> For the complete documentation index, see [llms.txt](https://wiki.purduesigbots.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.purduesigbots.com/vex-electronics/vex-sensors/smart-port-sensors/rotation-sensor.md).
# Rotation Sensor
### Functionality
The 
**V5 Rotation Sensor** is an smart sensor to determine the angle bound by \[0,36000) and the position in centidegrees, as well as the angular velocity in centidegrees / second. The sensor connects to the [V5 Brain](/vex-electronics/vex-electronics/vex-v5-brain.md) through a smart port, and functions similarly to a[ encoder](/vex-electronics/vex-sensors/3-pin-adi-sensors/encoder.md) or [potentiometer](/vex-electronics/vex-sensors/3-pin-adi-sensors/potentiometer.md).
### How it Works
The measurement component of the sensor is comprised of a Hall Effect sensor that measures the magnetic field of 2 magnets to track the absolute angle (\[0,36000)) of the rotation sensor. The angle resets every full rotation of the rotation sensor. A chip inside the rotation sensor (a Cortex M0+) then keeps track of the total rotations which acts as the relative position measurement, which does not reset every rotation.
Since the rotation sensor angle ([get\_angle](https://pros.cs.purdue.edu/v5/pros-4/group__cpp-rotation.html#gac675e49bc52b4b25ce2351742b69b6cb)) is absolute, as it's based on the magnetic field generated, the angular position of the shaft will not reset when it loses power. However, since the chip loses power the position ([get\_position](https://pros.cs.purdue.edu/v5/pros-4/group__cpp-rotation.html#ga28a657dab4a1609b0bddc8ba0c345b57)), which is relative, of the rotation sensor is not tracked and it resets to zero every time the sensor is turned on.
#### Teams/Individuals Contributed to this Article:
* Alyssa Agarie (Former VEX Competitor)
* [BLRS](https://purduesigbots.com/) (Purdue SIGBots)
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