(Reference) Servo Motors

Servo Motors

Wiring Diagram

Wiring Guide

Servo Wire	Photon 2
Power	VUSB
Ground	GND
Signal	Any PWM-capable pin

• Important: Most servos will require 5V not 3.3V so use VUSB
• If you want to use a servo with a LiPo battery, see these instructions

Notes on Servo Wire Colors

• The wiring colors vary with different servos so look carefully at your documentation

Operation

• Servo rotates 180 degrees based on input
• Use Servo class to allow you to send rotation values directly to servo
• It is recommended to rotate from 15 degrees to 165 degrees (instead of 0-180) to protect the servo from damage

Code

const int SERVO_PIN = A2;

Servo servoObj;	// step 1: Create the servo object
void setup(){
    // step 2: attach the servo object to the servo pin 
    servoObj.attach(SERVO_PIN);
}

void loop(){
    // step 3: write PWM values to servo pin
    
    servoObj.write(15); //write the servo to position 15 degrees
    delay(1000); //wait one second
    servoObj.write(90); //write the servo to position 90 degrees
    delay(1000);
    servoObj.write(165); //write servo to position 165 degrees
    delay(1000);
}

Jitting

• In some cases, the servo may start to make noise, stutter, or become hot when not it use
• This can be due to a variety of factors such as unstable current supply or interrupts in the Photon 2 execution
• IF this happens, one simple solution is to attach before using the servo, and then detach after

Code: Fixing Jittering

const int SERVO_PIN = A2;
Servo servoObj;
void setup(){ /*no attach code */ }
}
void loop(){
    servoObj.attach(SERVO_PIN);
    servoObj.write(15); //write the servo to position 15 degrees
    delay(1000); //wait one second
    servoObj.write(90); //write the servo to position 90 degrees
    servoObj.detach();
}

Reminder: Photon 2 PWM Pins

• Only certain pins support PWM
  • D1 (SCL or A4)
  • A2
  • A5
  • MISO (D16)
  • MOSI (D15)

Credits

• Images created with Fritzing
• Sparkfun
• Sparkfun