Application note

How to increase the number of touchkeys for touch sensing applications on STM32 MCUs

Rev 10 - February 2025

Introduction

The guidelines detailed in this document help designers cope with the limited number of channels. The number of touchkeys can be increased and/or a touchkey matrix can be created, keeping the same targeted device.

The touch sensing libraries allow management of the number of channels, which depends on the targeted devices (refer to the product reference manuals for more details).
Table 1. Applicable products
TypeProduct series
Microcontrollers

STM32F0 series, STM32F3 series, STM32L0 series, STM32L1 series, STM32L4 series, STM32L4+ series, STM32L5 series, STM32U0 series, STM32U3 series, STM32U5 series, STM32WB series, STM32WBA series

General information

This document applies to Arm®-based STM32 microcontrollers.
Note: Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.