Arduino | Maze Solving Robot (MicroMouse) \ Wall Following Robot




I do stuff sometimes.

Welcome I'm Isaac and this is my first robot "Striker v1.0".
This Robot was designed to solve a simple Maze.
In the competition we had two mazes and the robot was able to identify them.
Any other changes in the maze may require a change in the code and the design but it's all easy to do.

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Step 1: Parts

First Of all You need to know what are you dealing with.

Robots = Electricity + Hardware + Software

1- Electricity: batteries have many specs you should only know how much Current and Voltage you need.

2- Hardware: " Body, Motor, Motor Driver, Sensors, Wires and The Controller " you should only get the important parts that do the task, no need to get a fancy expensive Controller for a simple task.

3- Software: The code is all about logic. Once you understand how the controller works it will become easy for you to choose the functions and to make the code more simple. The code language is determined by the controller type.

Part List:

  1. Arduino UNO
  2. 12v DC motors (x2)
  3. Wheels (x2)
  4. Motor Driver (L298N)
  5. Distance Sensor (Ultra Sonic)
  6. Wires
  7. 12v Battery (1000 mAh)

Tools List:

  1. Battery Charger
  2. Acrylic sheet
  3. Soldering Iron
  4. Wire cutter
  5. Nylon Zip Wrap

For Extra fun you can use LEDs to light it up but it's not very important.

Step 2: Body Design

The main Idea was to stack the parts above the body and use the Nylon Zip Wrap stabilize the Arduino and Wires will stabilize the rest thanks to their lightweight.

I used CorelDRAW To design the body And I made extra holes in case of any future changes.

I went to a local workshop to use the laser cutter then I started to build it all together.
Later On, I made some changes cuz the Motors were longer than I expected.

I want to say that your robot does not have to be built in the same manner as mine.

PDF file and The CorelDRAW File are attached.

If you are not able to laser cut the design, do not worry. As long as you have an Arduino, the same sensors, and motors then you should be able to get my code to work on your robot with minor changes.

Step 3: Implementation (building)

The design made it easy to fix sensors on the body.

Step 4: Wiring

Here is a schematic diagram of the robot. these connections are related to the code.
You can change the connections but make sure to change the code with it.

The parts.


I would like to explain "The Ultrasonic sensor"

An Ultrasonic sensor is a device that can measure the distance to an object by using sound waves. It measures distance by sending out a sound wave at a specific frequency and listening for that sound wave to bounce back. By recording the elapsed time between the sound wave being generated and the sound wave bouncing back.This seems similar to the working of Sonar and Radar.

The connection of the Ultrasonic Sensor to the Arduino:

  1. GND pin is connected to the Ground.
  2. VCC pin is connected to the Positive (5v).
  3. Echo pin is connected to the Arduino. (choose any pin and match it to the code)
  4. TRIG pin is connected to the Arduino. (choose any pin and match it to the code)

You will make a common Ground and connect all GNDs to it ( sensors, Arduino, Driver ) all grounds should be connected.

For Vcc Pins also connect the 3 Sensors to a 5v Pin

( you can connect them to the Arduino Or the Driver I recommend the Driver)

Note: Don't connect the Sensors to a voltage higher than 5v or it will be damaged.


Motor Driver

The L298N H-bridge: it's an IC that can allows you to control the speed and direction of two DC motors, or control one bipolar stepper motor with ease.
The L298N H-bridge driver can be used with motors that have a voltage of between 5 and 35V DC.

There is also an on-board 5v regulator, so if your supply voltage is up to 12v you can also source 5v from the board.

Consider the image – match the numbers against the list below the image:

  1. DC motor 1 “+”
  2. DC motor 1 “-”
  3. 12v jumper – remove this if using a supply voltage greater than 12v DC. This enables the on-board 5v regulator
  4. Connect your motor supply voltage here, maximum of 35v DC.
  5. GND
  6. 5v output if 12v jumper in place
  7. DC motor 1 enable jumper.Remove the jumper and Connect to PWM output for DC motor speed control.
  8. IN1 Direction Control
  9. IN2 Direction Control
  10. IN3 Direction Control
  11. IN4 Direction Control
  12. DC motor 2 enable jumper. Remove the jumper and Connect to PWM output for DC motor speed control
  13. DC motor 2 “+”
  14. DC motor 2 “-”

Note: This Driver allows 1A per channel, draining more current will damage the IC.



I used 12v Battery with 1000 mAh.

