Python module to use a Raspberry Pi to read/write to EEPROM
This Python module will control a Raspberry Pi such that it drives a circuit to read and write to a parallel EEPROM such as a CAT28C65B or similar (13 address lines, 8 data lines, chip enable, output enable, write enable).
The circuit required is three chained counter chips to hold a 12-bit address on A0-A11 (tie A12 low (or high if you want to write to the upper half)) with a single increment line to the lower 4 bits, plus a reset line.
The program has to be run with root privileges to access the GPIO pins. Run on the Pi with sudo python eeprom.py --help
Or use interactively in a Python shell:
sudo python
>>> from writer import *
>>> find(0)
>>> dump()
incris the increment line to the lowest counter chipresetis the counter chips' reset lineledcan control an LED- The other connections are on the EEPROM chip
- The colours are for my tracking
| wire | Pi pin | port | purpose |
|---|---|---|---|
| red | 2 | 5V | |
| brown | 6 | GND | |
| orange | 3 | GPIO2 | incr |
| yellow | 5 | GPIO3 | reset |
| green | 7 | GPIO4 | WRITE |
| black1 | 11 | GPIO17 | READ |
| white1 | 13 | GPIO27 | D0 |
| grey1 | 15 | GPIO22 | D1 |
| blue1 | 12 | GPIO18 | D2 |
| purple1 | 16 | GPIO23 | D3 |
| purple2 | 24 | GPIO8 | D4 |
| blue2 | 26 | GPIO7 | D5 |
| grey2 | 23 | GPIO11 | D6 |
| white2 | 21 | GPIO9 | D7 |
| black2 | 19 | GPIO10 | led |