eProjects

MPLAB Code Configuration and Microchip Xpress board

2018-09-03T12:15:00.002-05:00

As I mentioned on my Blog post about Microchip's Get Launched workshop, after some time without using the latest versions of Microchip development tools, I was playing lately with MPLAB X and MCC, and learned few tricks at the Microchip workshop about how to quickly put together a simple embedded application on MPLAB X IDE and getting it running in a low cost evaluation board.

For this particular project I used one of Microchip Xpress Evaluation Boards and MikroElektronika's 7seg display Click Board (MIKROE-1201)

This is a very simple project to show a two digit decimal counter on the seven segment displays. If you have MPLAB X and the MCC plugin properly installed it will take only few minutes to get it up and running. I will show you step by step how to make it happen.

While the Microchip Xpress Evaluation board has been initially designed to showcase the MPLAB Xpress online IDE, it can also be used with with the standalone MPLAB X on your computer but you will program it in a different way than other development boards, I will show you how.

This particular board has a QFN28 PIC16F18855 8-bit MCU with 8KB FLASH memory and 1KB RAM, and maximum clock speed of 32MHz. The Xpress board does not have an external crystal for the main clock and uses the high-precision internal oscillator. Connected to the PIC there are 5 LEDs, one push-button and a 10K potentiometer and as a bonus a EMC1001 temperature sensor. And obviously also wired to the PIC the pair of female headers for the mikroBUS™ so we can attach the seven segment display or other Click Board™.

Power is sourced from the microUSB connector, USB communication and programming is implemented using a PIC18LF25K50. The board includes a MCP1703 small LDO to step down the USB +5V to +3.3V.

The MikroElektronika 7seg Click Board™ has two standard JS-5213A common cathode single digit seven segment and decimal point displays, wired to a pair of SN74HC595 8-bit shift registers. In this board the displays are not multiplexed and driven in parallel from the MCU. The Click Board™ will take serial data to fill the registers to set the state of each output that drives all the segments and decimal points. The trick here is how to put together the stream of bits to show up the correct numbers on each digit, but don't worry here is where MCC is very helpful, the code is already there!

OK lets start putting the project together, launch MPLAB X IDE. Notice that on the top icon bar you will see MCC in blue, if you have it grayed out you must install the MCC plug-in.

Open a New Project and first select the correct target device, in our case the PIC16F188855.

Now we need to select which tool are we using to program the board. As I mentioned before since this board does not have a debugger we will select "Simulator" on the Hardware Tools tree.

Now we select the compiler. While I've both versions of XC8 I used v1.45 on this project originally before I installed v2.00. Now if you use v.200 be aware that there is a little bug, the workaround for now is to select ANSI C 90 standard.

After we complete setting up all the project properties we saved it.

This setup process creates the entire project structure and sets the correct parameters but take in account that there is not a line of code in the project yet! That's where MCC comes to play, so click on the MCC icon to make the magic happen.

Depending on how fast your PC is, it make take an instant to load the plug-in and additional menus associated with it. You will notice a new tab on the top left window labeled "Resource Management (MCC)" This tab will show various windows on the left, by default on top you will see the Project Resources and below it Device Resources.

On the Device Resources window we'll navigate to one of the last options showing "Mikro-E Clicks" open that menu tree and you will see a sub-tree with all the click boards currently supported by MCC organized by type. Then lets look at Display, and there! the LED7seg is listed as supported, double click on it.

We are not done yet since we need to tell MCC the particular configuration we have for this board and how each of the signals are assigned to the GPIO pins on the MCU.
You will see that on the main top right window now you have all the information and configuration associated with the LED7seg click board, including a picture of it and a direct link to the MikroElektronika product page.

On the bottom Output Window a new tab will appear with the Pin Manager Grid View.

Be aware that the default pin assignment may not be correct for the current Xpress board we are using, so we have some work to do. So take a look at the documentation or silkscreen on the 7seg click board and how it matches the GPIO signals on the Xpress board (RB0, RB1, etc.)

Also in the Project Resources window (top left) look for System->Pin Module and double check that your pin assignments and direction are correct. You will notice that MCC already assigned custom names for each of the signals.

After you are done just click on the Generate tab next to Project Resources.

Now if you go back to the Projects tab and look at the files tree, you will find that MCC populated the tree with all the files needed for the project. Are we there yet? Nope but close, we need to write two lines of code since what we get from MCC is the framework and an example. So look for these two files main.c and LED7Seg_example.h.

The files generated by MCC include all the code needed to drive and communicate with the 7seg click board, and includes an example about how to use this code, but the example is not yet used by our main program.

Then if you open the file, you will find what is the function we have to call from the main program to execute the example, in this case LED7Seg_example(void) so we'll add the call on the main while loop on main.c (remember to remove the void).

And since we are calling a function that has not been pre-defined we need to include the header file also on main.c.

Save all files, and click now on the Clean and Build Main Project top Icon menu, this will compile and generate the output binary file to be programmed on the Xpress board. As you can see the process on my machine took 8 seconds !!

Now it is time to program the board. If you didn't have it previously connected to your PCB via the microUSB cable, you can do it now. You will notice that the Xpress board will present a remote USB drive on your PC, in my case XPRESS(K:). If you open a file explorer window on it you will find a README.HTM file which is just a redirect to the Xpress board product page on Microchip's website.

Then on a file explorer window find your project files, MPLAB X IDE generates various directories, one of them is dist where you find the default production image. On that directory you will see the .hex file we need, in my case based on the project name I defined is Xpress-7Seg.X.production.hex, just copy and paste that file to the remote USB drive from the Xpress board and you will see that almost instantly the PIC18 programs the PIC16 and starts to run the program. You should see a decimal counter on the LED displays going up in intervals of one second.

That's it !!

While this project is very simple, there are other more complex that can be put together using MCC, but this is a great start to have something easy running quickly so you can learn the ropes.

I will be posting more projects soon, showing how to use other Microchip Development boards, some I designed and produced myself, and various MikroElektronika Click Boards.

Happy Hacking

Cheers
Jorge

PocketBeagle - How to increase root filesystem size

2018-06-20T18:13:00.001-05:00

If you are reading this, probably you already created your microSD card for the PocketBeagle which is recommended to be 4GB or bigger. But, regardless of the size of the microSD card you used the system image that got written on it has a fixed size that is most probably less than the total capacity of the card.

In my case, I used a 16GB microSD card, lets see how much is used …

debian@beaglebone:~$ df -v

Filesystem 1K-blocks Used Available Use% Mounted on

udev 220048 0 220048 0% /dev

tmpfs 49624 5592 44032 12% /run

/dev/mmcblk0p1 3357264 1659656 1507352 53% /

tmpfs 248112 0 248112 0% /dev/shm

tmpfs 5120 0 5120 0% /run/lock

tmpfs 248112 0 248112 0% /sys/fs/cgroup

tmpfs 49620 0 49620 0% /run/user/1000

As you can see the total size of the root file system is about 3.3GB and 53% is already used !

Then, how can you increase the size to use the total available capacity on the microSD card ?

The process is similar on other BeagleBoards and actually on many Linux distributions, on the PocketBeagle is very simple since there is only one “memory block” device /dev/mmcbkl0

debian@beaglebone:~$ ls -l /dev/mmc*

brw-rw---- 1 root disk 179, 0 Mar 5 07:12 /dev/mmcblk0

brw-rw---- 1 root disk 179, 1 Mar 5 07:12 /dev/mmcblk0p1

For the next few operations you will have to become the superuser (root,) instead of having to enter each command preceded by sudo, you can just do sudo -I which will give you the shell in root mode

debian@beaglebone:~$ sudo -i

We trust you have received the usual lecture from the local System

Administrator. It usually boils down to these three things:

#1) Respect the privacy of others.

