DAC attached to the I2C, but also want to use adc?

The project I'm currently working on required both signal generation and reading. Having an Arduino uno I purchased the 12 bit DAC from Adafruit that attached to the I2C lines (A4, A5). My problem then arises to how one switches between reading analogue values, and sending commands to the DAC. Is this even possible? If it is, is there a tutorial hiding somewhere that I cannot manage to find; where one switches between IC2 peripheral and ADC reading on an Arduino?

Thanks in advance :3

Is this even possible?

No. Once you use A4 & A5 for I2C it is not sensible to use those pins as analogue inputs with the I2C hardware still attached.

You don't use the Arduino's ADC commands to use the external DAC. If you wire up A4 and A5 to use the I2C digital protocol you can't access the ADC on those pins but there are others free.


I good solution would to be just get one of the adafruit’s I2C ADC modules and add it to the I2C bus you are using for your DAC. That way you gain four analog inputs for the two you lost by using I2C on the Uno. This gives you a better quality ADC with many features you might find useful.