TSC implementation with STM32WB

[gousebasha shaik]

Hi Sir/Madam,

Here are developing a PCB with touch interface. We found the schematic files in st.com website. In that schematic, touch interface is not implemented. Can you please share the suitable link or any reference files to understand the TSC connections, So that it will be very much helpful to complete my project.

Thank You,

[Remi QUINTIN]

You can get details in AN5225 Getting started with touch sensing control on STM32 microcontrollers

Regarding sensors: See chapter 5.5

Regarding way to connect Sensor/shield and group: See chapter 5.5.4

 

With

CSkey = 47nF

RSkey = 10K

CShield = 100nF

RShield = 1K.

[gousebasha shaik]

Hi Sir,

In the above reply, the document AN5225 is showing the content as USB Type-C™ Power Delivery using STM32xx Series MCUs and STM32xxx Series MPUs. Can you pls check again. 

For developing a key, is there any necessity to enable the Shield group also?

Thank You

[gousebasha shaik]

Hi Sir,

Actually in the AN5105, figure 1, has sensor capacitor Cx is used to place finger, Cx is charged and Humanbody coupling to earth.

In case of the active shield, there is no sensor capacitor(Cx), Can u pls help me and what is the difference in both cases.

Thank you,

[gousebasha shaik]

Hi Sir/Madam,

For developing a key, is there any necessity to enable the Shield group also?

[Remi QUINTIN]

No Shield will decrease the sensitivity.

So the best to do in your case is to reduce the length between the sensor and the MCU: no more than 20mm.

[OlivierR]

Hello, Sorry cut&paste issue, AN is AN5105.

Rgds.