#2) Think before you type.

#3) With great power comes great responsibility.

[sudo] password for debian:

root@beaglebone:~#

Notice that after entering the password now the command prompt changed from $ to #, you are now in superuser mode.

To increase the size of the partition and filesystem, first we’ll have to check the partition table and delete the current partition (don’t worry it does not delete the contents) and create a new partition with the new size.

root@beaglebone:~# fdisk /dev/mmcblk0

Welcome to fdisk (util-linux 2.29.2).

Changes will remain in memory only, until you decide to write them.

Be careful before using the write command.

Command (m for help): p

Disk /dev/mmcblk0: 14.9 GiB, 15931539456 bytes, 31116288 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x0736b542

Device Boot Start End Sectors Size Id Type

/dev/mmcblk0p1 * 8192 6963199 6955008 3.3G 83 Linux

Command (m for help):

Take note on with sector the partition says it starts, in this case 8192.

Now we will delete the existing partition and create a new one starting at the same sector but we’ll change where it ends, you can choose a smaller number than the total available sectors but I will chose the default which will give me all the available space on the current microSD card

Command (m for help): d

Selected partition 1

Partition 1 has been deleted.

Command (m for help): n

Partition type

p primary (0 primary, 0 extended, 4 free)

e extended (container for logical partitions)

Select (default p): p

Partition number (1-4, default 1): 1

First sector (2048-31116287, default 2048): 8192

Last sector, +sectors or +size{K,M,G,T,P} (8192-31116287, default 31116287):

Created a new partition 1 of type 'Linux' and of size 14.9 GiB.

Partition #1 contains a ext4 signature.

Do you want to remove the signature? [Y]es/[N]o: n

Command (m for help):

Notice that it now says the size of the Linux partition is 14.9 GiB !

No need to delete the signature, but we have not written yet the new partition table on the microSD card, we can double check the new parameters printing the new partition table

Command (m for help): p

Disk /dev/mmcblk0: 14.9 GiB, 15931539456 bytes, 31116288 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: dos

Disk identifier: 0x0736b542

Device Boot Start End Sectors Size Id Type

/dev/mmcblk0p1 8192 31116287 31108096 14.9G 83 Linux

What we want, all the available space on the microSD card as the Linux partition, then we are ready to write the table

Command (m for help): w

The partition table has been altered.

Calling ioctl() to re-read partition table.

Re-reading the partition table failed.: Device or resource busy

The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8).

As soon as we wrote the new partition the Linux kernel detects that it has changed and we’ll have to reboot so it can load the new table

root@beaglebone:~# reboot

You will obviously lose your connection to the board if you are connected via ssh, then wait for the board to reboot then restart the connection, login and become root with sudo -i

debian@192.168.7.2's password:

Linux beaglebone 4.9.82-ti-r102 #1 SMP PREEMPT Thu Feb 22 01:16:12 UTC 2018 armv7l

The programs included with the Debian GNU/Linux system are free software;

the exact distribution terms for each program are described in the

individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent

permitted by applicable law.

Last login: Mon Mar 5 07:31:39 2018 from 192.168.7.1

debian@beaglebone:~$ sudo -i

[sudo] password for debian:

root@beaglebone:~#

Before you do anything else we need to finish the process by extending the size of the filesystem with resize2fs, we’ll use the device that points to the first partition /dev/mmcblk0p1

root@beaglebone:~# resize2fs /dev/mmcblk0p1

resize2fs 1.43.4 (31-Jan-2017)

Filesystem at /dev/mmcblk0p1 is mounted on /; on-line resizing required

old_desc_blocks = 1, new_desc_blocks = 1

The filesystem on /dev/mmcblk0p1 is now 3888512 (4k) blocks long.

Let’s check then how much space we have now

root@beaglebone:~# df -v

Filesystem 1K-blocks Used Available Use% Mounted on

udev 220048 0 220048 0% /dev

tmpfs 49624 4960 44664 10% /run

/dev/mmcblk0p1 15247576 1662340 12914392 12% /

tmpfs 248112 0 248112 0% /dev/shm

tmpfs 5120 0 5120 0% /run/lock

tmpfs 248112 0 248112 0% /sys/fs/cgroup

tmpfs 49620 0 49620 0% /run/user/1000

There you go, now we have all the available space on the microSD card and we have only 12% used, enough to download some updates/upgrades and packages for development.

Essentially the same process is used to increase the size of any Linux partition but you must be very careful if you have more than one partition on the table since they can’t overlap and by changing the table and resizing the filesystems you may lose the data if not done properly.

So, what’s next ? Connecting to the Internet ? why not ?

How to coming soon !

Cheers

Jorge

Raspberry Pi - ECN001 Hardware Mod

2018-05-23T21:24:00.000-05:00

Update 5/23/18:
I published this article several years ago. No doubt many of the links and references are now outdated. Just keeping it here to preserve the history of some blog entries.

If you are one of the early buyers of the Raspberry Pi board (Rpi), you most probably have the first produced version that includes a Rev 1.0 printed circuit board (PCB) and polyfuses for powering USB devices, which I explained on my review of the Rpi has been the source of issues for many users, then after many reports, and users "shorting" the polyfuses, and additional testing, the Raspberry Pi Foundation (RPF) finally decided to issue a change in the assembly process (that was numbered ECN0001) which replaced the polyfuses by 0 ohm resistors and included another fix for the HDMI video interface.

How do you find what version of the board do you have ?

If your Rpi has two mounting holes, it is a Rev 2.0 PCB, then this hardware mod does not apply to your board.

If right next to the USB dual host connector you see two small green rectangles with a "14" marking on them, you have the very first production version with the Rev 1.0 PCB and polyfuses, then you can apply (at your own risk) this hardware mod to your board to match the changes introduced with ECN0001.

If instead of the small green parts you see black parts with the "0" or "000" markings, you have the second production version with the Rev 1.0 PCB and the ECN0001 already applied, then you don't need to apply this mod, but you still have the option to add heatsinks as I explain later.

If you already have Raspbian Linux running on your Rpi, you can check the contents of the /proc/cpuinfo file:

root@raspi:/# cat /proc/cpuinfo
Processor : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS : 697.95
Features : swp half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xb76
CPU revision : 7

Hardware : BCM2708
Revision : 0002
Serial : 0000000000001

The line showing the Revision number also tells you what version of the board you have according to the following table:

* Be aware that the first batch of Rev 2.0 with 512MB RAM, the Revision code was not properly programmed on the SoC and will show code 5, but after you perform the first update via rpi-update the code will be corrected to "f"

The ECN001 mod includes essentially two changes, but there is another recommendation about adding heatsinks to reduce thermal issues due to another problem for which there is no simple workaround on the Rev 1.0 PCB.

1- Replace Polyfuses

Locate the two polyfuses (F1 and F2) next to the USB host connector and carefully with a hot air rework station or solder wick remove the two polyfuses and clean the circuit board pads. You can use a piece of wire, but the most elegant way to match the ECN0001 version is to solder a pair of 0 ohm surface mount resistors in place of the polyfuses. In my case I used size 2512.

2- Remove D14 protection diode

Another of the issues reported with the first Rpi version has to do with the CEC (Consumer Electronics Control) connection on the HDMI video port. The cathode of this diode is wrongly connected to the +3V3 power line on the Rpi, which for some CEC compatible displays may create problems. The quick fix included on ECN0001 simply consists on removing this diode that is on the bottom side of the board right under the HDMI connector.

