Are some pins more suited for capsense reading?

[brza_3998571]

I am reading capsense on three sensors using the CY8CKIT-042. The sensors and the circuitry seem exactly the same on each. Two of them are giving readings of similar magnitude under the same conditions, but one of the sensors is giving reading of a lower magnitude under similar conditions. It seems that the only difference between the sensors are the pins that are being used. I am using P2[5], 2[4], and 2[3]. I think P2[5] is the one giving a weaker reading. I was wondering if some pins are more suited for capsense and whether this is expected behaviour.

[Vison_Zhang · Accepted solution]

For PSoC4A-M, PSoC4A-L and PSoC6 family parts which has big number of IOs and larger packages, the pins which located close to CSD block inside silicon is more suitable for CapSense using. For these parts when you assign pins for CapSense sensors in Creator, you will see some pins marked with green color(highly recommended pins) and some marked with yellow color (usable pins).

But for PSoC4200 family part (silicon on CY8CKIT-042 DVK), no such different, i think maybe sensor which connects to P2[5] has bigger cp than others, so the sensitivity is slightly lower. You can try to decrease modulation idac value of this channel to increase sensitivity.