Regarding how to check CSX mutual capacitance.

YuMa_1534086 · ‎Oct 30, 2019

Hello Cypress.

Is there API for calculating mutual capacitance(Cm)?

I think that CapSense_GetSensorCapacitance only calculates TX capacitance and RX capacitance separately.

CSD can calculate self capacitance(Cp).

It was possible to judge whether device could drive the sensor by checking obtained value.

If user uses CSX, how should they check mutual capacitance whether Cm is smaller than maximum value specified by device?

Below is calculation formula of CSX RawCount.

Cm is used in the CSX RawCount formula.

So it is necessary to know Cm in advance in order for CSX to output RawCount.

How does CSX calculate Cm before calculating RawCount?

Best Regards.

Yutaka Matsubara.

Hari · ‎Oct 30, 2019

We don't have an API that directly gives the mutual capacitance value. Please refer this KBA Mutual Capacitance Calculation of a CapSense Sensor Through Firmware - KBA222425 for details on how to calculate Cm for your design.

Thanks and regards

Hari

Re: Regarding how to check CSX mutual capacitance.