Twig I2C Sensors Do Not Respond


I bought a Twig accelerometer, gyro and compass. None of them seem to respond. I’ve connected them up to Vcc/GND/A4/A5 on my Arduino Diecimila and to the I2C ports on my Seeeduino Mega. I am using the compass reading code provided on the Seeedstudio Wiki. It says this no matter what orientation the sensor is in: “You are heading NorthEast: Angle between X-axis and the South direction 135.0000000000 Deg”.

I also used the following code to scan the I2C bus, and the devices do not show up:

#include "Wire.h"
extern "C" { 
#include "utility/twi.h"  // from Wire library, so we can do bus scanning

// Scan the I2C bus between addresses from_addr and to_addr.
// On each address, call the callback function with the address and result.
// If result==0, address was found, otherwise, address wasn't found
// (can use result to potentially get other status on the I2C bus, see twi.c)
// Assumes Wire.begin() has already been called
void scanI2CBus(byte from_addr, byte to_addr, 
                void(*callback)(byte address, byte result) ) 
  byte rc;
  byte data = 0; // not used, just an address to feed to twi_writeTo()
  for( byte addr = from_addr; addr <= to_addr; addr++ ) {
    rc = twi_writeTo(addr, &data, 0, 1);
    callback( addr, rc );

// Called when address is found in scanI2CBus()
// Feel free to change this as needed
// (like adding I2C comm code to figure out what kind of I2C device is there)
void scanFunc( byte addr, byte result ) {
  Serial.print("addr: ");
  Serial.print( (result==0) ? " found!":"       ");
  Serial.print( (addr%4) ? "\t":"\n");

byte start_address = 1;
byte end_address = 119;

// standard Arduino setup()
void setup()

    Serial.println("\nI2CScanner ready!");

    Serial.print("starting scanning of I2C bus from ");
    Serial.print(" to ");

    // start the scan, will call "scanFunc()" on result from each address
    scanI2CBus( start_address, end_address, scanFunc );


I have tried doing this with and without pull-up resistors. What is going wrong? It seems like the sensors just don’t work.


Are there any support staff around? I’m finding it very difficult to get help with this issue. Might these sensors are defective?