Programming the EEPROM
To program the EEPROM of the extention board, dtparam=i2c_vc=on must be entered in /boot/config.txt.
Here is an example of my config.txt file.
The required software is installed (as root) using:
cd
git clone https://github.com/raspberrypi/hats.git
cd hats/eepromutils
make
git clone https://github.com/raspberrypi/hats.git
cd hats/eepromutils
make
Reading the EEPROM
this works with
./eepflash.sh -r -f=x.eep -t=24c32
This creates a file x.eep containing the contents of the EEPROM.
Creating the EEPROM file
./eepmake eeprom_settings_p4ex1.txt pi4ex1.eep
This then generates a binary file from our text file, which can be used for programming.
Flashing the EEPROM
./eepflash.sh -d=0 -w -f=pi4ex1.eep -t=24c32
This writes the previously created file to the EEPROM.
If this doesn't work, it may be due to the position of the Write Protect switch or jumper.