Crazyflie-Firmware/Stabilizer-(PID-loop).md

+# Setpoint Structure
+
+Setpoint modes:
+- Absolute mode (modeAbs)
+- Velocity mode (modeVelocity)
+- Disabled (modeDisable)
+
+The setpoints have different modes that change how the PID loops interprets the data. 
+
+### Absolute position control
+
+If `setpoint.mode.xyz` is set to `modeAbs` the controller will use values given by `setpoint.position.xyz`.
+
+### Velocity control
+
+If `setpoint.mode.xyz` is set to `modeVelocity` the controller will use values given by `setpoint.velocity.xyz`
+
+In both above cases the `setpoint.mode.` `roll` `pitch` and `yaw` are set to `modeDisable` and attitude is calculated from the position or velocity controller.
+
+### Attitude only control
+
+If however only attitude should be controlled (like when manually flying the Crazyflie through the ground station) **all position modes are set to `modeDisable`**
+
+
 ------
 # References
 - https://www.bitcraze.io/documentation/repository/crazyflie-firmware/master/functional-areas/sensor-to-control/
 - https://www.bitcraze.io/documentation/repository/crazyflie-firmware/2020.06/functional-areas/commanders_setpoints/#setpoint-structure
+- https://git.ece.iastate.edu/danc/MicroCART/-/blob/master/crazyflie_software/crazyflie-firmware-2021.06/src/modules/interface/stabilizer_types.h#L177
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