User Manual

117
Lesson 24 Touch Switch
Introduction
A touch sensor operate with the conductivity of human body. When you touch the metal on
the base electrode of the transistor, the level of pin SIG will turn over.
Components
- 1 * Raspberry Pi
- 1 * Breadboard
- 4 * Jumper wires (Male to Male, 2 red and 2 black)
- 1 * Network cable (or USB wireless network adapter)
- 1 * Touch sensor module
- 1 * Dual-Color LED module
- 2 * 3-Pin anti-reverse cable
Experimental Principle
In this experiment, touch the base electrode of the transistor by fingers to make it conduct
as human body itself is a kind of conductor and an antenna that can receive
electromagnetic waves in the air. These electromagnetic wave signals collected from the
human body are amplified by the transistor and processed by the comparator on the
module to output steady signals. The schematic diagram: