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The traffic light module includes three different colors LED which are red, yellow and green color, like the real-life traffic light. When received different frequency of PWM signal, it will provide different pattern of light.


Working Principle

Most of the traffic light module on market will using the concept of common anode to make it easy to use. However, it required 4 pin on the module(3 signal and 1 ground) and consume 3 control pin from the controller, make it become heavy and hard to use on some tiny device. When using PWM method instead of common anode, it can reduce to 3pins and only consume 1 signal pin form the controller, more suitable for the tiny project. The PWM signal can represent in the average voltage output, or duty cycle % in one complete cycle. This module will control by the duty cycle method. The chip on the traffic light module keep recording the incoming PWM signal and distinguish the “states” of traffic light by the preset duty cycle % level table. Then control the turn on /off states of the three LED lights.

Traffic Light


microbit kit set