I am using the Grove microphone and the Grove analog-to-digital converter to sample sound. The Grove platform documentation provides the following example C code to read data from the ADC that I am trying to port to Mathematica:

#include <Wire.h>

#define ADDR_ADC121             0x55

#define V_REF 3.00

#define REG_ADDR_RESULT         0x00
#define REG_ADDR_ALERT          0x01
#define REG_ADDR_CONFIG         0x02
#define REG_ADDR_LIMITL         0x03
#define REG_ADDR_LIMITH         0x04
#define REG_ADDR_HYST           0x05
#define REG_ADDR_CONVL          0x06
#define REG_ADDR_CONVH          0x07

unsigned int getData;
float analogVal=0;         // convert
void init_adc()
{
  Wire.beginTransmission(ADDR_ADC121);        // transmit to device
  Wire.write(REG_ADDR_CONFIG);                // Configuration Register
  Wire.write(0x20);
  Wire.endTransmission();  
}

void read_adc()     //unsigned int *data
{


    Wire.beginTransmission(ADDR_ADC121);        // transmit to device
    Wire.write(REG_ADDR_RESULT);                // get result
    Wire.endTransmission();

    Wire.requestFrom(ADDR_ADC121, 2);           // request 2byte from device
    delay(1);
    if(Wire.available()<=2)
    {
      getData = (Wire.read()&0x0f)<<8;
      getData |= Wire.read();
    }
    Serial.print("getData:");
    Serial.println(getData);
    delay(5);
    Serial.print("The analog value is:");
    Serial.print(getData*V_REF*2/4096); 
    Serial.println("V");
}

The code writes 0x20 to 'register 2'. After some trial and error I found out that the Mathematica equivalent seems to be:

DeviceWrite[i2c, {0,0,32}]

because after that I can read data continuously using:

d = DeviceRead[i2c, 2]; n = d[[1]] * 256 + d[[2]]

Is this the way to set 'registers' on an ADC? Also, what does setting it achieve? The Grove documentation is rather vague on this point.

Thanks, Gijsbert