The table Above shows how the voltage drops when the battery discharge.
you should keep it in mind and you have to recharge the battery constantly.

Discharge time is basically the Ah or mAh rating divided by the current.

So for a 1000mAh battery with a load that draws 300mA you have:

1000/300 = 3.3 hours

If you drain more current the time will decrease and so on.

Note: Make sure that you don't exceed the Battery Discharge Current or it will be damaged.

Also again make a common Ground and connect all GNDs to it ( sensors, Arduino, Driver ) all grounds should be connected.

Step 5: Coding

I made these into functions and I had fun coding this robot.

The main idea is to avoid hitting walls and to get out of the maze.
we had 2 simple mazes and I had to keep that in mind cuz they were different.

The blue maze uses right wall following algorithm.

The red maze uses left wall following algorithm.

The photo above shows the way out in both mazes.

Code flow:

  1. defining the pins
  2. defining output and input pins
  3. check sensors' readings
  4. use sensors' reading to define walls
  5. check first route (if it was left then follow the left wall, if it's right follow the right wall)
  6. Use PID to avoid hitting the walls and to control motors' speed

You can use this code but change the pins and the constant numbers to get the best results.

Follow This Link for the code.

Follow This Link for the library and the Arduino Code File.

Step 6: Have Fun

Make sure to have fun :D

This is all for fun don't panic if it's not working or if there is any thing wrong. track the error and don't give up.

Thanks for reading and I hope it helped.



Arduino Contest 2017

Participated in the
Arduino Contest 2017

1 Person Made This Project!


  • Made with Math Contest

    Made with Math Contest
  • Multi-Discipline Contest

    Multi-Discipline Contest
  • Robotics Contest

    Robotics Contest

66 Discussions


4 weeks ago

I'm making a robot with a labyrinth measuring 120 cm x 210 cm
Wall covering is 20 cm high, the width of each wall is 30 cm, the vehicle size is 18 x 18 cm
I have seen how to connect hardware but I don't use leds, can you show me and fix the code for me?

2 replies

Simply don't connect any leds, the code will work normally without them .. however, the wall following algorithm isn't designed for the maze you shared in the picture .. it will take longer paths and may not work perfectly for your case (check the maze I shared) and I didn't develop a code that works with the maze you shared .. you may need to check A* algorithm or other memory dependent algorithms ..

Can you help me write a code for this yard, my wall is 30cm wide 18cm wide, 210cm long 120cm wide. Can you please test the code for me? bro


6 weeks ago on Step 5

Hello sir can you please make me a diagram how to connect the motor driver to the arduino coz please
This is for my project

2 replies

Please check Step 4, it's all about wiring .. however, I'm using L298N Motor Driver so if you're using a different driver please check it's data sheet before connecting it .. as some require different codes ..


7 weeks ago

How to fix the diagnostic error it says

Used of undeclared identifier

4 replies

sir its kinda complicated to me sir can you me a diagram for step number 4 please its for my school project


6 months ago

I have an major problem.
I want to do this bot as a obstracle avoiding robot without any maze. For open ground
So what changes I should do in code.

1 reply
Isaac Hossam El-DinShetty12365

Reply 3 months ago

Hi, Great job ..

you can use the same code some changes to force the robot to follow only one wall which will allow you activate obstacle avoiding algorithm ..

for left wall following:

first_turn = true ;
rightWallFollow = false ;
leftWallFollow = true ;

for right wall following:

first_turn = false ;
rightWallFollow = true ;
leftWallFollow = false ;

these modifications will allow you to only follow one wall and avoid obstacles ..
but keep in mind that if the robot doesn't read any wall it will stop .. so make sure it reads at least one wall to keep moving ..

Hope this helped ..


6 months ago

In your cod, I can't understand the enA, enB, RMS, LMS.
What do they work in this car?

1 reply
Isaac Hossam El-Dinmazellanko

Reply 3 months ago


enA >> right motor PWM pin
enB >> left motor PWM pin

RMS >> Right Motor Speed
LMS >> Left Motor Speed

We use enA, enB to direct the controller to the output pins to the motors which the output wave will be written .. we can see that in the beginning of the code we defined them as 10, 11 .. those are the pins which we connected the PWM pins from the driver to ..

We use RMS, LMS to save each motor Speed so we can write them later using the analogWrite command .. and it takes values from 0 to 255 so the PWM generator can write it to the PWM pins ..

Hope this helped ..


7 months ago

It's find the shortest or not?