I have a small application running on the FRDM-KL02Z dev board - all is well. App uses 10 or so IO, mostly configured as GPIO.
For our own board we move to 24 pin version of the chip.
On our own board, I can connect and download code over SWD, and code appears to be running - I get successful debug print output, and said output is dependent on timer running, so code and peripherals are obviously running OK.
I have, however, no GPIO activity at all. All GPIO defined as outputs appear to be sat around 0.3V, and inputs do not respond to changes.
All port settings appear to be OK.
I notice that on FRDM board that the centre pad is connected to 0V, whereas mine is not connected (there appears to be no reference to it at all in the datasheet - certainly searching for 'pad' or 'pin' does not find anything. Could this be related?
Any other reasons why I might have no GPIO but a running chip.