I never got an answer as to why FreeMaster won't show a sample rate faster than ~1ms. I've tried both PDB and ISR reads and get a similar sample rate. I've recorded the data to file and it's no different.
I'm only reading a single ADC channel (I've also tried with 2 and no difference). I've tried with and without hardware averaging. FreeMaster won't connect when hardware averaging is set to 32 samples, but the rest show no difference that I can see.
The only thing that made a noticeable difference to me was changing the sample time down to 2 from around 15. That definitely made a small difference.
I know FreeMaster is capable of faster reading and I know the hardware is capable so it must be something I'm doing wrong in the setup. Any help will be greatly appreciated.
I'm using S32K144EVB and FreeMaster 3.0. I have fixed step size set to 0.00001 (also tried at 0.0001).
I'm feeding the ADC a 60Hz sine wave that has been rectified and is a few hundred millivolts peak.
PDB triggers every 0.1ms
No hardware averaging
Hardware averaging 8 samples
Changed ADC sample time from 15 down to 2 and saw a change.