I2C with digital outputs

I need to drive a DAC from a Duemilanove, and I'm looking at using an I2C device (MAX517BCPA+). I know I can use analogue inputs 4 & 5 to drive it with the Wire library, but I can't afford to lose those inputs. Is there likely to be any problem using two digital outputs? I realise I'll probably have to write more code to handle the I2C protocol.

gutbag:

Is there likely to be any problem using two digital outputs?

No.

I realise I'll probably have to write more code to handle the I2C protocol.

You bet!

Don

I think you would be far better off getting a mega. Writing the code to implement I2C via bit-banging on digital pins would be a large project.

Mark

Or maybe add an I2C "port expander" or ADC to replace the "lost" pins, depending on what they're being used for.

Thanks for the replies. I think I'm going to use a 3-wire serial device instead. Is there a favourite 8-bit (or more) non-I2C DAC for use with Arduinos? It's to provide a CV output with a range of 0-5V.