IO variables

gyroADC/8192*2000 = deg/s

gyroADC/4 ~ deg/s

rcCommand - <-500 - 500> nominal, but is scaled with rcRate/100, max +-1250

inclination - in 0.1 degree, roll and pitch deviation from horizontal position max_angle_inclination - in 0.1 degree, default 50 degrees (500)

axisPID - output to mixer, will be added to throttle(<1000-2000>), output range is <minthrottle, maxthrottle> (default <1150 - 1850>)

PID controller 0, "MultiWii" (default)

Leveling term

``` error = constrain(2*rcCommand[axis], limit +- max_angle_inclination) - inclination[axis] Pacc = constrain(P8[PIDLEVEL]/100 * error, limit +- 5 * D8[PIDLEVEL]) Iacc = intergrate(error, limit +-10000) * I8[PIDLEVEL] / 4096 ```

Gyro term

``` Pgyro = rcCommand[axis]; error = rcCommand[axis] * 10 * 8 / pidProfile->P8[axis] - gyroADC[axis] / 4; (conversion so that error is in deg/s ?) Igyro = integrate(error, limit +-16000) / 10 / 8 * I8[axis] / 100 (conversion back to mixer units ?) ```

reset I term if

• axis rotation rate > +-64deg/s
• axis is YAW and rcCommand>+-100

Mode dependent mix(yaw is always from gyro)

• HORIZON - proportionally according to max deflection ``` deflection = MAX(ABS(rcCommand[PITCH]), ABS(rcCommand[ROLL])) / 500 ; limit to 0.0 .. 1.0 P = Pacc * (1-deflection) + Pgyro * deflection I = Iacc * (1-deflection) + Igyro * deflection ```
• gyro ``` P = Pgyro I = Igyro ```
• ANGLE ``` P = Pacc I = Iacc ```

  Gyro stabilization

``` P -= gyroADC[axis] / 4 * dynP8 / 10 / 8 D = -mean(diff(gyroADC[axis] / 4), over 3 samples) * 3 * dynD8 / 32 [equivalent to :] D = - (gyroADC[axis]/4 - (<3 loops old>gyroADC[axis]/4)) * dynD8 / 32 ```

This can be seen as sum of

• PI controller (handles rcCommand, HORIZON/ANGLE); Igyro is only output based on gyroADC
• PD controller(parameters dynP8/dynD8) with zero setpoint acting on gyroADC