Collision and Heat Avoidance Robot

My first proper project in Arduino! I made this to learn more about the language and venture deeper into electronics and robotics.

Components Used

I used the following components to make the robot. If you cannot obtain them, use TinkerCAD.
However, I feel learning hands-on is a better approach to learning!
Parts Used:

Arduino UNO.
L298D motor driver shield. (You can use the IC too, but using the shield saves quite a bit of time.)
HC-SR04 - Ultrasonic distance sensor.
KY-013 - Analog temperature sensor Module. (Uses a thermistor calibrated at 10kΩ. Based on the Steinhart–Hart model.)
Jumper cables and a soldering iron kit.
A breadboard and a breadboard power supply to power the motor driver. (Can be substituted with a battery)
A metal frame for the robot and 2 standard rubber wheels.
2 DC motors, with a max rotation speed of 200 rpm.

Libraries Used:

AFMotor.h

Sections of the Code:

The source code for the robot has been broken down into sections, and here I will explain the logic of each portion.

int dist()

This function finds out the distance between the obstacle (if within range of the sensor) at any moment in time. It sends the data as an integer to the main function, loop(). For a detailed explanation on how this works, click here.

double temp()

This function uses the KY-013 Module and gets temperature data from the surroundings. It then returns the value as a floating-point number to loop(). For an in-depth explanation, click here.

void forward()

This function orders the robot to move forward. The code snippet is given below. It uses functions from the AFMotor.h library, so make sure to read the documentation to understand it fully.

   rightm.run(FORWARD);
   leftm.setSpeed(255);
   rightm.setSpeed(253);

Here, leftm denotes the left wheel, and rightm indicates the right wheel.

You must have noticed an interesting thing - Both the motors have a slight offset in their speeds.

Strangely, setting the same speed values for both motors created unequal torques in both of them, causing the robot to move slightly to the left. Hence, I had to use a lower speed for my right motor.
This is however, luck-dependent and you might not need to add this offset.

void left()

This function orders the robot to turn left when an obstacle is detected. It does this by ordering the left wheel to rotate backward and the right wheel to rotate forward, causing the robot to turn left. It uses functions from the AFMotor.h library, so make sure to read the documentation to understand it fully.

void stopmot()

This function stops both the left and right motors, effectively stopping the robot's movement.

void loop()

This is the main function that controls the robot's behavior. It first reads the temperature using the temp() function and checks if it is below a certain threshold value. If it is, the robot moves forward using the forward() function if there are no obstacles in front of it. If an obstacle is detected, it turns left using the left() function until the obstacle is no longer detected. If the temperature is above the threshold value, the robot turns left until the temperature goes back below the threshold value. If the program encounters a "goto f" statement, it jumps back to the label "f:", which is located at the beginning of the "if (temp() <= thresh)" block.

Conclusion

This code is a simple example of how an Arduino board can be used to build a robot with collision and heat avoidance capabilities. By using the HC-SR04 and KY-013 sensors, the robot is able to detect obstacles and temperature changes in its environment and respond accordingly. The code can be further optimized and improved to add more features and functionality to the robot.

Cowwl/My-First-Robot