Assignment: Servo Motor: Actuation Assignment 2

Collaborators: janani, neha

Description

This time, Janani, Neha, and I made a crawling (walking) Wall-E and a gracefully rotating Eva. Two servo motors are used for Wall-E's legs and one motor is for rotating his head. Under Eva, there is also one motor and this supports her moving as well.

Components

Arduino

4 Servo motors

3 potentiometers

Lego blocks

Eva

Tape

Arduino Code

[Wall-E]

 

/*

* Three servos with two potentiometer controls

* October 21 2009

*

*/

 

int servoPin1 = 7;      // Control pin for servo motor 1

int servoPin2 = 8;      // Control pin for servo motor 2

int servoPin3 = 6;     // Control pin for servo motor 3

int potPin1   = 0;      // select the input pin for the potentiometer 1

int potPin2   = 2;      // select the input pin for the potentiometer 2

 

int pulseWidth1 = 0;    // Amount to pulse the servo 1

int pulseWidth2 = 0;    // Amount to pulse the servo 2

int pulseWidth3 = 0;    // Amount to pulse the servo 3

 

long lastPulse1 = 0;    // the time in millisecs of the last pulse of servo 1

long lastPulse2 = 0;    // the time in millisecs of the last pulse of servo 2

long lastPulse3 = 0;    // the time in millisecs of the last pulse of servo 3

 

int val_1 =0;              // variable used to store data from potentiometer 1

int val_2 =0;              // variable used to store data from potentiometer 2

int val_3 =0; // variable used to store data from potentiometer 3

 

int refreshTime = 20;   // the time in millisecs needed in between pulses

int minPulse = 500;    // minimum pulse width

 

void setup() {

pinMode(servoPin1, OUTPUT);  // Set servo pin 1 as an output pin

pinMode(servoPin2, OUTPUT);  // Set servo pin 2 as an output pin

pinMode(servoPin3, OUTPUT); // Set servo pin 3 as an output pin

 

pulseWidth1 = minPulse;      // Set the motor position to the minimum

pulseWidth2 = minPulse;      // Set the motor position to the minimum

pulseWidth3 = minPulse; // Set the motor position to the minimum

 

Serial.begin(9600);          // connect to the serial port

Serial.println("Three servos with two potentiometers ready");

}

 

void loop() {

val_1 = analogRead(potPin1);    // read the value from the sensor 1, between 0 - 1024

val_2 = analogRead(potPin1);    // read the value from the sensor 2, between 0 - 1024

val_3 = analogRead(potPin2);    // read the value from the sensor 3, between 0 - 1024

Serial.println(potPin1);

Serial.println(potPin2);

 

 

if (val_1 > 0 && val_1 <= 999 ) {

pulseWidth1 = val_1*2 + minPulse;  // convert angle to microseconds

pulseWidth2= val_2*2 + minPulse;

}

updateServo1();   // update servo 1 position

updateServo2();  // update servo 2 position

Serial.println("Servos 1 and 2 updated");

 

if (val_3 > 0 && val_3 <= 999 ) {

pulseWidth3 = val_3*2 + minPulse;  // convert angle to microseconds

}

updateServo3();   // update servo 3 position

Serial.println("Servo 3 updated");

}

 

void updateServo1() {

if (millis() - lastPulse1 >= refreshTime) {

digitalWrite(servoPin1, HIGH);

delayMicroseconds(pulseWidth1);

digitalWrite(servoPin1, LOW);

lastPulse1 = millis();

}

}

 

void updateServo2() {

if (millis() - lastPulse2 >= refreshTime) {

digitalWrite(servoPin2, HIGH);

delayMicroseconds(pulseWidth2);

digitalWrite(servoPin2, LOW);

lastPulse2 = millis();

}

}

 

void updateServo3() {

if (millis() - lastPulse3 >= refreshTime) {

digitalWrite(servoPin3, HIGH);

delayMicroseconds(pulseWidth3);

digitalWrite(servoPin3, LOW);

lastPulse3 = millis();

}

}