I am planning on building my own lab bench power supply which should be software controlled and have two outputs. I am considering using the ATMega2560 due to its large amount of I/O pins, but I don't know how to read/write analog voltages to/from the two outputs. I think that they need to be isolated if I wan't to hook them up in parallel for more current which means that I can't just connect them both directly to the microcontroller.
Am I right or can the two outputs share the negative ground rail and just have the positive rails regulated?
If they need to be isolated, how would I go about reading and writing analog voltages to them (setting and measuring output voltage/current)?