Just started getting into Arduino programming in the hope of doing a bit of audio experimentation.
I've lashed up an 8 bit R2R DAC (20/10k) and I'm using PORTD to write to it. I can get audio out of it but it looks on the scope like it's just a single bit in action (it also sounds like it).
I've played around disconnecting the various output pins from the R2R ladder to try and work out what's going on and I can disconnect the 7 least significant bits without the audio changing at all which seems to confirm my one bit theory.
Thinking that maybe I'm not writing all the bits of the port correctly I hooked up LEDs to each bit and a button which stepped through the sample data so I could see the sample represented in binary on the LEDs. This worked fine so the data is getting to the port ok.
So now I'm confused! It would seem the software is doing its job and the data is reaching the output pins ok which leaves the R2R circuit. I've triple-checked this and it looks good (not sure how I could screw it up?!) so I really don't know what's going on!
Any ideas would be most gratefully received!