12.4 Servo Motor
We provide a Micro Servo SG90 in our race car kit, which looks like:
Servo Motor
Servo Example 1 - Knob
The code can be found at Examples_Arduino - geek-workshop - essence - _001_Servo - _001_Servo_Knob.ino.
/*
Controlling a servo position using a potentiometer (variable resistor)
by Michal Rinott <http://people.interaction-ivrea.it/m.rinott>
modified on 8 Nov 2013
by Scott Fitzgerald
http://www.arduino.cc/en/Tutorial/Knob
*/
#include <Servo.h>
Servo myservo; // create servo object to control a servo
int potpin = 0; // analog pin used to connect the potentiometer
int val; // variable to read the value from the analog pin
void setup() {
myservo.attach(9); // attaches the servo on pin 9 to the servo object
}
void loop() {
val = analogRead(potpin); // reads the value of the potentiometer (value between 0 and 1023)
val = map(val, 0, 1023, 0, 180); // scale it to use it with the servo (value between 0 and 180)
myservo.write(val); // sets the servo position according to the scaled value
delay(15); // waits for the servo to get there
}
Servo Example 2 - Sweep
/* Sweep
by BARRAGAN <http://barraganstudio.com>
This example code is in the public domain.
modified 8 Nov 2013
by Scott Fitzgerald
http://www.arduino.cc/en/Tutorial/Sweep
*/
#include <Servo.h>
Servo myservo; // create servo object to control a servo
// twelve servo objects can be created on most boards
int pos = 0; // variable to store the servo position
void setup() {
myservo.attach(9); // attaches the servo on pin 9 to the servo object
}
void loop() {
for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
// in steps of 1 degree
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
}
The hardware wiring is left for students to finish as an in-class assignment. The expected result can be referred to Chapter 15.2 - Pan Tilt Control by 2 Servo Motors.
// http://www.robotoid.com/appnotes/arduino-operating-two-servos.html
#include <Servo.h>
int x = 0;
Servo servoPan; // Define pan servo
Servo servoTilt; // Define tilt servo
void setup() {
servoPan.attach(10); // Set pan servo to digital pin 10
servoTilt.attach(9); // Set tilt servo to digital pin 9
}
void loop() { // Loop through motion tests
forward(); // Example: move forward
delay(2000); // Wait 2000 milliseconds (2 seconds)
reverse();
delay(2000);
turnRight();
delay(2000);
turnLeft();
delay(2000);
stopRobot();
delay(2000);
}
// Motion routines for forward, reverse, turns, and stop
void forward() {
servoPan.write(0);
servoTilt.write(180);
}
void reverse() {
servoPan.write(180);
servoTilt.write(0);
}
void turnRight() {
servoPan.write(180);
servoTilt.write(180);
}
void turnLeft() {
servoPan.write(0);
servoTilt.write(0);
}
void stopRobot() {
servoPan.write(90);
servoTilt.write(90);
}
Last modified 5yr ago