Me Line Follower
The line follower module is designed for line following robots. There are two sensors, each with an IR transmitting LED and an IR static induction phototransistor. mBot Ranger can move along a black line on a white background or a white line on a black background. It features fast detection and simple circuits. The blue tag on the interface of this module indicates that it is a dual digital interface and that it should be connected to a port with the blue tag on the main control board.
|1||GND||Connect the ground electrode|
|2||VCC||Connect the power cord|
|3||S1||Output the data of sensor 1|
|4||S2||Output the data of sensor 2|
The tag color on the interface of the line follower sensor is blue. When you use an RJ25 connector, you need to connect it to a port with the blue tag on the main control board. Take Makeblock Orion as an example. You can connect it to port 3, port 4, port 5, or port 6 as shown in the following figure.
|Select a port|
|Select a port|
|MeLineFollower(uint8_t port)||Define the port to be connected|
|uint8_t readSensors()||Read the status values of the sensors|
The line follower module is a robotic part developed according to the principle of reflective photoelectric sensor. Since IR has different reflection strength on objects with different colors, infrared light can be continuously emitted to the floor when mBot Ranger is moving. When infrared light is emitted to a white paper floor, diffuse reflection occurs, and the reflected light is absorbed by the absorption tube installed on mBot Ranger. When infrared light meets a black line, it is absorbed, and no reflected light is absorbed by the absorption tube installed on mBot Ranger. The position of the black line and the moving path of the mBot Ranger are determined by whether there is reflected light absorbed by the absorption tube. The output value of the line follower sensor is 0 when a black line is detected, and the output value is 1 when a white line is detected.
The following figure shows a line follower program on mBlock 5, achieving the line following effect through the detection by the infrared probes. The output value is 0 when the line follower sensor detects a black line, and the output value is 1 when it detects a white line.