3- Add heatsinks at least to the SoC and LAN9512 controller (optional)

The Rpi uses the SMSC LAN9512 Ethernet controller and dual USB hub for its wired Ethernet interface and two USB host ports. This controller has an internal 1.8V voltage regulator, the output of this regulator is exposed on two pins where filter capacitors must be connected. The first version of the Rpi has these two pins erroneously connected to the main 1.8V power rail, which powers a section of the BMC2835/SDRAM stack. Many users reported that the temperature on the LAN9512 integrated circuit seemed to be much higher than normal, and thermal pictures of heat distribution were posted on line showing where major sources of heat were located.

One of the side effects of this erroneous connection is that the rest of the circuit hanging from the 1.8V power rail could be draining this power from the LAN9512 internal regulator, hence increasing its temperature.

Some users attempted to fix this problem by lifting the pins from the LAN9512, but still the connection or addition of extra filter capacitors were required. Anyway this issue was not catastrophic since the LAN9512 seems to be able to handle the extra load on those pins, and there is no conclusive evidence that the increased heat on the part was the potential source of malfunction. But this one is one of the issues that required a new version of the PCB.

Also, it is possible to "overclock" the BCM2835 for some extra performance, then also another side effect of overclocking is additional heat dissipation.

While is not mandatory and is hard to tell how the additional heat will affect the long term performance and durability of each part, it does not hurt to provide some additional means for heat dissipation.

Many users, myself included, opted for adding heatsinks for the LAN9512, the BCM2835/SDRAM PoP stack, and optionally the 3.3V RG3 voltage regulator.

I found a nice 12x13mm copper heatsinks on eBay that fit perfectly well on the BCM2835 SoC, and smaller ones from SparkFun for the LAN9512 and RG2 voltage regulator.

If you are planning to add the heatsinks I'd recommend you also get some extra double sided thermal tape.

Happy Hacking
Jorge

Update in progress ....

2018-05-20T18:05:00.000-05:00

Many years ago I started using these Blogs to record and to share what I learned from my R&D work in technology particularly Digital Electronics or Embedded Design.

Also one of my hobbies has been what may be called "Retrocomputing" sort of having a little fun with old computers, some electronics tools and gadgets.

Due to time constraint I sort of abandoned the practice of writing new articles and updating these Blogs. Well I decided that it is time to get back and refresh this corner on the websphere reorganizing these pages and getting back into the habit to write new articles and keep this updated.

To have the content somehow organized I will keep three associated but specifically focused Blogs.

Technology, Electronics, Reviews and Geek Gossip
I will post here general articles, reviews of parts, components, systems, personal experiences, etc
Short circuits, blue smoke, and a collection of DIY projects, experiments, tips and tricks in electronics (this page)
I will dedicate this one to specific projects I put together
ReTr0ByTeS
A Blog about retrocumputing projects, old computers and electronic gadgets

Some of these pages had some previous articles, some of them I put them in draft mode so I can check and update their content and republish.

I continue to generate a daily digital News Paper called Short Circuit that is generated automatically from various feeds I provide. I will also be updating those sources for more rich contact.

To those that have been writing me asking about old projects and when I'd be back... well this is the answer :-)

Hope you enjoy the content and feel free to provide your comments and contact me

Cheers
Jorge

Android APC Board has arrived

2012-08-09T07:53:00.000-05:00

Yet another ARM based board has arrived. This is the APC board from VIA which features a 800MHz Wondermedia WM8750 SoC (System on Chip) with an ARM1176JZF embedded core. The board has both HDMI and VGA video interfaces, 10/100 Ethernet, four USB 2.0 ports, audio in/out jacks and a microSD socket.

RAM is 512MB DDR3 and there is 2GB of NAND FLASH memory so there is no need of an external memory card with the Operating System which by default is Android 2.3 that comes pre-installed.

First impression out of the box and first boot, so far so good, I did connect it to my Samsung monitor via the VGA interface, small mouse and keyboard, hooked up to my lab network, powered it (power supply is included) and it took Android less than 10 seconds to boot.

There are not that many applications pre-installed, you can't install them directly from Google's play, but there is plenty of 3rd party sites with Android Apps that seem to work fine, more about it soon.

Take in account that this is a platform that is still under development and that this is the very first batch of boards made.

Didn't do much with the Web browser App included in the pre-installed image, but did try the YouTube App playing a trailer of Skyfall and it was flawless with great audio quality using earphones.

Here is a video of Rich Brown's talk at TED about the $49 PC.

More about it coming out of the lab soon ...

Cheers
Jorge

The Raspberry Pi - Finally

2012-07-22T14:25:00.000-05:00

On February 29th 2012, I was awake and anxiously waiting for the clock to hit the 6:00AM GMT time mark. After a long wait the day to be able to place an order for the famous and over hyped Raspberry Pi was arriving, I had already created my account on the RaspberryPi.com store and was happy to soon become the owner of one (or two) of the 10,000 boards that were being manufactured as the first production run for developers.

It is 6:00AM !! Big Surprise, instead of launching the sale directly, the folks from the Raspberry Pi Foundation (RPF) put together a deal with two major electronics distributors based in the UK, Farnell and RS Electronics. And that's not all, the boards are not available yet, they are still in production in China. But I was not a lonely geek trying to find how to place my order, there were a couple of thousand souls trying to do the same, so we DOSsed the distrubutor's websites that were not ready to take the orders, some of their affiliated sites overseas (like Newark) didn't have a part number for it, and there was a lot of confusion about price and shipping costs. This was just the start of a growing list of mishaps by RPF that I'll not cover here.

Finally after several hours trying and thanks to a fellow engineer that tweeted the right part number I was able to place an order for two units with Newark. Given that this was sort of a short run production there was a limitation of one unit, so I expected to have at least one in the next few days or weeks.

Time goes by, boards don't get shipped, alas !!!, the assembly house in China screwed up and populated the boards with the wrong RJ45 connector for the Ethernet interface !! more delays ... Ohhh, do the boards have CE and FCC certification and have been tested for hazardous materials asked the distributors ... huh?, more delays, and mixed with misinformation, confusing messages from RPF, frustrated people being kicked and banned from their Blog and forum (me included), and goes on. But after all the first board arrived by the end of May.

So what is the Raspberry Pi ?

The Raspberry Pi or Rpi, it is a small circuit board, about the size of a credit card with a Graphics Processor Unit with RAM memory on top (called PoP - Package on Package), an Ethernet controller with an integrated two port USB hub and various support components like voltage regulators, etc, to make the board work.

After many of us asking for them RPF made public the full schematics for it.

The GPU is a Broadcom BCM2835 System On Chip (SoC) that contains an ARM11 core running at 700MHz, and a Videocore 4 graphics processing unit, and there is a 256MB SDRAM from Samsung or Hynix.

For mass storage there is a socket on the bottom side of the board that fits a SD Memory Card, composite and HDMI video outputs, a rudimentary PCM stero audio ouput, and for the model B two USB ports and one Ethernet port implemented with SMSC LAN9512 single-chip Ethernet controller and USB 2.0 hub.

The following diagram made by Paul Beech shows what is on the board.

Additional details about the hardware can be found on the eLinux Wiki Rpi Hardware page.

What about software ?

From the get go the Rpi was intended to run a customized version of embedded Linux, or eLinux, there are several distros under work like Debian, Arch Linux ARM, Fedora Remix, QtonPI, and Raspbian the optimized version of Debian for the Rpi.

