A motor controller is a device that regulates the speed, torque, and direction of a motor. In this arduino dc motor tutorial, we will discuss how the TIP31C transistor can be used as a motor controller, and how it can be programmed using an Arduino microcontroller.
The TIP31C is a NPN bipolar junction transistor (BJT) that is commonly used for power amplification and switching applications. It is particularly useful as a motor controller due to its high current and power handling capabilities, as well as its fast switching speeds.
The circuit diagram below shows how the TIP31C transistor can be used as a motor controller with an Arduino microcontroller.
The circuit consists of:
- An Arduino microcontroller
- A TIP31C transistor
- A potentiometer
- A DC motor
- Connecting wires and resistors
The potentiometer is connected to analog input pin 0 of the Arduino. The middle pin of the potentiometer is connected to the base of the TIP31C transistor through a resistor. The collector of the TIP31C transistor is connected to the positive terminal of the DC motor, and the emitter is connected to the ground.
The digital output pin 10 of the Arduino is connected to the base of the arduino dc motor transistor TIP31C bipolar junction transistor(BJT) through a 1KOhm resistor. The purpose of the resistor is to limit the current flowing into the base of the transistor, which helps to protect it from damage.
When the program runs on the Arduino, the value of the potentiometer is read, scaled, and written to the digital output pin 10. This changes the voltage at the base of the TIP31C transistor, which in turn controls the current flowing through the collector-emitter circuit, and thus the speed of the DC motor.
The following arduino dc motor code demonstrates how this can be achieved using an Arduino microcontroller.
const int POT = A0;
const int MOT = 10;
void setup () {
Serial.begin(9600);
pinMode(POT, INPUT);
pinMode(MOT, OUTPUT);
}
void loop() {
int p = analogRead(POT);
p = map(p, 0, 1023, 0, 255);
analogWrite(MOT, p);
Serial.println(p);
//delay(100);
}
In the code, const int POT = A0; declares a constant integer "POT" and assigns it the value of analog input pin 0. This pin is connected to a potentiometer, which is used to control the speed of the motor. const int MOT = 10; declares a constant integer "MOT" and assigns it the value of digital output pin 10. This pin is connected to the TIP31C transistor, which is used to control the motor.
In the setup() function, Serial.begin(9600) initializes serial communication with a baud rate of 9600 bits per second, pinMode(POT, INPUT) sets the POT pin as an input, and pinMode(MOT, OUTPUT) sets the MOT pin as an output.
In the loop() function, int p = analogRead(POT) reads the value of the potentiometer on the analog input pin 0 and stores it in a variable p. p = map(p, 0, 1023, 0, 255) scales the value of p from a range of 0 to 1023 to a range of 0 to 255. This is because the analogWrite function can only accept values in the range of 0 to 255.
Finally, analogWrite(MOT, p) writes the scaled value of p to the digital output pin 10 to control the speed of the motor. Serial.println(p) prints the value of p to the serial monitor, which can be used to monitor the speed of the motor.
The following video demonstrates how the DC motor control works with TIP31C bipolar junction transistor and Arduino.
In conclusion, using the TIP31C transistor as a motor controller, in conjunction with an Arduino microcontroller, is an effective and efficient way to control the speed, direction, and torque of a motor. The code provided in this blog post demonstrates how this can be achieved, and serves as a starting point for further exploration and development.
If you are interested in TIP31C transistor and want idea where you can use this transistor see TIP31C Transistor: A Guide for Arduino Projects. Another powerful transistor that is better to use to control motor is to use MOSFET transistor like IRF540N which is illustrated in the tutorial IRF540N: The Ultimate Guide for Arduino Users.
