Controlling the speed of a externally powered DC Motor

Description

The Arduino can only provide 5V. This is far from what this motor needs to achieve its full speed. An external power source is used instead. The voltage provided to the motor can be controlled using the potentiometer.

Parts used

• 12V Battery
• Arduino Leonardo
• DC motor (previously used by a printer)
• TIP 120 transistor
• 10k Ohm Potentiometer
• 1N4001 Diode

Code

 void setup() {
   pinMode(9, OUTPUT);
 }

 void loop() {
   int sensorValue = analogRead(A0);
   int outputValue = map(sensorValue, 0, 1023, 0, 255);
   analogWrite(9, outputValue);
   delay(100);
 }

Notes

• Reading the analog value from the serial monitor causes the Arduino to lock up

Links

https://itp.nyu.edu/physcomp/labs/motors-and-transistors/using-a-transistor-to-control-high-current-loads-with-an-arduino/