Have you checked the pins you are using? SDA and SCL maddeningly shift around between boards. (Worst is the Leonardo, which uses pins 2,3 - so no hardware interrupts if you use I2C!).
Have you checked the pins you are using? SDA and SCL maddeningly shift around between boards. (Worst is the Leonardo, which uses pins 2,3 - so no hardware interrupts if you use I2C!).