3 Replies Latest reply on Feb 24, 2016 2:03 AM by danny.van.den.bliek

Raw count differs from basline

danny.van.den.bliek Feb 16, 2016 3:30 AM

Hi,

I'm using the CY8C21534 in a capsense project. If I read correct in the documetation, if no finger on the button, raw count value and baseline value should be the same. In my project with 5 buttons, I set the ref value for 2 buttons to value 4 and for the other 3 buttons ref value is 5.

If I monitor raw count and baseline, I see that for the 3 with ref value 5, raw count matches baseline value. But for the 2 buttons with ref value 4, the raw count differs from the baseline value. ( baseline = 10172 while raw count measures 7992 ).

Anyone an idea what is wrong? My project is enclosed.

Thanks.

Danny

Monitor_sensors.zip 605.4 K

1. Re: Raw count differs from basline

sujayy_86 Feb 22, 2016 4:58 AM (in response to danny.van.den.bliek)

Hi Danny,



Could you please add CSD_ScanSensor(bCtr) before CSD_InitializeSensorBaseline(bCtr); to act as a dummy scan? Since Vref setting is changed, CMOD needs settling time.

I will do a test on your project. Also please let me know whether you are testing this on Development kit or your custom board?



Thanks

Sujay
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2. Re: Raw count differs from basline

danny.van.den.bliek Feb 22, 2016 1:15 PM (in response to sujayy_86)

Hi Sujay,

I'm using this project on my custom board. I will test your solution soon and let you if it is solved.



Best regards,

Danny
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3. Re: Raw count differs from basline

danny.van.den.bliek Feb 24, 2016 2:03 AM (in response to danny.van.den.bliek)

Hi Sujay,

I tested your suggestion, but it doesn't solve the problem. The raw count is still about 2200 units lower then the baseline value for buttons 1 and 2.

For the other buttons, the raw count matches the baseline value.

Any other suggestions?



Danny
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