Line Following robot is one of the most popular project for hobbyist nowadays. However, instead of using Arduino, I’m using Raspberry Pi for this project since it is also one of the most highly demanded microcontrollers at this moment.
Step by Step (Hardware)
This tutorial is a continuation from the previous tutorial, Controlling DC Motor using MDDS10.
2. In this tutorial, we will add the LSS05 Auto-Calibrating Line Sensor on the robot. This line sensor is typically used in embedded systems and robots in line following tasks.
3. It consist of 5 IR transmitter and IR receiver pairs. LSS05 can be used for either dark or bright line following. Any color with distinction or brightness difference is suitable for LSS05.
4. LSS05 will come with 2020 PCB Connector. So it will be difficult to connect with Raspberry Pi. To connect LSS05 to GPIO pin on Raspberry, you need to cut the end of connector and replace it with another connector.
6. Place LSS05 on the your robot. Make sure the center sensor is perpendicular to the castor.
7. The connection from LSS05 to Raspberry Pi is like below,
|5V||5V (pin 4)|
|GND||GND (pin 25)|
|O1||GPIO 11 (pin 23)|
|O2||GPIO 9 (pin 21)|
|O3||GPIO 10 (pin 19)|
|O4||GPIO 22 (pin 15)|
|O5||GPIO 27 (pin 13)|
|Cal||GPIO 17 (pin 11)|
Step by Step (Programming)
1. In the calibration process, I’ve set the LSS05 sensor to the Dark Line Following Mode. When the sensor detects a dark surface, the indicator LEDs will light up, and it will output high. When no dark line is detected, the output will be low.
2. Since we use 5 pairs of IR sensors, there will be 32 possible conditions (5 bits of permutations) for the incoming sensors. But in this tutorial, we will only consider the more possible conditions for the sensor.
3. These are the conditions that I used in this tutorial:
|(S1:S2:S3:S4:S5)||Display||Speed M1||Speed M2|
4. Next, let’s proceed to program. You can use either Remote Desktop Connection or PuTTY through SSH Client. You can refer to Remote Desktop Connection‘s tutorial to use it.
5. For this tutorial, I already build the code, and place it in Github. Using Raspberry Pi, you will get my code by following this command.
6. First, install the Git services on your Raspberry Pi. Open LX terminal of your Remote Desktop Connection, type:
sudo apt-get install git
7. Open this sample code. Copy the URL of the link.
8. On LX Terminal, write the URL of the link after this command.
python is case sensitive, so make sure to write exactly from the link.
9. To see the list of item that we already have in our Raspberry Pi, type “ls”
As you can see, we will have Raspberry-Pi-Line Following’s file. To open the file, type:
Same as before, type “ls” to see what we have in file.
10. Now, we already enter the file. To open the code, type:
sudo nano LineFollowRpi.py
11. Now you can edit my code by changing the speed, GPIO’s pin or other necessary change based on your condition of game field.
12. Let’s try it. Place your robot on game field. Type this command on your LX Terminal,
sudo python LineFollowRpi.py
13. To stop the program, press CTRL+C.
14. Finish. Hope you enjoy play with your robot.
Ok, that’s all. If you have any question, feel free to ask in our technical forum as we seldom check the tutorial’s comment section. Thank you.