Disk images for the SD memory card (minimum recommended size is 4GB) of some of these distros are available at the RPF download page.

Take in account that this is still a work in progress, so some of the distros like Raspbian are based on betas like "wheezy" for Debian.

Here is a screen picture of X-windows running on the Rpi with 1920x1080 resolution. One of the windows shows the Scratch programming interface that has been created by MIT as a programming and learning language for young kids.

Where it came from ?

The Rpi is the brain child of a group of scientists from the UK, that were interested to revive some of the spirit of the old personal microcomputers like the BBC Micro, Commodore 64, Sinclair ZX, and many others like that from the 70's & 80's, that provide a very economic and simple computing platform for kids to explore computer science and learn the basics of programming.

One of the alpha prototypes and proof of concept was developed by Broadcom and later modified by Norcott Technologies to reduce the size and number of components to minimize costs. Unfortunately in the process some design decisions were made without the open participation of the community, like using a micro USB connector to feed power from cellphone chargers, what was perceived a cheap solution but is being one of the major problems with the current version.

After RPF made the deal with the electronics distributors, they took over production of the boards that are being assembled at some unknown factory in China at apparently at a rate of 4,000 a day.

How much it costs ? Is it worth to have ?

The RPF keeps promoting it with their site motto "An ARM GNU/Linux box for $25", but this statement is quite misleading.

First is not a box, it does not run Linux but a reduced version of it for embedded systems, if you factor in that you will need a power supply, a SD card, a keyboard, a mouse, and eventually a monitor with the HDMI interface and cable, it is much more than just $25, which by the way is the price for the model A that is not available yet.

If you are geek enough, have time and money to spent on it, even with some of the technical issues that are surfacing, it is still a cool and cheap gadget to experiment with embedded Linux. My interest is to see if it could be used as eLinux based small controller for other systems like home automation, alarm systems, energy management, etc.

If you are looking for a video streamer or game box, like many of the early enthusiasts that showed up on the RPi forum, I'll recommend you better get something like a Roku 2 box that is based on the same GPU and will provide you instant satisfaction.

Also be aware that you may have to wait 5-6 weeks to get yours.

I'll be posting more articles with a more detailed technical reviews, and share some of the projects I'll be working on with the Rpi.

For more information you can visit

Happy Hacking
Jorge

Yet Another PIC32 Proto Board

2011-10-22T09:08:00.000-05:00

Over the past few months I've been doing some developments and research based on Microchip's PIC32MX 32-bits Microcontroller product line. Time to time I have the need to do some hardware and firmware verification before I commit a final design on a pcb, I'm a prototype maniac.

Searching on eBay for TQFP-100 adapters I found this one from some folks in Thailand that is not just a plain adapter. It is tailored for dsPIC, PIC24 and PIC32 parts.

What is special about this one is that it is not just an adapter, as you will see on the other pictures below, on the bottom it includes the pads for several of the support components (decoupling capacitors, VCORE caps, etc.) and a header for the ICSP (In Circuit Serial Programming) interface to get a PIC32 up and running very easily.

You can get this adapter for less than U$S 2, and taking advantage of Microchip's excellent sample program you can get free samples of several of the PIC32MX family parts. I went ahead and dropped a PIC32MX795F512L-80I/PF on it.

Some folks may feel intimidated about soldering a 0.5mm pitch100-pin surface mount chip, don't be so, as you give it a try you will find that sometimes prototyping with surface mounted components is easier, quicker, cleaner and more reliable than with the old through-hole parts.

So how do you solder this beast ? I'll show you.

First of all, you need the right tools, patience, a good solder iron with a thin tip (I have a Weller WESD51 station with the PES51 iron and a long canonical 1/64 tip (ETS), a good set of tweezers, a pair of magnified glasses or a microscope, and more patience.

First of all make sure the board is clean, use denatured or isopropyl alcohol to remove any grease, dust, etc. Put just a tiny bit of solder in one of the corner pads, I normally do it with the lower left corner. Position the PIC32 with the right orientation, double and triple check that you put it with pin 1 where it is supposed to be, don't get confused with the orientation of the PIC32 legend on the chip, you will see it rotated clockwise 90 degrees, that's the right orientation !!

Using the tweezers or your fingers to hold the part in place making all the pins aligned with the pads, melt the solder on the corner pin so the pin gets soldered to the pad. Then add a little bit of solder on the opposite side and corner (upper left in my case, as shown on the picture). That will put the PIC32 in almost a fixed position so with your magnifying glass and/or microscope you can double check that all the pins align correctly with the pads before we move to the next step.

Then we are going to use a technique that consists on flooding all the pins with solder, that we will later clean up using a desoldering braid or wick. Do one side of the PIC32 at a time making a pause before moving to the next side so you don't overheat the PIC32.

The desoldering braid I use is a Pro Wick 1815-10F from my Texan friends of Techspray available from Mouser.

When you are done let it cool down before you start to clean each side with the desoldering braid, put the braid in parallel to the PIC32 side with enough braid to cover all the pins on that side, when you are ready put the iron on the braid (not the pins) as the braid heats up it will start sucking up all the excess solder from the pins, when you see that most of the solder has been removed remove the braid, don't let it cool down and attached to the pads or traces on the pcb. You need to be careful about not to damage the traces coming out of the pads or trying to remove the braid if some solder got it attached to the pads or traces, reheat the braid to make sure it is free of any hard connection.

Another great product I use from Techspray is a general purpose defluxer to remove all the flux left on the board by the solder. It is also available at Mouser and the product number is 1631-16S.

Once you are done removing the solder and cleaning the area you will find that you just soldered a 100-pin PIC32 microcontroller and it looks very neat !!

Now it is time to take care of the support components in the bottom of the adapter, in case you wonder about the values and what each one is for I put together a quick schematic showing how pins on this adapter are connected. Take in account that this is not a "generic" TQFP adapter, given that the Vss and Vdd pins are connected according to the dsPIC33/PIC24/PIC32 pin outs, but be aware that the Analog Vdd (AVDD) pin and VBUS pin are not connected to Vdd. After adding the bottom components and headers I added a small piece of wire connecting AVDD to VDD, without that connection your PIC32 will not startup or be recognized by your ICD or REAL-ICE.

To solder the SMD parts I normally put a little bit a solder in one of the pads for each part, then with the tweezers position the part with one hand while with the iron heating the pad with the solder. TIme ago I put together a tutorial with some pictures showing how to deal with these parts.
You may have noticed that on the schematic I have one LED connected to RG15, looking from the bottom on the upper right you can see one of the leads of the LED soldered to the GND/Vss plane and the other which I later connected via a 330Ω limiting resistor to RG15 (Pin 1).

While I included as optional the crystal and load capacitors for it as an external source for the PIC32 main clock oscillator, I was planning just to use the internal clock. These are the particular configuration bits (for the MPLAB C32 Compiler) I used for this project:

#pragma config FPLLODIV = DIV_1, FPLLMUL = MUL_20, FPLLIDIV = DIV_2
#pragma config FWDTEN = OFF, FCKSM = CSECME, FPBDIV = DIV_1
#pragma config OSCIOFNC = ON, POSCMOD = OFF, FSOSCEN = OFF, FNOSC = FRCPLL
#pragma config CP = OFF, BWP = OFF, PWP = OFF

After finishing with the components on the bottom, adding the wire for AVDD and the status LED, I added the headers for each side and for the ICSP interface. Created a simple program to initialize the PIC32 and get the LED on RG15 blinking, applied power and voila the thing became alive !!

I've several other development boards and gadgets for development with the PIC32MX family, but I really like this simple one that has nothing besides the minimal support components and one LED connected to its pins.

