I have a question regarding l3gd20h-gyro. The sensor output is in radians per second but what is the measurable range from the sensor. In addition, what is the easiest way to determine the absolute angle of the gyroscope (x, y, z -Axis).
The measurable range depends on the sensitivity and for this chip, as datasheet says, it can be ±245 / 500 / 2000 degrees per second.
The absolute angle is not possible to compute using a gyro only. Gyro gives angular velocity at the moment and the measurements drift slightly with time, so a simple integration would not help either.
You need an IMU for this: a complex of gyro, accelerometer (that gives pitch and roll), and a magnetometer (if you’d like to know the yaw angle). The process of conversion from the raw IMU data to the yaw/pitch/roll Euler enagles is not trivial. Google for Madgwick Filter to get the idea. There’s no such node in XOD stdlib.