Accelerometer data transmission

[freddyp007]

I am using a three-dimensional accelerometer. I am planning to use x and y axis for my project. I have connected the two axis to the ADC of my atmega32. So, i'll be getting two 8-bit values of ADC. I want to transmit them through zigbee. How will i know which axis has been received at the other end?

 

[BradtheRad]

* Can you transmit both x and y positions, one after the other as a rigid protocol, regardless whether it was x that has changed, or y? This is the simplest way (but it's probably unsatisfactory or you wouldn't be asking the question).

* Or can you transmit an extra byte of information before each datum is sent? Send a value of 1 as an alert that the next datum is for the x position. Send a 2 to alert that it will be for y position. This assumes the receiving end can understand your protocol.

* Can you intercept the ADC output? Also is it sufficient for you to have only 127 values of resolution for each axis? You could convert all x positions to a positive value (between 0 and 127). Convert all y positions to negative (that is, with the leftmost bit set to 1). Test for a 1 in the leftmost bit at the receiving end.

* Or transmit the x position as an odd value only (by setting the rightmost bit to 1), y position as even values only (with the rightmost bit set to 0). Test for even/odd at the receiving end. Then divide by 2. Again this will work only if you are willing to have only 127 values of resolution per axis.