Bluetooth Controlled Robot

In this blog, I will show you how to build a bluetooth controlled robot with HC-05 bluetooth module and an Arduino microcontroller. You can use any bluetooth mobile app available in playstore to connect you mobile to bluetooth module.

Components required

• Arduino UNO
• HC-05
• Gear Motors
• IC L293D

Arduino UNO

Arduino is an opensource electronics platform based on easy-to-use hardware and software. Arduino boards are able to read inputs - light on a sensor , a finger on a button , or a twitter message - and turn it into an output - activating a motor , turning on a LED , publishing something online. To do so use the Arduino programming language (based on wiring) and the Arduino Software (IDE) based on processing.

HC-05 Bluetooth module

The HC-05 is a popular wireless module that can add two-way (full-duplex) functionality to your projects. You can use this module to communicate between two microcontrollers, such as Arduino, or to communicate with any Bluetooth-enabled device, such as a phone or laptop. Many Android applications are already available, making this process much easier.

Gear Motors

It is a DC motor with a gear box for decreasing the speed and increasing the torque and power . This type of motors is commonly used for robotic applications.

IC L293D

IC L293D is a dual H-bridge motor driver integrated circuit that can drive current of up to 600mA with voltage range of 4.5 to 36 volts.

In that Bluetooth app, tapping 0 turns the motor off, while pressing 1 causes the motor 1 to spin right. Similar to this, when tapping 2 , 3 and 4, the motors 1 turns left , the motor 2 turn right and the motor 2 spins left, respectively.

Code

int motorPin1 = 3; int motorPin2 = 4; int motorPin3 = 5; int motorPin4 = 6; int state; int flag; void setup() { Serial.begin(9600); pinMode(3, OUTPUT); pinMode(4, OUTPUT); pinMode(5, OUTPUT); pinMode(6, OUTPUT); } void loop() { if (Serial.available() > 0) { state = Serial.read(); flag = 0; } if (state == '0') { digitalWrite(3, LOW); digitalWrite(4, LOW); digitalWrite(5, LOW); digitalWrite(6, LOW ); if (flag = 0) { Serial.println("MOTOR:off"); flag = 1; } } else if (state == '1') { digitalWrite(3, LOW); digitalWrite(4, HIGH); if (flag == 0) { Serial.println("MOTOR1:right"); flag = 1; } } else if (state == '2') { digitalWrite(3, HIGH); digitalWrite(4, LOW ); if (flag == 0) { Serial.println("MOTOR1:left"); flag = 1; } } else if (state == '3') { digitalWrite(5, LOW); digitalWrite(6, HIGH); if (flag == 0) { Serial.println("MOTOR2:right"); flag = 1; } } else if (state == '4') { digitalWrite(5, HIGH); digitalWrite(6, LOW ); if (flag == 0) { Serial.println("MOTOR2:LEFT"); flag = 1; } } }