https://github.com/todbot/touchytouch

Capacitive sense (capsense) touch Arduino library that mimics how CircuitPython touchio work
https://github.com/todbot/touchytouch

arduino capacitive capsense circuitpython rp2040 sense touch touchio

Last synced: 18 days ago
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Capacitive sense (capsense) touch Arduino library that mimics how CircuitPython touchio work

• Host: GitHub
• URL: https://github.com/todbot/touchytouch
• Owner: todbot
• License: mit
• Created: 2024-02-05T02:18:08.000Z (10 months ago)
• Default Branch: main
• Last Pushed: 2024-02-05T19:47:13.000Z (10 months ago)
• Last Synced: 2024-10-10T22:41:05.576Z (about 1 month ago)
• Topics: arduino, capacitive, capsense, circuitpython, rp2040, sense, touch, touchio
• Language: C++
• Homepage:
• Size: 9.77 KB
• Stars: 3
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# TouchyTouch

Capacitive sense touch Arduino library that mimics how CircuitPython `touchio` works.

This library emulates how the CircuitPython touchio library implements capacitive touch sensing.

It also includes basic button debouncing.

It is based on the CircuitPython "touchio" code at: https://github.com/adafruit/circuitpython/blob/main/shared-module/touchio/TouchIn.c

The `touchio` code is not platform-specific, but does require a 1M pull-down resistor.

Thus the `TouchyTouch` Arduino library is also not platform-specific and also requires a pull-down resistor.

### How it works:

From the `touchio` C code:

```

// This is a capacitive touch sensing routine using a single digital

// pin.  The pin should be connected to the sensing pad, and to ground

// via a 1Mohm or thereabout drain resistor.  When a reading is taken,

// the pin's capacitance is charged by setting it to a digital output

// 'high' for a few microseconds, and then it is changed to a high

// impedance input.  We measure how long it takes to discharge through

// the resistor (around 50us), using a busy-waiting loop, and average

// over N_SAMPLES cycles to reduce the effects of noise.

```