How to detect the touch force using CSD sensor

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
SuCh_2227511
Level 3
Level 3
First like received First like given

I am wondering the way to detect the touch force with CSD sensor (full auto mode). My device is CY8C4248LQI-BL583.

My BLE MIDI controller has 16 capsenses and can work simutaneously but It could be better to add velocity data by sensing the touch force when pressed. Please advise. Thanks.

0 Likes
1 Solution
Hari
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi SuCh_2227511​\

CapSense cannot directly detect the force of touch, since the physical capacitance does not change with the force.

One indirect way is to design a large button and measure the raw counts in the application firmware. The idea here is that when there is a force touch, there will be more area of finger in contact with the sensor, and since area is higher, Cf is higher and proportionately, raw counts will be higher.


However, this is not a reliable method and might require precise tuning and setting of threshold values for proper operation.

Regards,

Hari

View solution in original post

0 Likes
1 Reply
Hari
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi SuCh_2227511​\

CapSense cannot directly detect the force of touch, since the physical capacitance does not change with the force.

One indirect way is to design a large button and measure the raw counts in the application firmware. The idea here is that when there is a force touch, there will be more area of finger in contact with the sensor, and since area is higher, Cf is higher and proportionately, raw counts will be higher.


However, this is not a reliable method and might require precise tuning and setting of threshold values for proper operation.

Regards,

Hari

0 Likes