Capacitance sensing with nRF52 along with SD132

[Akram Karimi]

Hi, I need to measure the capacitance of few capacitors for which I am currently using 3-channel CAP1203 IC from microchip. However, I just came across the possibility of using nRF52 to measure capacitance directly: link text

Can anyone tell me: 1- What's the possible drawback of using nRF52 capability of sensing capacitance? 2- Is there any ready to use example for measuring capacitance using SD on nRF52?

Please note that I need SD132 for bluetooth capability.

Thanks

[ovrebekk]

Hi Akram

The main drawbacks of using capacitive sense on chip is that accuracy and power consumption might not be as good as a dedicated hardware solution.

You should test it out and make sure that the performance is good enough, compared to using the CAP1203.

Using the csense library in the SDK with the SoftDevice should not be an issue. The connection between the COMP and TIMER modules go through the PPI, which means it can happen in the background even during BLE activity. The processing of the csense events could be delayed, but this shouldn't have a big impact on performance.

We don't have any examples for capacitive sense using the SoftDevice unfortunately, but it should be relatively straight forward to copy the code from the csense example into one of the BLE examples: \nRF5_SDK_14.2.0\examples\peripheral\csense

Best regards
Torbjørn Øvrebekk