Hi camvo,
You'll need to manipulate the ATmega328 TWI (I2C) registers directly.
Have a plough through the Atmel data sheet - heavy going.
http://www.atmel.com/Images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet.pdf
good luck, it's like climbing Mt Everest ! ( I still think you'd be better off with a parallel DAC ;-) )
ATB
MM
You'll need to manipulate the ATmega328 TWI (I2C) registers directly.
Have a plough through the Atmel data sheet - heavy going.
http://www.atmel.com/Images/Atmel-8271-8-bit-AVR-Microcontroller-ATmega48A-48PA-88A-88PA-168A-168PA-328-328P_datasheet.pdf
good luck, it's like climbing Mt Everest ! ( I still think you'd be better off with a parallel DAC ;-) )
ATB
MM