i encountered some problems with the I2C Library.
I have checked it with your “I2CDemo” C# i changed 2 lines:
private Byte i2cEepromAddress = 0x57; ///< EEPROM Device address i2cHandle = i2c.I2c_Init("I2C3"); ///< get handle to I2C device
I connected a scope to the I2C3 and noticed, that the i2c.I2c_Read(i2cHandle, (IntPtr)for_Casting_Intptr_to_Byte, bufferLenght); function does not do anything on the bus.
In contrast to this i2c.I2c_Write(i2cHandle, (IntPtr)for_Casting_Intptr_to_Byte, eepromAddressWriteOffset); works and i can get a reading on the scope and the EEPROM also responds.
I also noticed the existing Topic: I2C3 bus on T30 module - Toradex Community
But unfortunately i can’t get it to work. Maybe something more has changed in the last years…
Have a nice Weekend,
Best regards, Stefan