01
Introduction
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The touch button is a type of switch based on capacitive sensing, which can be activated by direct contact with the sensor’s metal surface by a human body or metal.
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Principle
The touch sensor module is a capacitive touch switch module based on the touch detection IC (TTP223B). When the module’s metal contact is touched, it is equivalent to pressing a button. We can install the module on non-metal materials such as plastic or glass surfaces, and also cover it with a thin piece of paper (non-metal). As long as the touch position is correct, it can be made into a hidden button located in walls, tabletops, and other places. When our module is touched, the blue light turns on, outputting a high level; otherwise, the blue light turns off, outputting a low level.
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Wiring
The touch button requires three wires:
- G: Power negative, connect to GND
- V: Power positive, connect to 3.3V
- S: Signal line, connect to P0
04
Program
Program Explanation
First, add the extension package: https://github.com/tim2anna/pxt-microblue. When a finger touches the button’s touch area, the letter A is displayed; when the finger leaves the touch area, the screen is cleared.
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Demonstration
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