Hi, I'm in the middle of designing an Arduino Uno shield and have a couple of questions about design conventions.
1) I'll be using every input/output pin on the Uno. I can't see any feasible reason why you'd want to stack another board on top. Is it the convention to still use stackable headers anyway? Nearly every shield I've seen uses stackable headers.
2) The R3 Uno has longer headers than the R2 and R1. I'm not using the extra pins (I don't even know what they actually do!). Is it generally the convention to use the R3 header lengths, even though I'm not using those pins?
3) I'm not going to be able to fit all the components within the Uno footprint. Are there any dos/don'ts about which ways I can extend the PCB?
cheers Paul :)