EEPROM PMOD

Description

EEPROM PMOD This I2C PMOD provides a 1 Mbit serial EEPROM, using the M24M01 circuit by STMicroelectronics. DIP switches enable I2C pull-up resistors if needed, and change the I2C address between 0x50, 0x51, 0x52, and 0x54. Up to four modules can be chained for a total capacity of 4 Mbit (512 MBytes). Three Testpoints can be fitted for I2C bus troubleshooting. The PMOD has designs for Type-6 (I2C single row), and for the new Type-6A (I2C extended double row). The picture shows the Type-6A variant (engineering sample).

Schematic

EEPROM PMOD Schematics

PCB Gerber

EEPROM PMOD Github Repo

Example Code

RPi I2C discovery: First we set Reset and Int pins 'high' to enable circuit operation. From EEPROM module version 1.1, two additional 10K pull-up resistors (R28,29) have been fitted to auto-enable the circuit. The gpioset command is part of the 'gpiod' pin control program and library, installed with 'sudo apt install gpiod'.

pi@pi-ms05:~/pmod2rpi/pi-tca6424a $ gpioset gpiochip0 22=1
pi@pi-ms05:~/pmod2rpi/pi-tca6424a $ gpioset gpiochip0 27=1

Now we can see the IO expander circuit under address 0x22 (address pin = '1'), or 0x23 (address pin = '0').

pi@pi-ms05:~/pmod2rpi/pi-tca6424a $ i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- 22 -- -- -- -- -- -- -- -- -- -- -- -- --
...

RPi

EEPROM PMOD on RPi

EEPROM PMOD, connected to the PMOD2RPI interface board.