Baby Steps

Description
My servo crawls with the help of a putty foot. The ball of its foot propels it forward when I rapidly rotate the pot by a small angle. The putty holds the “leg” together but also does not constrict the range of motion. It can only be rotated by a small angle only because it won’t otherwise it will go backwards.

Materials
Drill, Putty, Metal Hex, Tape, Toothpick
Clothespin
Servo, Servo Container, Potentiometer
Breadboard, Arduino, Jumper Cables

Code


/*
* Servo with Potentiometer control
* Theory and Practice of Tangible User Interfaces
* October 11 2007
*/

int servoPin = 7; // Control pin for servo motor
int potPin = 0; // select the input pin for the potentiometer

int pulseWidth = 0; // Amount to pulse the servo
long lastPulse = 0; // the time in millisecs of the last pulse
int refreshTime = 20; // the time in millisecs needed in between pulses
int val; // variable used to store data from potentiometer

int minPulse = 500; // minimum pulse width

void setup() {
pinMode(servoPin, OUTPUT); // Set servo pin as an output pin
pulseWidth = minPulse; // Set the motor position to the minimum
Serial.begin(9600); // connect to the serial port
Serial.println("servo_serial_better ready");
}

void loop() {
val = analogRead(potPin); // read the value from the sensor, between 0 - 1024

if (val > 0 && val <= 999 ) { pulseWidth = val*2 + minPulse; // convert angle to microseconds Serial.print("moving servo to "); Serial.println(pulseWidth,DEC); } updateServo(); // update servo position } // called every loop(). void updateServo() { // pulse the servo again if the refresh time (20 ms) has passed: if (millis() - lastPulse >= refreshTime) {
digitalWrite(servoPin, HIGH); // Turn the motor on
delayMicroseconds(pulseWidth); // Length of the pulse sets the motor position
digitalWrite(servoPin, LOW); // Turn the motor off
lastPulse = millis(); // save the time of the last pulse
}
}



Leave a Reply