AN3236 Datasheet, PDF (1/15 Pages) STMicroelectronics – Guidelines to increase the number of touch sensing touchkeys

AN3236
Application note
Guidelines to increase the number of touch sensing touchkeys
Introduction
The touch sensing libraries allow management of the following number of channels
depending on the targeted device series :
• up to 24 channels when using devices from the STM32F0, STM32F3 and STM32L0
series.
• up to 34 channels when using devices from the STM32L1 series.
• up to 6 channels when using devices from the STM8L101 lines.
• up to 20 channels when using devices from the STM8L151/152 and the STM8L162
lines.
• up to 24 channels when using devices from the STM8S and STM8AF series.
The guidelines detailed into this document aim to help designers to overcome channel
number limitation. They describe tips and tricks to increase the number of touchkeys and/or
to create a touchkey matrix by keeping the same targetted device.
Type
Microcontrollers
Table 1. Applicable products
Applicable products
STM32F0 series, STM32F3 series, STM32L0 series, STM32L1 series,
STM8L series, STM8S series, STM8AF series.
May 2014
DocID17613 Rev 3
1/15
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