Can't get Wire to work Xadow GSM

For some reason i can’t get this example code to work as soon as I switch the codes around on each device it works.

Does anyone know what i’m doing wrong?

Xadow GSM

[code]#include <Wire.h>

void setup() {
Wire.begin(8); // join i2c bus with address #8
Wire.onReceive(receiveEvent); // register event
Serial.begin(9600); // start serial for output

void loop() {

// function that executes whenever data is received from master
// this function is registered as an event, see setup()
void receiveEvent(int howMany) {
while (1 < Wire.available()) { // loop through all but the last
char c =; // receive byte as a character
Serial.print©; // print the character
int x =; // receive byte as an integer
Serial.println(x); // print the integer

Arduino Mini

[code]#include <Wire.h>

void setup() {
Wire.begin(); // join i2c bus (address optional for master)

byte x = 0;

void loop() {
Wire.beginTransmission(8); // transmit to device #8
Wire.write("x is "); // sends five bytes
Wire.write(x); // sends one byte
Wire.endTransmission(); // stop transmitting


It’s easy: the MTK 2502 SoC can run only in I2C master mode - see the processor datasheet for “details” (it only mentions that it offers I2C master) … ae990d83e3

Oh okay that make senses.