I've been testing the capsense functionality with the CY8C4045LQI-S412 MCU for mutual capacitance sensors with overlay spacers, but the in-house PCBs don't seem to offer the reliability we expect with a one time pre-calibration.
Among the possible workarounds for this problem, I was considering trying some sort of runtime calibration.
Now the PSoC4S family seems to not support runtime adaptive calibration automatically, according to some of the product tables in the cypress website.
I was wondering if some power-up and esporadic calibration for the capsense sensor could be done with the help of an external MCU connected to the PSoC, in order to program calibration data and get results back.
Basically some keys seem to work fine while others seem to fail most of the time, while the people running the calibration and initial test seem to find it ok. Cypress people has looked at the PCB and, while I can see that some of the capsense guidelines could have been followed a bit better, they seem not to find any issue with it.
You can use a host MCU and change the calibration parameters using SetParam API. You can read the raw counts and other sensor data using GetParam API.
Pls refer to component datasheet for more details on the API. I hope this helps.