Project details

Authors: Soobum Kim and Jack Maseberg

Here is my recent arduino code for our robot.

/* prototype_unified_test

• /

1. include <Wire.h>

char val; // variable to receive data from the serial port int ledpin = 13; // LED connected to pin 13 (on-board LED) int HMC6352SlaveAddress = 0x42; int HMC6352ReadAddress = 0x41; //"A" in hex, A command is: int headingValue; const int LMDir = 12; // Left motor direction const int RMDir = 13; // Right motor direction const int LMSpeed = 9; // PWM for Left motor connected to digital pin 9 const int RMSpeed = 10; // PWM for Right motor connected to digital pin 10

void setup() {

 pinMode(2, OUTPUT);
 pinMode(ledpin = 13, OUTPUT);  // pin 13 (on-board LED) as OUTPUT
   TCCR1B = TCCR1B & 0b11111000 | 0x01; //set PWM freq to 31250 Hz on pins 9 and 10
 pinMode(12, OUTPUT);  // sets the pin as output
 pinMode(13, OUTPUT);  // sets the pin as output
 pinMode(LMSpeed, OUTPUT);  // sets the pin as output
 pinMode(RMSpeed, OUTPUT);  // sets the pin as output
   // "The Wire library uses 7 bit addresses throughout. 
 //If you have a datasheet or sample code that uses 8 bit address, 
 //you'll want to drop the low bit (i.e. shift the value one bit to the right), 
 //yielding an address between 0 and 127."
 HMC6352SlaveAddress = HMC6352SlaveAddress >> 1; // I know 0x42 is less than 127, but this is still required
 Wire.begin();

 Serial.begin(115200);       // start serial communication at 115200bps

}

void loop() {

 digitalWrite(2, LOW);
 if( Serial.available() )       // if data is available to read
 {;}
   val = Serial.read();         // read it and store it in 'val'

 if( val == '0' )               // if '0' was received led 13 is switched off

 {
  digitalWrite(ledpin, LOW);    // turn Off pin 13 off

delay(200); // waits for a second Serial.println("13 off");

 }

if( val == '1' ) // if '1' was received led 13 on

  {
    Serial.println("13 on");
 digitalWrite(13, HIGH);   // set the LED on
 delay(200);              // wait for a second

}

if(val == 'f' )

{

 Serial.println("Motor Forward");
 digitalWrite(LMDir, LOW);  // digital write to set direction (LOW or HIGH)
 digitalWrite(RMDir, LOW);  // digital write to set direction (LOW or HIGH)
 analogWrite(LMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 analogWrite(RMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 delay(10);

}

if(val == 'b' ) {

 Serial.println("Motor Backward");
 digitalWrite(LMDir, HIGH);  // digital write to set direction (LOW or HIGH)
 digitalWrite(RMDir, HIGH);  // digital write to set direction (LOW or HIGH)
 analogWrite(LMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 analogWrite(RMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 delay(10);

}

if(val == 's' ) {

 Serial.println("Motor Stop");
 digitalWrite(LMDir, LOW);  // digital write to set direction (LOW or HIGH)
 digitalWrite(RMDir, LOW);  // digital write to set direction (LOW or HIGH)
 analogWrite(LMSpeed, 0);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 analogWrite(RMSpeed, 0);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 delay(10);

}

if(val == 'r') {

 Serial.println("Motor Rotation Right");
 digitalWrite(LMDir, HIGH);  // digital write to set direction (LOW or HIGH)
 digitalWrite(RMDir, LOW);  // digital write to set direction (LOW or HIGH)
 analogWrite(LMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 analogWrite(RMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 delay(10);

}

if(val == 'l') {

 Serial.println("Motor Rotation Left");
 digitalWrite(LMDir, LOW);  // digital write to set direction (LOW or HIGH)
 digitalWrite(RMDir, HIGH);  // digital write to set direction (LOW or HIGH)
 analogWrite(LMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 analogWrite(RMSpeed, 200);  // analogWrite values from 0 to 255 correspond to 0% and 100% duty cycle
 delay(10);

}

 //"Get Data. Compensate and Calculate New Heading"
 Wire.beginTransmission(HMC6352SlaveAddress);
 Wire.write(HMC6352ReadAddress);              // The "Get Data" command
 Wire.endTransmission();

 //time delays required by HMC6352 upon receipt of the command
 //Get Data. Compensate and Calculate New Heading : 6ms
 delay(6);

 Wire.requestFrom(HMC6352SlaveAddress, 2); //get the two data bytes, MSB and LSB

 //"The heading output data will be the value in tenths of degrees
 //from zero to 3599 and provided in binary format over the two bytes."
 byte MSB = Wire.read();
 byte LSB = Wire.read();

 float headingSum = (MSB << 8) + LSB; //(MSB / LSB sum)
 float headingInt = headingSum / 10; 

 Serial.print(headingInt);
 Serial.println(" degrees");

 delay(100);

}