Dog Crawl

Description

Crawling dog using a servo motor attached to a wooden stick to push it along. Hardest part was building something that attached the wood stick to the servo motor because any little tilt in the wooden stick resulted in the dog going around in circles and not in a straight line.

Materials

• Arduino Uno
• Servo Motor
• Wood

Video: http://www.youtube.com/watch?v=MrvD4HbyGdY

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 counter = 0;

int counter2 = 0;

int changeValue = 0;

 

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

  Serial.println(changeValue);

  if (counter % 50 == 0) {

    if (counter2 % 2 == 0) {

      changeValue = 2844;

    }

    else if (counter2 % 2 == 1) {

      changeValue = 1680;

    }

    counter2 += 1;

  }

  if (val > 0 && val <= 999 ) {

    pulseWidth = val*2 + minPulse;  // convert angle to microseconds

    

    Serial.print("moving servo to ");

    Serial.println(pulseWidth,DEC);

  

  }

  if (millis() - lastPulse >= refreshTime) {

    digitalWrite(servoPin, HIGH);

    delayMicroseconds(changeValue);

    digitalWrite(servoPin, LOW);

    lastPulse = millis();

  }

  Serial.println(counter);

  counter += 1;

  //updateServo();   // update servo position

}

 

// called every loop(). 

void updateServo() {

  // pulse the servo again if the refresh time (20 ms) has passed:

  Serial.println(pulseWidth);

  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

  }

}