known as ampere-hour meters, were used in the
early days of electrification. These were dependent upon the supply voltage remaining constant for accurate
measurement of energy usage, which was not a likely circumstance with most supplies.
Generally, electricity meters operate by continuously measuring the instantaneous voltage (volts) and
current (amperes) and finding the product of these to give instantaneous electrical power (watts) which is then
integrated against time to give energy used (Joules, Kilowatt-hours etc.). Meters for smaller services (such as small
residential customers) can be connected directly in-line between source and customer. For larger loads, more than
about 200 amps of load, current transformers are used, so that the meter can be located other than in line with the
service conductors [2]. The meters fall into two basic categories, electromechanical and electronic. This paper
dwells on the electronic meter (i.e. the digital meter)
An example of a traditional electromechanical meter is shown in figure 1. It has a spinning disc and a
mechanical counter display. This type of meter operates by counting the revolutions of a metal disc that rotates at a
speed proportional to the power drawn through the main fuse box. Nearby coils spin the disc by inducing eddy
currents and a force proportional to the instantaneous current and voltage. A permanent magnet exerts a damping
force on the disc, stopping its spin after power has been removed. This class of meters has a number of limitations
that has made it grossly irrelevant for use in smart energy initiative environment which include but not limited to its
degree of accuracy.
There are many methods of error correction in digital electricity meters which are usually based on the
known methods of A/D converters error correction, [5]. Most of these methods use software correction based on
calibration process. While in digital electricity meter, percentage error could be as low as 0.01%, in analogue
meters it is usually above 0.05%.
Secondly, the orientation problem associated with electromechanical energy meter is completely a nonissue
in a digital energy meter. Hence installation is made easier. Thirdly, the user friendly display in the digital
meters makes energy reading from time to time very easy. The fourth and the most serious setback of the
electromechanical energy meter is its no-interface capability to external devices. This very set back is very serious in smart grid technology application.