Gentlemen - My project is a wheel-hub mounted odometer using MEMs devices. It must be ultra low power in standby mode because it has to run a long time from batteries. It needs to detect rotation of the wheel but not shocks, bumps and vibration. I have heard of using accelerometers to do this, but I wonder if a gyro would be better. The wake-up on motion features look very promising. I would love to hear your thoughts about the unique problems that such an application brings with it. This has been done before with accelerometers, but would a gyro be better perhaps? I would appreciate anyone's input and ideas!