Hope you find this article useful for your PIC32 projects, don't be afraid of soldering a TQFP-100, the worst that can happen is you get a wasted free sample and few bucks on parts.

Happy Prototyping !!

Cheers

Jorge

chipKIT PIC32MX based boards by Microchip and Digilent

2011-06-03T07:48:00.000-05:00

Well, after some anxious waiting the new chipKIT™ development boards finally arrived this week. I'm obviously talking about the chipKIT™ Uno32™ and the chipKIT™ Max232™ boards produced by Digilent and co-developed with Microchip.
First of all notice that chipKIT™ is a registered Trademark by Microchip Technology, Inc. (they seem to be very cautious to include the ™ everywhere.)

These boards feature Microchip's PIC32MX 32-bit microcontroller family and claim to be somehow "the first 32-bit microcontroller-based platforms that are compatible with existing Arduino™ hardware and software" (more about the compatibility thing later).

The boards are produced by Digilent, Inc., and they share the same high quality and detail I've seen on other development boards produced by them. No need to say that the new chipKIT™ platform has behind it the marketing machinery of Microchip, and that the development of this new platform seems to have been originated within the Academic Exchange group to meet the demand for a 32-bit solution requested by the hobbyist, academia and embedded engineering communities.

(Hey look !! Microchip even produced and uploaded a video on YouTube.)
Update: For some reason the original video has been removed from YouTube.

As you may probably know "Arduino™ is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software", and until now all Arduino™ hardware has been based on Atmel 8-bit microcontrollers.

Hmmm "open-source", that's sort of new territory for Microchip, and obviously generated some buzz when the first rumors about these boards hit the development community, where Microchip licensing terms for most of the "License Free" stuff they make available for download and use are very well known for not allowing you to share or redistribute any changes or contributions to their stuff, kind of totally opposed to the spirit of the Arduino community.

Ian Lesnet from Dangerous Prototypes had a great initiative to collect questions from the community to be asked during a phone interview with the people involved in the chipKIT™ platform development. Ian was very kind to make the recording of the interview available on-line, you can find the recording and an interesting exchange of comments on this thread of Dangerous Prototype's forum.

OK, how compatible are the new boards with the existing Arduino™ stuff ?.

First of all notice that we are talking about a completely different Microcontroller, that means you need a different compiler and integrate it with the development environment. What Microchip did ? (something they not let you do with their stuff) took the open-source Arduino™ IDE and modified it to include support for the PIC32MX and redistributed it renamed as MPIDE (for Multi Platform IDE) with what seems to be an open-source license.

The key question is if the existing Arduino™ libraries will fully work on the new platform and if Microchip adds new libraries to support the new features introduced by using the PIC32MX will also be open-source and freely modifiable and distributable.

There are some folks already testing how well the existing libraries work and doing some performance testing as related on this article at Hack a Day, and some pin compatibility analysis by the Rugged Circuits folks.

About the hardware, the fine letter says "footprint compatible", and the intention here is to have the same form factor and approximate pinout so you may be able to use many of the already existing Arduino™ shields, but keep in mind the the chipKIT™ boards are 3.3V and there may be some shields that require 5V, remember always to check the schematics and documentation of each particular shield to avoid the unpleasant blue smoke.

Now taking a quick look at the new boards, this is a quick and preliminary first look at them, I'll post more articles as I power them and start doing some developments and tests.

The chipKIT™ Uno32™

Inspired and "footprint compatible" with the Arduino™ UNO. It features a 64-pin PIC32MX320F128H 32-bit Microchip microcontroller with 128KB of internal FLASH program memory and 16KB RAM, instead of a Type-B as the original Arduino™ UNO it has a mini-USB connector for the serial interface to the FTDI USB-Serial converter.

One thing that bugs me being one of the nice features of the PIC32MX family that you can have a nice chunk of program memory, why for one more dollar they didn't populate the Uno32™ with a PIC32MXF340F512H that has 512KB of FLASH and 32KB of RAM? It will probably be the first mod on my board.

The chipKIT™ Max32™

Inspired and "footprint compatible" with the Arduino™ Mega2560. It features a 100-pin PIC32MX795F512L 32-bit Microchip microcontroller with 512KB of internal FLASH program memory and 128KB RAM.

One nice feature of this member of the PIC32MX family is that it includes an 10/100 Ethernet MAC module, it requires and external PHY chip for a 10/100BaseTX but Digilent said to expect an shield that will take advantage of the Ethernet and USB interfaces by July.

Both boards include direct access to the PIC32MX ICSP interface in case you need to program the PIC32MX directly. The boards are preprogrammed with a bootloader and the classic flashing LED demo. In case you wonder why the ICSP header pins are not in line read this tutorial article from SparkFun.

One nice change on the layout of the new boards is the position of the RESET button, as you can see on the pictures if you have a shield installed on top of the Arduino™ boards unless you have a hole on the shield it is almost impossible to hit the RESET button, the new chipKIT™ boards have it in one of the corners where even with a shield on top it makes the button accessible from the side.

I'll start playing with the boards and post additional articles. As Microchip, I took care to include the stinking TM mark on all references which they make explicitly clear that are trademarks of Microchip and just saying that other trademarks are from their respective holders blah blah blah without mentioning that Arduino™ is a registered trademark of the Arduino team.

Hope this incursion of Microchip in this arena brings a change of attitude and helps they learn from this experience and embrace some of the practices of the open-source community.

BTW, even when it is a registered trademark the boards and associated software are not "official" Microchip products so don't expect direct support from Microchip, if you need help visit the chipKIT Forum (how original !! they also registered the chipKIT.cc domain, well it goes in companion with the originality of the packaging too).

Some links to keep handy:

You can currently purchase the boars via Digilent or Microchip Direct, I'm sure there will be other distributors in the near future.

Looking forward to see the first batch of clones :-), hey it is open-source after all !!

Cheers
Jorge

Building the TCP/IP Demo for the PICNet1

2010-07-19T16:54:00.000-05:00

Update 5/23/18:
I published this article several years ago. No doubt many of the links and references are now outdated. Just keeping it here to preserve the history of some blog entries.

This article will show how to build the PICNet1 demo application firmware based on the Microchip TCP/IP Stack (v5.25).

The PICNet1 PIC18 Development Board lets you populate the U1 (40-pin) or U2 (28-pin) microcontroller sockets with various PIC18F devices, such as PIC18F2620 or PIC18F4685. Also on the U3 socket you can install different serial EEPROM such as the Microchip 25LC256 or 25LC1024 or any equivalent including FLASH memories that have the same pin out. The Ethernet controller on board is always a Microchip ENC28J60.

Given that the Microchip Software License Agreement does not allow the redistribution of the TCP/IP Stack source code, you MUST obtain your own copy directly from Microchip and accept the terms of the applicable License Agreement.

There are some specific files from the Microchip TCP/IP Stack source code that need to be customized for this particular hardware configuration and application. I arrived to an agreement with Microchip where I can distribute the modified files in a separate directory leaving the original files untouched in their original directories. Those files that are a modified or customized version of the original files from the Microchip TCP/IP Stack distribution will include the following legend and a brief explanation about what has been modified from the original version.

This module is part of the original distribution of the Microchip TCP/IP Stack, and this modified local copy is included only to let you build a binary image for this specific hardware. To be able to create the binary image you MUST download the Microchip TCP/IP Stack directly from Microchip's website and accept the terms of the applicable License Agreement. By using this file you implicitly accept the terms of Microchip's License Agreement which by no means gives you the right to redistribute this particular file in its source code form. For additional information refer to the Microchip License Agreement and if you have any questions please write to Microchip Technology Inc., 2355 W. Chandler Blvd., Chandler, AZ 85224-6199 USA. ATTN: Marketing.

