I want to know whether accelerometer can measure distance from earth's surface or not. If yes then how to measure it as these accelerometers gives just tilt and g information. also if not then there is any other solution from freescale which I can use for this purpose?
Thanks for using our community. Please notice that accelerometers can only sense acceleration, you could approximate velocity and/or position by integrating the acceleration. I'd recommend you the MMA845x, please click in the following URL for detailed information:
I would rather recommend you another solution like IR or ultrasound. Other way might be to have a "zero point" or a known position, then calculate the steps required to take the arm from the known position to ground (if stepper motors are being used).