I saw somewhere on the net a project for a DIY bench powersupply that had a microntroller driving a 16x2 display with voltage and current. I lost the link (was it italian?)
I realise that arduinos only have a 10bit A/D but close counts in most hobby meters like i want to build...
Any suggestions?
Is not difficult to measure a current usage, you can use a shunt resistor (0.15ohm for example with appropriate wattage) in series at the positive power line and measure the current usage on the heads of this in mV.
(sorry for my bad english, i hope you understand :()
While this will measure current it will only be able to be used if the absolute voltage on the power supply output is less than 5V. Otherwise you will damage the inputs pins on the arduino. There are methods to get rid of the standing voltage on top of the differential voltage you want to measure but it can get involved and complex and involve operational amplifiers.
You might be better using a liner transfer opto isolator.