Capsense difference on PSoC4 BLE /PSoC 5

DaZh_1276586 · ‎Jan 06, 2021

Hi.

I noticed with the same clock frequency (24MHz). The sample rate of a generic capsense widget on PSoC4 BLE is about 2x faster than PSoC5. Could you explain the reasons?

Also, if I just use the generic widget/(button) and use the raw sensor data, is the PSoC4 SNR better than PSoC5?

Thanks.

BragadeeshV · ‎Jan 07, 2021

Hi @DaZh_1276586 ,

From your timings for PSoC 5, it looks like you have set the scan speed to Very Fast which divides the input clock by 2, Therefore the modclock (speed at which the counter is counted) is 12 MHz. Therefore, scan time = (2 ^13 - 1)/ 12 = 682 uS + Setup time = ~718uS.

However, if modClk in PSoC 4 is 24 MHz, then the expected scan time is (2^13 - 1)/24 = 341 uS + Setup Time. Can you please let me know how you arrived at 171us?

Regards,
Bragadeesh

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Capsense difference on PSoC4 BLE /PSoC 5

Capsense difference on PSoC4 BLE /PSoC 5

Re: Capsense difference on PSoC4 BLE /PSoC 5