Lab 7: Servo Crawler

Description
For Lab 7, I worked with Stuart Altman to create a servo crawler.  We constructed a body using the box the servo was packaged in.  We used one servo to power a thruster constructed out of an eraser attached to composite board. The other servo was also constructed out of an eraser, and used to prop up the crawler’s body so that the thruster could reset.  We controlled the movement of the servo motors using potentiometers and coordinated both motors (controlled by two different Arduinos) so that the thruster would move the body in a forward direction, the front servo would prop up the body, and subsequently the thruster could be reset. We repeated this series of actions to move the crawler forward.
 
See a video of our crawler here:
http://myhub.pixorial.com/watch/432142fa3b304b9bf5061f21b279acdf
 
Component
2- Arduino Unos
2- Breadboards
2- USB cables
2- Futaba S3003 Servo Motors
2- Potentiometers
1- Futaba S3003 Servo Motor cardboard box
4- Needle point pins
4- Cork pieces
2- Pencil erasers
1- Piece of composite board
+ scotch tape
 
 
Code
(Used to control both servo motors.)
/*
 * Servo with Potentiometer control
 * Theory and Practice of Tangible User Interfaces
 * October 2013
 */
 
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
  }
}