Then before we start, here is the list of items you will need to be able to build the demo application firmware:

Microchip MPLAB IDE version 8.50 or later
Microchip MPLAB C18 Compiler for PIC18 devices version 3.34 or later
Microchip TCP/IP Stack v5.25 distributed with the Microchip Application Libraries v2010-04-28
LJCV PICNet1 Demo Application files (only available for customers that purchased PICNet1 boards, send a message to support@ljcv.net to receive information about how to obtain these files)

Directory Structure and files

The Microchip Applications Library gets normally installed in the directory named "Microchip Solutions", under this directory you will find many subdirectories that include the source code for different application library modules and demos.

The tree structure below, only shows the directories related to the TCP/IP Stack and its generic Demo Application.

Microchip Solutions Applications Library install directory

+- Microchip Main directory for Microchip Libraries source code

| |

| +-- Help Help files for Library modules and demos

| +-- Include General include headers files

| | +-- TCIP Stack Header files for TCP/IP Stack

| |

| +-- TCP IP Stack TCP/IP Stack source code

+- TCPIP Demo App Generic TCP/IP Stack Demo application source

code, configuration and project files

The structure below shows the directory tree of the files distributed by LJCV to build the binary image for the Demo Application for PICNet1 board.

+- PN1_Demo-vX.Y PICNet1 Demo application main directory with

| MPLAB project files

+-- bin Output directory for binary images

+-- include Demo application header and configuration files

+-- obj Temporary directory for objects

+-- src Demo application source code

+-- TCIP Stack Microchip TCP/IP modified modules source code

Here is the list and description of each of the files on each directory:

- Directory PN1_Demo-v2.0 (current version)

- PICNET1.mcp MPLAB IDE Project file to build image for PICNet1

- MPFSImg2.bin MPFS Image for HTTP v2 server demo pages

- README.TXT This file

- Directory bin Precompiled firmware images (Intel hex format)

- PICNET1_2620.hex Demo firmware compiled for PIC18F2620 (*)

- PICNET1_2680.hex Demo firmware compiled for PIC18F2680 (*)

- PICNET1_2682.hex Demo firmware compiled for PIC18F2682

- PICNET1_2685.hex Demo firmware compiled for PIC18F2685

- PICNET1_4620.hex Demo firmware compiled for PIC18F4620 (*)

- PICNET1_4680.hex Demo firmware compiled for PIC18F4680 (*)

- PICNET1_4682.hex Demo firmware compiled for PIC18F4682

- PICNET1_4685.hex Demo firmware compiled for PIC18F4685

(*) Given the program memory required for the Microchip TCP/IP Stack

demo, these images have been compiled with all optimziations enabled

All images have been compiled with support for a 25LC256 serial EEPROM.

- Directory include

- picnet1.h Hardware configuration definitions for PICNet1

- HardwareProfile.h Hardware configuration general definitions

- HTTPPrint.h Callback headers for custom HTTP application functions

- main.h Global definitions and variables

- mib.h Original headers for custom SNMP application

- misc.h Header file for miscelaneous support functions

- TCPIPConfig.h Customized TCP/IP Stack configuration headers

- Directory src

- CustomHTTPApp.c Customized source code for the HTTP v2 server demo

- main.c Source code for the main demo application

- misc.c Source code for miscelaneous support functions

Building the demo application

Once you have the Microchip Application Libraries and the development tools properly installed you can add the directories and files needed to build the PICNet1 Demo Application Firmware.

The project file PICNET1.mcp includes the required files on the project file lists.

Given that on the project files and options references to include headers and TCP/IP library modules are done using the "..\Microchip\xyz" path, the PN1_Demo-vX.Y must be copied to the same directory level as the "TCPIP Demo App" directory, under the "Microchip Solutions" directory or whatever directory was used to install the Microchip Application Libraries.

Once you have copied the files to the proper directory, on MPLAB IDE you must open the PICNET1.mcp project file, on the top menu bar select to build the "Release" version of the code, and select the proper target device that is installed on the PICNet1 MCU U1 or U2 sockets.

Take in account that because of the increase in size of the latest versions of the Microchip TCP/IP library, to be able to compile a version of code that includes the latest HTTP 2 server module, you will most probably need to enable the compiler optimizations to generate a binary image that fits on the PIC18F2620/4620 program memory.

Also double check that you are using "overlay" storage class and large code and data models (Project->Build Options->MPLAB C18), and that MPLAB IDE on the Directories tab the Library Search Path is set to the correct directory where the c018 libraries are located.

Be aware that not all the modules included with the original TCP/IP Stack Demo Application has been tested or compiled for the PICNet1 Board, some of these modules may require additional customization to work on this board.

After compiling and programming the binary image on the target device, if you connected a terminal or computer running a terminal emulator to the RS-232 interface (default configuration is 19200bps, N, 8, 1), after RESET you should see a series of informational messages like these:

PICNET1 Hardware Initialized, HW Config Ver.1.0, MCU = PIC18F4620

MPFS Initialized, Ver.2.1

PICNET1 Config loaded

Microchip TCP/IP Stack Ver.v5.25

MAC Address = 00:04:A3:00:00:20, IP Address = 169.254.1.1

PICNET1 Ready, FW Ver.2.0, Built Jul 19 2010-09:11:22

New IP Address = 169.254.1.1

New IP Address = 10.0.2.102

For additional information and documentation about the Microchip TCP/IP Stack refer to the Help file included in the Microchip Applications Libraries distribution, and for latest information and up to date instructions about how to build the demo firmware for the PICNEt1 board visit the product page at http://www.ljcv.net/picnet1/

Happy Networking

Jorge

Building the TCP/IP Demo for the eIP-10

2010-07-15T08:19:00.000-05:00

Update 5/23/18:
I published this article several years ago. No doubt many of the links and references are now outdated. Just keeping it here to preserve the history of some blog entries.

This article will show how to build the eIP-10/eIP-10+ demo application firmware based on the Microchip TCP/IP Stack (v5.25).

There are no major differences between the eIP-10 and eIP-10+ boards, in fact the printed circuit board is exactly the same one, the only differences are that on the eIP-10+ board the microcontroller is a PIC18F2685 instead of a PIC18F2620 and the serial EEPROM a 25LC1024 instead of a 25LC256; but you still need to separate projects to define the target device for each different microcontroller.

There are some specific files from the Microchip TCP/IP Stack source code that need to be customized for this particular hardware configuration and application.

I arrived to an agreement with Microchip where I can distribute the modified files in a separate directory leaving the original files untouched in their original directories. Those files that are a modified or customized version of the original files from the Microchip TCP/IP Stack distribution will include the following legend and a brief explanation about what has been modified from the original version.

Then before we start, here is the list of items you will need to be able to build the demo application firmware:

Microchip MPLAB IDE version 8.50 or later
Microchip MPLAB C18 Compiler for PIC18 devices version 3.34 or later
Microchip TCP/IP Stack v5.25 distributed with the Microchip Application Libraries v2010-04-28
LJCV eIP-10 Demo Application files (only available for customers that purchased eIP-10 or eIP-10+ boards, send a message to support@ljcv.net to receive information about how to obtain these files)

Directory Structure and files

The tree structure below, only shows the directories related to the TCP/IP Stack and its generic Demo Application.

