Just like we did in the previous circuit, copy and paste the code into a new Arduino sketch. Then compile and upload it to your metro.
/* ----------------------------------------------------------- * | Arduino Experimentation Kit Example Code | * | CIRC-03 .: Spin Motor Spin :. (Transistor and Motor) | * ----------------------------------------------------------- * * The Arduinos pins are great for driving LEDs however if you hook * up something that requires more power you will quickly break them. * To control bigger items we need the help of a transistor. * Here we will use a transistor to control a small toy motor * * */ int motorPin = 9; // define the pin the motor is connected to // (if you use pin 9,10,11 or 3you can also control speed) /* * setup() - this function runs once when you turn your Arduino on * We set the motors pin to be an output (turning the pin high (+5v) or low (ground) (-)) * rather than an input (checking whether a pin is high or low) */ void setup() { pinMode(motorPin, OUTPUT); } /* * loop() - this function will start after setup finishes and then repeat * we call a function called motorOnThenOff() */ void loop() // run over and over again { motorOnThenOff(); //motorOnThenOffWithSpeed(); //motorAcceleration(); } /* * motorOnThenOff() - turns motor on then off * (notice this code is identical to the code we used for * the blinking LED) */ void motorOnThenOff(){ int onTime = 2500; //the number of milliseconds for the motor to turn on for int offTime = 1000; //the number of milliseconds for the motor to turn off for digitalWrite(motorPin, HIGH); // turns the motor On delay(onTime); // waits for onTime milliseconds digitalWrite(motorPin, LOW); // turns the motor Off delay(offTime); // waits for offTime milliseconds } /* * motorOnThenOffWithSpeed() - turns motor on then off but uses speed values as well * (notice this code is identical to the code we used for * the blinking LED) */ void motorOnThenOffWithSpeed(){ int onSpeed = 200; // a number between 0 (stopped) and 255 (full speed) int onTime = 2500; //the number of milliseconds for the motor to turn on for int offSpeed = 50; // a number between 0 (stopped) and 255 (full speed) int offTime = 1000; //the number of milliseconds for the motor to turn off for analogWrite(motorPin, onSpeed); // turns the motor On delay(onTime); // waits for onTime milliseconds analogWrite(motorPin, offSpeed); // turns the motor Off delay(offTime); // waits for offTime milliseconds } /* * motorAcceleration() - accelerates the motor to full speed then * back down to zero */ void motorAcceleration(){ int delayTime = 50; //milliseconds between each speed step //Accelerates the motor for(int i = 0; i < 256; i++){ //goes through each speed from 0 to 255 analogWrite(motorPin, i); //sets the new speed delay(delayTime); // waits for delayTime milliseconds } //Decelerates the motor for(int i = 255; i >= 0; i--){ //goes through each speed from 255 to 0 analogWrite(motorPin, i); //sets the new speed delay(delayTime); // waits for delayTime milliseconds } }
Motor Not Spinning?
If you sourced your own transistor, double check with the data sheet that the pinout is compatible with a PN2222 (many are reversed).
Check Your Motor
If you sourced your own motor, double check that it will work with 5 volts and that it does not draw too much power.
Still having issues?
Sometimes the Metro board will disconnect from the computer. Try un-plugging and then re-plugging it into your USB port.
Tried the steps above? Still didn't resolve your issue?
Page last edited January 22, 2025
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