I remember that some of the earlier revision XMegas didn't come with any useful ADC calibration in the signature row.
But what about the E5? I have an early 32E5 rev B, that only has 0x00 in ADCACAL0/1. Do I need to worry much about that (as in finding a more recently produced 32E5), or doesn't it matter?
Regarding the averaging feature of the ADC. Does anyone use it successfully?
I am trying to use it in signed singleended mode, but am getting some nasty discontinuous jumps (looks like sign reversals) at certain input values, when I try to average 16 samples or more. Is that a known problem? I can't find anything about it.
I am working on simplifying my setup, so I can test this further. I am currently using a rather noisy sensor, that isn't useful for repeatable tests.