Microchip Solutions Applications Library install directory

+- Microchip Main directory for Microchip Libraries source code

| |

| +-- Help Help files for Library modules and demos

| +-- Include General include headers files

| | +-- TCIP Stack Header files for TCP/IP Stack

| |

| +-- TCP IP Stack TCP/IP Stack source code

+- TCPIP Demo App Generic TCP/IP Stack Demo application source

code, configuration and project files

The structure below shows the directory tree of the files distributed by LJCV to build the binary image for the Demo Application for the eIP10 and eIP10+ boards.

+- EIP10_Demo-vX.Y eIP10 Demo application main directory with

| MPLAB project files

+-- bin Output directory for binary images

+-- include Demo application header and configuration files

+-- obj Temporary directory for objects

+-- src Demo application source code

+-- TCIP Stack Microchip TCP/IP modified modules source code

Here is the list and description of each of the files on each directory:

- Directory EIP10_Demo-v2.0 (current version)

- EIP10.mcp MPLAB IDE Project file to build image for eIP10

- EIP10P.mcp MPLAB IDE Project file to build image for eIP10+

- MPFS2.bin MPFS Image for HTTP v2 server demo pages

- MPFS.bin MPFS Image for legacy HTTP server demo pages

- README.TXT Instructions to build the demo application

- Directory bin Precompiled firmware images (Intel hex format)

- EIP10.hex Demo firmware compiled for the eIP10 with optimization

supporting the new HTTP2 server module

- EIP10_MPFS1.hex Demo firmware compiled for the eIP10 without

optimization and supporting the legacy HTTP and

FTP server

- EIP10P.hex Demo firmware compiled for the eIP10+ without

optimization and supporting the new HTTP2 server

- Directory include

- eip10.h Hardware config definitions for eIP10 and eIP10+

- HardwareProfile.h Hardware configuration general definitions

- HTTPPrint.h Callback headers for custom HTTP application functions

- main.h Global definitions and variables

- mib.h Original headers for custom SNMP application

- misc.h Header file for miscelaneous support functions

- TCPIPConfig.h Customized TCP/IP Stack configuration headers

- Directory src

- CustomHTTPApp.c Customized source code for the HTTP v2 server demo

- LegacyHTTPApp.c Customized source code for legacy HTTP server demo

- CustomSNMPApp.c Original source code for the SNMP application demo

- main.c Source code for the main demo application

- misc.c Source code for miscelaneous support functions

- Subdirectory src/TCPIP Stack

- SPIEPROM.c Customized version for the serial EEPROM driver code

- UART2TCPBridge.c Customized version for the UART to TCP Bridge code

Building the demo application

Once you have the Microchip Application Libraries and the development tools properly installed you can add the directories and files needed to build the eIP10 or eIP10+ Demo Application Firmware.

The main differences between the image generated for the eIP10 and the eIP10+ boards are, support for a different microcontroller, PIC18F2620 for the eIP10 and PIC18F2685 for the eIP10+, and support for the serial EEPROM driver 25LC256 for the eIP10 and 25LC1024 for the eIP10+.

Most of the base code for both boards is the same, then a separate distribution for each board is not required and instead the code includes a macro definition EIP10P on the MPLAB IDE project file for the eIP10+.

The two project files EIP10.mcp and EIP10P.mcp, include the required files on the project file lists and define the macro for conditional compilation accordingly.

Given that on the project files and options references to include headers and TCP/IP library modules are done using the "..\Microchip\xyz" path, the EIP10_Demo-vX.Y must be copied to the same directory level as the "TCPIP Demo App" directory, under the "Microchip Solutions" directory or whatever directory was used to install the Microchip Application Libraries.

Once you have copied the files to the proper directory, on MPLAB IDE you must open the EIP10.mcp or EIP10P.mcp project file depending on the board you are using, on the top menu bar select to build the "Release" version of the code, and verify that you have selected the proper target device, PIC18F2620 for the eIP10 and PIC18F2685 for the eIP10+.

Be aware that not all the modules included with the original TCP/IP Stack Demo Application have been tested or compiled for the eIP10 or eIP10+ boards, some of these modules may require additional customization to work on these boards.

For additional information and documentation about the Microchip TCP/IP Stack refer to the Help file included in the Microchip Applications Libraries distribution.

Happy Networking

Jorge

eip-24 and eip-24/100 Preview

2009-10-22T09:31:00.000-05:00

Update 5/23/18:

I published this article several years ago. No doubt many of the links and references are now outdated. Just keeping it here to preserve the history of some blog entries.

After few rounds of feedback from colleagues and debating with myself, I completed the final design for two new embedded TCP/IP boards.

The first batch of printed circuit boards are in the final steps of fabrication and I'll have them soon to complete assembly and testing.

Both boards will have a 16-bit Microchip PIC24HJ128GP202 as the main processor, same form factor and almost identical pcb layout, and same pin-outs.

The eip24 shown above will have a Microchip ENC28J60 10BaseT Ethernet Controller, a 16Mbit SPI Flash memory and a Microchip 25AA02E48 EEPROM with a unique Ethernet MAC Address.

The eip24-100 shown above will have aMicrochip ENC424J600 10/100BaseT Ethernet controller, a 32Mbit SPI Flash memory, and a Microchip 23K256 SPI RAM memory.

Both boards will also have three LEDs for heartbeat status indication or other use, and an RS232 transceiver for the serial interface.

On the drawing board and prototype bench I've right now a piggy-back board that will be compatible with both the eip24 and eip24-100 and that will have a 3x16 DOGM LCD, a microSD card socket, a temperature sensor, a 3.3V voltage regulator, some pushbuttons and a RJ11-6 for ICSP connection to an ICD2/3 or similar PIC programmer.

I'll post another article with additional details of the piggy-back board and an update as soon as the final docs and the eip24 boards become available.

Now it's time to go back to work on the firmware for them that will essentially be based on Microchip's TCP/IP Stack v5.10.

Cheers,

Jorge

ENC424J600 - nic424 Board in production !!

2009-10-12T09:28:00.000-05:00

Update 5/23/18:

I published this article several years ago. No doubt many of the links and references are now outdated. Just keeping it here to preserve the history of some blog entries.

It took me a while but finally the nic424 boards featuring the new ENC424J600 Ethernet Controller from Microchip are in production and available for ordering.

I had the first batch of boards ready for sale but I wanted to expedite and improve the test and validation process, for it then I designed a small customized "tester" using a PIC24HJ128GP202 as the "brains" for it, taking also avdantage of the analog features to measure voltage and current for the device under test.

Given the similarities of the nic424 with the nic28 boards, and the fact that I had some extra space on the prototype pcb I was using, I allocated some space and added the test pins for the nic28.

Here is an ugly picture (well it's not supposed to be pretty since it's internal stuff) of the finished tester in action.

Connection to all the test points are implemented with retractable pogo-pins which are kept in alignment with a small layer of plexy-glass, once the board to test is in place four large hexagonal separator act as nuts to keep the board in place and apply pressure to the pogo-pins for optimal contact.

The PIC24HJ128 controls power to the device under test (DUT), and using the ADC module measures the supply voltage to the DUT and supply current using a four-leads current sense resistor that feeds the voltage differential over the resitor to an MCP6022 operational amplifier that connects to one of the analog inputs of the PIC24HJ.

The LCD displays the measured values, the DUT MAC Address and together with two push buttons on the side acts as the user interface for several options and parameters of the test firmware.
When the test is finished the firmware that uses the Microchip TCP/IP stack, generates a complete test report that as a dynamic web page.
If you are interested in additional information about this application or the nic424 feel free to contact me.

