I have successfully connected the 2-axis IXZ-500 gyroscope to my Jeenode and can read out it's analog values. Does anyone know how you can calculate the tilt angle from the analog input values?
Thanks...
Find the conversion between the analog output of the Jeenode and the angular rate (degrees per second), then integrate over time.
The voltage to angular rate conversion can be found in the datasheet, usually in units of mV/degrees/second. The analog reading can be converted to voltage by m ultiplying the received value by your voltage reference (5.0V for a standard Arduino, I don't know for a Jeenode) and dividing by 1024.
The actual angular rate can be found by subtracting the zero bias (which you need to measure for calibration) from the analog value, then multiplying the remainder by the conversion factor.
Integration over time is simple - use millis() to find the time differential, and keep adding the angular rate * the time differential to a single value - this value will hold the angle. Be aware that gyroscopes DO DRIFT, and are unreliable as singular sources of orientation.