Me Line Follower

Overview

This module has a potentiometer which can be used to adjust the detection range. The level of Mode pin can be controlled to select the operating mode. When it is in high level, the module can be triggered repeatedly for real-time induction. When it is in low level, the module is in non-repeatable trigger mode. If somebody is moving in the induction range, the module is triggered and maintained for a period of time. In this period, the state will not be interfered whether there is somebody moving in the deduction range.

Technical specifications

● Operating voltage: 5V DC
● Detection range: 1~2cm
● Detection angle: within 120°
● Control mode: Double-digital port control
● Module dimension: 51 x 24 x 21mm (L x W x H)

Functional characteristics

● White area of module is the reference area to contact metal beams
● Provide two LED indicators for feedback during line-following
● Anti-reverse protection – connecting the power supply inversely will not damage IC
● Easy to be influenced by natural light, and limited by greatly changed ambient light
● Support mBlock GUI programming, and applicable to users of all ages
● Adopt RJ25 port for easy connection
● Provide pin-type port to support most development boards including Arduino series

Pin definition

The port of Me Line Follower has four pins, and their functions are as follows:

Wiring mode

● Connecting with RJ25
Since the port of Me Line Follower has blue ID, you need to connect the port with blue ID on Makeblock Orion when using RJ25 port. Taking Makeblock Orion
as example, you can connect to ports No. 3, 4, 5, and 6 as follows:

● Connecting with Dupont wire
When the Dupont wire is used to connect the module to the Arduino UNO Baseboard, its S1 and S2 pins should be connected to digital ports as follows:

Guide to programming

● Arduino programming
If you use Arduino to write a program, the library Makeblock-Library-master should be invoked to control the Me Line Follower.

The function of the code segment is: to read the results detected by the sensor of Me Line Follower continuously and output the results to the serial monitor in Arduino IDE every 200 ms. Upload the code segment to Makeblock Orion and click the Arduino serial monitor, and you will see the running results as follows:

● mBlock programming
Me Line Follower supports the mBlock programming environment and its instructions are introduced as follows:

Principle analysis

Me Line Follower is an accessory of robot developed on the principle of reflective photoelectric sensor. The infrared light features different reflection intensity when irradiating on different color of object surface. In the process of running, the cart irradiates infrared light on the floor continuously. When the infrared light reaches white paper floor, diffuse reflection occurs and the reflected light is received by a receiver mounted on the cart. If the infrared light reaches black line, it is absorbed and can not be received by the receiver of cart. By identifying whether the reflected infrared light is received, we can determine the position of black line and the running line of cart. (The output is 0 when irradiating to a black line, and the output is 1 when irradiating to a white line).

Schematic