Regards
Jorge

Microchip ENC424J600 - Preliminary Tests

2009-08-21T07:26:00.000-05:00

Finally the printed circuit boards and all parts arrived and I've got some time to put together the first batch of nic424 boars featuring the new Microchip ENC424J600 Ethernet Controller.

Based on the firmware code distributed with the latest (v5.10) Microchip TCP/IP Stack I customized a MAC driver module specifically for the nic424 and started to run some preliminary tests.

To my surprise I didn't have any problems getting the board up and running on the first try.

To test the Ethernet controller I mounted the nic424 on a solderless prototype breadboard alongside a ProtoPIC28 board populated with a Microchip PIC24HJ128GP202 Microcontroller.

For this first set of tests I'm using the SPI interface with a clock speed of 10MHz and the PIC24HJ running at 80MHz clock speed.

I compiled the TCP/IP Stack with the drivers for the nic424 and only included the ICMP Server module and the TCP Performance Test module.

The first test consisted in sending ICMP ECHO Requests (pings) packets to the PIC24HJ + nic424 from a dual core Pentium machine with Linux running at 2.4GHz, and connecting the Linux server and the nic424 through a Cisco Catalyst C2950 Ethernet Switch.

The Cisco C2950 didn't have any problems negotiating 100Mbps and Full Duplex with the ENC424J600 so I started playing with the payload sizes of the ping packets, going from 32 bytes up to 512 bytes. For each test the Linux server sent over a million packets in flood ping mode, packet loss with all payload sizes was 0% and the TCP/IP Stack didn't hang or reset during the tests.

To have a comparative test, I replaced the nic424 with a nic28 using the Microchip ENC28J60 Ethernet Controller and ran the same tests.

The graph below shows the average Round Trip Time results of the tests with both Ethernet controllers, clearly the ENC424J600 even at the same SPI clock performs faster than the ENC28J60.
After running the ICMP tests, I ran the TCP Performance Test with both controllers. The configuration using the ENC28J60 reported 97,100 Bytes/sec when the configuration using the ENC424J600 reported 134,100 Bytes/sec.

I'm planning to run some additional tests to get some metrics for packets per second and bytes per second taken from the five minute averages computed by the Cisco switch.

I'll mount a nic424 on a PICtail+ prototype board and do some testing with different processors on a Microchip Explorer 16 development board, and also try different parallel interface modes and see how well the crypto engines included in the chip perform.

So far things look very good, average current for the ENC424J600 was consistent with the values shown in the datasheet, around 200mA and the chip does not get too hot.

Don't have a firm date yet but I'll soon make the nic424 available for purchase through the LJCV Electronics site.

Regards
Jorge

New 10/100 Mbps Ethernet Controller from Microchip

2009-08-03T06:24:00.000-05:00

About four years ago Microchip debuted in the ethernet controller market with the introduction of the smallest standalone ethernet controller, the ENC28J60.
While embedded application developers looking to add a networking interface to their designs had other options, the ENC28J60 became a very interesting alternative for many applications since it didn't require to use many I/O pins from the MCU to talk with the controller.
Just a few components, the RJ45 with integrated or external magnetics, a simple connection using the SPI interface and voila you were on the 'net courtesy of the free Microchip TCP/IP Stack.
Few months ago we started savoring and playing with samples of a new generation of ethernet controllers to be available from Microchip, the ENC424J600 and ENC624J600. Today, Microchip made the official announcement !!
While some hobbyists will not be extremely happy because the new parts will be only available in 44 and 64-pin TQFP and QFN packages the new controllers have many goodies we were all waiting for, such as:

Integrated MAC and PHY for 10/100BaseTX twisted pair ethernet
24 KB of RAM compared to 8K from the ENC28J60
How many times folks asked in the Microchip forum where to get the MAC address from ? Now it's on the chip !!, no more hassle you get the chip you have the address !!
We still get the simplicity of the SPI interface but on top of that now a multiple mode parallel interface
Integrated Security Engine on the chip to support RSA, MD5, Diffie-Hellman and SHA-1 computations
Available in two flavors, 44-pin (fewer parallel interface options) and 64-pin

If you can't control your anxiety to put your fingers on this new part and start playing with it, more good news, the 10/100Mbps Ethernet PICtail is available for purchase from Microchip.
In the past few weeks I've been working on a new network interface card similar to the nic28 I produced in the past for the ENC28J60. Just waiting for the first batch of pcbs to arrive and complete testing and documentation.
I'll soon post some pictures and specs for the new nic424 that will become available for purchase through LJCV Electronics.
Happy Networking !!!
Regards
Jorge

COG LCD Character Module with SPI Interface

2009-07-27T08:18:00.000-05:00

For some applications adding an alphanumeric display, particularly an LCD Character Module could be a plus, not only as a Human Machine Interface (HMI) but also as an output interface for device diagnostics and troubleshooting.

Nowadays Character Module LCDs are quite inexpensive, most of them use a parallel interface based old Hitachi HD44780 or its Samsung cousin KS0066 controllers.

You will also find some folks selling a Character Module LCD with an add-on serial interface or things like the Serial Enabled Backpack from Sparkfun.

On one of my projects I showed how to interface a regular Character Module using the SPI interface taking advantage of the Microchip MCP23S08 port extender.

I’ve been looking around for a while for a reasonable priced integrated solution, preferable with Chip On Glass Technology that does not take to much pcb real state.

To my satisfaction I recently found that the folks from Electronic Assembly in Germany started to produce the DOG-M LCD series that is exactly what I was looking for.

The DOG-M LCD display series, not only provide the classic parallel interface but they also offer using the same controller the SPI interface option, and guess what you can use them with +5V or +3.3V supply.

There are different variants including STN yellow/green, reflective, STN blue, FSTN positive and negative, some of which require a backlight, but EA also offer a nice collection of LED based backlighting with ultra thin construction.

The EA DOG-M display series is available from Mouser Electronics.

I’ll be using the 3 x 16 model for one of the products I’ve under development.

I'll soon post some pictures with the DOG-M displays in action.

Cheers

Jorge

From the 4004 to modern microcontrollers

2007-02-21T08:07:00.000-06:00

Since the introduction of the first logic gates ICs and the Intel 4004 and later the Motorola 6800, I’ve been always interested in digital electronics and microprocessors. I had a lot of fun with the legendary 4004 but I really learned a lot about microprocessors when I was able at school to put my hands in one Motorola MEK6800 D2 evaluation kit and later due my involvement with Texas Instruments a TMS9900 evaluation board.
It was an interesting challenge in those days to develop certain applications due the limitations in memory space and processor speed. I learned to program these antiques entering the code directly in a hexadecimal keyboard. I can still today recite parts of the 6800 instruction set.

No doubt that since the introduction of the 4004, microprocessor technology has evolved tremendously and even following Moore’s law I could have never imagined the computing power and features that we can find in today’s microprocessors.

But there was something that caught my interest couple of years ago and in which I’ve been working lately, microcontrollers.

While a microcontroller does not have the same feature set and processing power of modern microprocessors, they are very suitable for a vast number of applications and include many features and peripherals that may have required a large collection of integrated circuits in the past.

And they are everywhere!! If you drive a relative modern car, chances are very high that your car may have a dozen of them, many appliances today replaced electromechanical controls by microcontrollers, your garage door opener use them, and you may even find them in pregnancy test sticks.

I hope through this blog to share some of my experiences dealing with microcontrollers and related devices. Currently many of the projects I’m working on are based on microcontrollers from Microchip Technology, but I’ll include some posts about Atmel, Texas, Freescale and others.

Enjoy !!