Merge pull request #135 from caternuson/giga_i2c_patch

Patch for GIGA I2C quirk

Author: ladyada

Adafruit_I2CDevice.cpp

@@ -70,6 +70,9 @@ bool Adafruit_I2CDevice::detected(void) {
 #ifdef DEBUG_SERIAL
   DEBUG_SERIAL.print(F("Address 0x"));
   DEBUG_SERIAL.print(_addr);
+#endif
+#ifdef ARDUINO_ARCH_MBED
+  _wire->write(0); // forces a write request instead of a read
 #endif
   if (_wire->endTransmission() == 0) {
 #ifdef DEBUG_SERIAL