Making a Raspberry Pi based I2C EEPROM Gang Programmer
The Software
Right now I am using the software I found at
https://www.richud.com/wiki/Rasberry_Pi_I2C_EEPROM_Program
but I may decide to write my own version later.
To summarize the excellent instructions from the Wiki:
You have to make sure that the following modules are loaded:
- snd-bcm2835
- i2c-bcm2708
- i2c-dev
The first two were already loaded on my Pi, but I did have load i2c-dev
I already i2c-bcm2708 commented out in /etc/modprobe.d/raspi-blacklist.conf, make sure it is commented out on your Pi
add a new file /etc/modprobe.d/i2c.conf with the following line in it:
options i2c_bcm2708 baudrate=400000
Add a couple of packages:
sudo apt-get install i2c-tools hexedit
Fetch, make and install https://darkswarm.org/eeprog-0.7.6-tear5.tar.gz as per the instructions on the Wiki, which has examples on how to use it.
I simply ssh into the gang programmer Pi, and invoke my gang programming script with
sudo ./blast.sh
For now, I just wrote a dead-simple shell script read each IC into X.bin (where X is the IC socket number), and compare
- programming all eight EEPROM’s with a “RoboPi.eeprom” image
- read each IC into X.bin (where X is the IC socket number) for later verification
- compareeach X.bin (X=0..7) to RoboPi.eeprom, and report bad eeprom burns
Any errors will be visible at the end of the batch programming run.
FYI, it takes just over 25 minutes to program the eight eeproms – 25 minutes that can be used to work on something else 🙂
Here is the blast.sh script I use:
#!/bin/sh # program all eight sockets echo "\nPROGRAMMING...\n" ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x50 ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x51 ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x52 ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x53 ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x54 ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x55 ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x56 ./eeprog -f -16 -i robopi.eeprom -w 0x00 -t 5 /dev/i2c-1 0x57 # read back all eight chips echo "\nREADING BACK...\n" ./eeprog -f -o 0.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x50 ./eeprog -f -o 1.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x51 ./eeprog -f -o 2.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x52 ./eeprog -f -o 3.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x53 ./eeprog -f -o 4.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x54 ./eeprog -f -o 5.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x55 ./eeprog -f -o 6.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x56 ./eeprog -f -o 7.bin -16 -r0x0000:0x8000 -t 5 /dev/i2c-1 0x57 # verify all eight chips echo "\nVERIFYING...\n" echo "\nif you get a message about any *.bin file having a difference" echo "then the eeprom in that socket failed to program, or is bad," echo "or is inserted the wrong way around.\n" cmp robopi.eeprom 0.bin cmp robopi.eeprom 1.bin cmp robopi.eeprom 2.bin cmp robopi.eeprom 3.bin cmp robopi.eeprom 4.bin cmp robopi.eeprom 5.bin cmp robopi.eeprom 6.bin cmp robopi.eeprom 7.bin
For now I run the script from the directory I have the eeprog binary in, however I will likely soon suid root it, and move it into /usr/bin
Future Improvements
Improved software
- faster burning time
- auto detection of EEPROM size
- “read socket 0” button
- “program” button that programs all sockets with last read image
Improved hardware
- ZIF sockets
- LED indicators for which LED is currently being programmed
- LED indicating “OK” or “ERROR” status for each IC socket
Conclusion
I accomplished what I set out to do – semi-automate batch eeprom programming for RoboPi by making a very inexpensive gang programmer for a total cost of <$60USD, far less than commercial gang programmers.
Granted, the commercial units are faster, can program more devices, but I saved a lot of money making a unit suited to my needs myself – and using a $20 Raspberry Pi Model A with open source software, adding a uSD card, WiFi stick, prototyping board and a handful of parts.
I probably won’t be able to stop myself from tinkering with it, and improving the programming speed and software, and if I do, I will update this article.
p.s.
I invite you to join the Mikronauts forums!
Article Index:
Related Links:
