Example Code for Arduino-IIC Mode Communication

Software Preparation

Arduino IDE; Wire library (included in Arduino IDE by default). Copy the sketch into the arduino IDE, and upload.

Wiring Diagram

Sample Code

    /*************
    This sketch is revised by LEFF in DFRobot, based on the official one with
    LCD05 display @ http://www.robot-electronics.co.uk/files/arduino_cmps10.ino
    *************/

    #include <Wire.h>

    #define ADDRESS 0x60                                          // Defines address of CMPS10

    void setup(){
      Serial.begin(9600);
      Wire.begin();                                               // Conects I2C
    }

    void loop(){
      byte highByte, lowByte, fine;              // highByte and lowByte store high and low bytes of the bearing and fine stores decimal place of bearing
      char pitch, roll;                          // Stores pitch and roll values of CMPS10, chars are used because they support signed value
      int bearing;                               // Stores full bearing

      Wire.beginTransmission(ADDRESS);           //starts communication with CMPS10
      Wire.write(2);                              //Sends the register we wish to start reading from
      Wire.endTransmission();

      Wire.requestFrom(ADDRESS, 4);              // Request 4 bytes from CMPS10
      while(Wire.available() < 4);               // Wait for bytes to become available
      highByte = Wire.read();
      lowByte = Wire.read();
      pitch = Wire.read();
      roll = Wire.read();

      bearing = ((highByte<<8)+lowByte)/10;      // Calculate full bearing
      fine = ((highByte<<8)+lowByte)%10;         // Calculate decimal place of bearing

      display_data(bearing, fine, pitch, roll);  // Display data to the Serial
      delay(500);
    }

    void display_data(int b, int f, int p, int r){    // pitch and roll (p, r) are recieved as ints instead oif bytes so that they will display corectly as signed values.

      Serial.print("CMPS10 Example V:");
      Serial.println(soft_ver());                        // Display software version of the CMPS10

      delay(5);                                       // Delay to allow Serial to proscess data

      Serial.print("Bearing = ");                      // Display the full bearing and fine bearing seperated by a decimal poin on the Serial
      Serial.print(b);
      Serial.print(".");
      Serial.println(f);

      delay(5);

      Serial.print("Pitch = ");
      Serial.println(p);

      delay(5);

      Serial.print("Roll = ");
      Serial.println(r);
    }

    int soft_ver(){
      int data;                                      // Software version of  CMPS10 is read into data and then returned

      Wire.beginTransmission(ADDRESS);
      // Values of 0 being sent with write need to be masked as a byte so they are not misinterpreted as NULL this is a bug in arduino 1.0
      Wire.write((byte)0);                           // Sends the register we wish to start reading from
      Wire.endTransmission();

      Wire.requestFrom(ADDRESS, 1);                  // Request byte from CMPS10
      while(Wire.available() < 1);
      data = Wire.read();

      return(data);
    }

Result

The serial port will output the CMPS10 software version, bearing (with one decimal place), pitch, and roll values. The expected output format is as follows:

CMPS10 Example V: [version]
Bearing = [value].[fine]
Pitch = [value]
Roll = [value]

Additionally, the following image shows the product in use: