problem regarding capacitive touch buttons

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Hello..

I am working on a QTouch project having 12 buttons working on mutual capacitance principle.

For this I am using ATSAMD20J18 microcontroller and PTC library. 

I have designed a double sided PCB as required for mutual capacitance application. I have attached the project summary screenshots of QTouch project builder and the PCB designs in this post. Pls have a look.

 

Problem is when I press a button, other buttons get activated simultaneously. I am using 3 mm acrylic sheet as a touch surface.

I have attached additional grounded blank pcb below tracks side after inserting insulation between them for noise suppression. But not getting +ve results.

 

Thanks in advance. 

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Firstly analyse the false touch detection issue is due to over-sensitivity or due to nearby noise sources.

 

Try reducing gain parameter (use GAIN_1) and increase detect threshold of all sensor (such that it is 60 to 70% of touch delta).

This would help if the issue had occurred due to over-sensitivity of sensors.

 

If the false touch issue is due to noise, try the below suggestions:

Try increasing the Filter_level parameter.

Use different set of Hop frequencies, as you use Frequency Mode Hop.

Increase the internal Series Resistor parameter to maximum possible.

Please refer “Section 2.2.5 PTC Tuning” in PTC Robustness Design Guide for more details.

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Hello, 

Are you resolved the problem?

 

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Rathna Dinesh wrote:

Firstly analyse the false touch detection issue is due to over-sensitivity or due to nearby noise sources.

 

Try reducing gain parameter (use GAIN_1) and increase detect threshold of all sensor (such that it is 60 to 70% of touch delta).

This would help if the issue had occurred due to over-sensitivity of sensors.

 

If the false touch issue is due to noise, try the below suggestions:

Try increasing the Filter_level parameter.

Use different set of Hop frequencies, as you use Frequency Mode Hop.

Increase the internal Series Resistor parameter to maximum possible.

Please refer “Section 2.2.5 PTC Tuning” in PTC Robustness Design Guide for more details.