Hints to troubleshoot I2C device

Using Arduino Networking, Protocols, and Devices
#1

Hello,

I have an IR positioning camera from DFRobot (basically it’s the same camera as in a Wii remote).

I try to run the code provided.

// Wii Remote IR sensor  test sample code  by kako http://www.kako.com
// modified output for Wii-BlobTrack program by RobotFreak http://www.letsmakerobots.com/user/1433
// modified for http://DFRobot.com by Lumi, Jan. 2014
 
#include <Wire.h>
 
int IRsensorAddress = 0xB0;
//int IRsensorAddress = 0x58;
int slaveAddress;
int ledPin = 13;
boolean ledState = false;
byte data_buf[16];
int i;
 
int Ix[4];
int Iy[4];
int s;
 
void setup()
{
    slaveAddress = IRsensorAddress >> 1;   // This results in 0x21 as the address to pass to TWI
    Serial.begin(19200);
    Serial.println("Setup begun.");
    pinMode(ledPin, OUTPUT);      // Set the LED pin as output
    Wire.begin();
    // IR sensor initialize
    Write_2bytes(0x30,0x01); delay(10);
    Write_2bytes(0x30,0x08); delay(10);
    Write_2bytes(0x06,0x90); delay(10);
    Write_2bytes(0x08,0xC0); delay(10);
    Write_2bytes(0x1A,0x40); delay(10);
    Write_2bytes(0x33,0x33); delay(10);
    delay(100);
    Serial.println("Setup done.");
}
void loop()
{
    Serial.println("Loop.");
    ledState = !ledState;
    if (ledState) { digitalWrite(ledPin,HIGH); } else { digitalWrite(ledPin,LOW); }
 
    //IR sensor read
    Wire.beginTransmission(slaveAddress);
    Wire.write(0x36);
    Wire.endTransmission();
 
    Wire.requestFrom(slaveAddress, 16);        // Request the 2 byte heading (MSB comes first)
    for (i=0;i<16;i++) { data_buf[i]=0; }
    i=0;
    while(Wire.available() && i < 16) { 
        data_buf[i] = Wire.read();
        i++;
    }
 
    Ix[0] = data_buf[1];
    Iy[0] = data_buf[2];
    s   = data_buf[3];
    Ix[0] += (s & 0x30) <<4;
    Iy[0] += (s & 0xC0) <<2;
 
    Ix[1] = data_buf[4];
    Iy[1] = data_buf[5];
    s   = data_buf[6];
    Ix[1] += (s & 0x30) <<4;
    Iy[1] += (s & 0xC0) <<2;
 
    Ix[2] = data_buf[7];
    Iy[2] = data_buf[8];
    s   = data_buf[9];
    Ix[2] += (s & 0x30) <<4;
    Iy[2] += (s & 0xC0) <<2;
 
    Ix[3] = data_buf[10];
    Iy[3] = data_buf[11];
    s   = data_buf[12];
    Ix[3] += (s & 0x30) <<4;
    Iy[3] += (s & 0xC0) <<2;
 
    for(i=0; i<4; i++)
    {
      if (Ix[i] < 1000)
        Serial.print("");
      if (Ix[i] < 100)  
        Serial.print("");
      if (Ix[i] < 10)  
        Serial.print("");
      Serial.print( int(Ix[i]) );
      Serial.print(",");
      if (Iy[i] < 1000)
        Serial.print("");
      if (Iy[i] < 100)  
        Serial.print("");
      if (Iy[i] < 10)  
        Serial.print("");
      Serial.print( int(Iy[i]) );
      if (i<3)
        Serial.print(",");
    }
    Serial.println("");
    delay(15);
}

void Write_2bytes(byte d1, byte d2)
{
    Wire.beginTransmission(slaveAddress);
    Wire.write(d1); Wire.write(d2);
    Wire.endTransmission();
}

However I got only zeroes, where I should have values in the range 0-1023 when I move IR LEDs in front of the camera.

Is there any way to know if the I2C device is really sending data to the microcontroller such as the “ping” used for IP devices?

Thank you in advance.

#2

Start by using an I2C scanner to confirm the devices address.

Post link to the device and details of how you have it wired to the Arduino.
Does it have/need external pullup resistors or are they built in.

#3

All right, I have tried the I2C scanner and it has failed so I'm going to investigate this first. Thank you for the tip.

#4