Maximising CapSense poll rate

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willrow
Level 1
Level 1
First question asked Welcome!

Hello,

Recently I have been playing with the CapSense block in PSoC 4.3 with the specific aim of trying to maximise the rate at which I can poll the electrodes for raw data.

PSoC gives a calculated value of scan time for your particular setup of electrodes when you double click the capsense block. I have found this time to be VERY different to timing the difference between CapSense_ScanAllWidgets() and the time at which the block becomes "not busy". I have managed to decrease this time though several methods but I am still not close to the scan time given by PSoC.

My methods for reducing the time so far have been to attach all electrodes to one widget and preload this widget using CapSense_SetupWidget(), prior to scanning with a call to CapSense_CSDScan().

I have also found a variable named CapSense_CSD_ANALOG_STARTUP_DELAY_US, that is set to 10 by default. I have reduced this to 1 to get the 9 us speed increase with apparently little change to signal performance.

Does anyone have any hints as to other methods for increasing the speed of the CapSense block?

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1 Solution
ncbs
Moderator
Moderator
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500 replies posted 50 likes received 250 sign-ins

Hi @willrow,

Which CapSense component are you using? It is recommended to use CapSense v7.0.

How are you measuring the time difference between the instance when CapSense_ScanAllWidgets() is called and the instance when the CapSense block is not busy?

You may refer to the following thread on ways to speed up CapSense widget to have a faster button response : https://community.infineon.com/t5/PSoC-6/How-do-I-speed-up-CapSense-widget-to-have-a-faster-button/m...

 

Regards,
Nikhil

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ncbs
Moderator
Moderator
Moderator
500 replies posted 50 likes received 250 sign-ins

Hi @willrow,

Which CapSense component are you using? It is recommended to use CapSense v7.0.

How are you measuring the time difference between the instance when CapSense_ScanAllWidgets() is called and the instance when the CapSense block is not busy?

You may refer to the following thread on ways to speed up CapSense widget to have a faster button response : https://community.infineon.com/t5/PSoC-6/How-do-I-speed-up-CapSense-widget-to-have-a-faster-button/m...

 

Regards,
Nikhil

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