cancel
Showing results for 
Search instead for 
Did you mean: 

PSoC 4 MCU

New Contributor II

Hi,

I am using CY8CKIT-042 PSoC® 4 Pioneer Kit. I am using it for the CapSense design with 10 buttons and 2 sliders.

I can see that, this kit has an in-built CapSense slider with 5 sensors.

pastedImage_0.png

Due to shortage of pins which are required for my project, I tried using the above in-built capsense pins I,e P1_1, P1_2, P1_3, P1_4 and P1_5 for my external custom CapSense.

But I couldn't get the capsense input sensed through these pins from external capsense.

Please suggest if there is any workaround.

0 Likes
Reply
1 Solution
Moderator
Moderator

Hello TaH_4345166

The reason for CapSense input not being detected from these pins could be due to increased parasitic capacitance (Cp). If you are using smartsense for tuning, then the maximum allowable Cp value is only 45pF. If the parasitic capacitance increases beyond, the sensors will not work. You can try using manual mode for tuning.

You can also use the BIST (Built in self test) library to check the parasitic capacitance of the sensor. For this, you need to change the tuning to manual mode and enable the self test library.

pastedImage_0.png

You can then use the CapSense_GetSensorCapacitance API to check what the Cp of the sensor is.

Another reason could be improper sensor design. Please share the layout files of the sensors that are used so that we can verify the sensor design.

You can enable tuner and see if the sensors are active graphically. Tuner will show the raw counts vs time graph and this can be used to check the increase in raw count (the difference counts) when the sensor is touched to check if sensors are active.

Thanks and regards

Harigovind

View solution in original post

0 Likes
Reply
1 Reply
Moderator
Moderator

Hello TaH_4345166

The reason for CapSense input not being detected from these pins could be due to increased parasitic capacitance (Cp). If you are using smartsense for tuning, then the maximum allowable Cp value is only 45pF. If the parasitic capacitance increases beyond, the sensors will not work. You can try using manual mode for tuning.

You can also use the BIST (Built in self test) library to check the parasitic capacitance of the sensor. For this, you need to change the tuning to manual mode and enable the self test library.

pastedImage_0.png

You can then use the CapSense_GetSensorCapacitance API to check what the Cp of the sensor is.

Another reason could be improper sensor design. Please share the layout files of the sensors that are used so that we can verify the sensor design.

You can enable tuner and see if the sensors are active graphically. Tuner will show the raw counts vs time graph and this can be used to check the increase in raw count (the difference counts) when the sensor is touched to check if sensors are active.

Thanks and regards

Harigovind

View solution in original post

0 Likes
Reply