refactoring and cleanup

internal/control_loop/common.go

@@ -1,6 +1,9 @@
 package control_loop
 
+// ControlLoop defines how a FanController approaches the target value of its curve.
 type ControlLoop interface {
- // Loop advances the control loop
- Loop(target float64, measured float64) float64
+ // Cycle advances the control loop to the next step and returns the new pwm value.
+ // Note: multiple calls to Loop may not result in the same output, as
+ // the control loop may take time into account or have other stateful properties.
+ Cycle(target int, lastSetPwm int) int
 }

internal/control_loop/direct.go

@@ -2,6 +2,7 @@ package control_loop
 
 import (
  "github.com/markusressel/fan2go/internal/util"
+ "math"
  "time"
 )
 
@@ -27,7 +28,7 @@ func NewDirectControlLoop(
  }
 }
 
-func (l *DirectControlLoop) Loop(target float64, measured float64) float64 {
+func (l *DirectControlLoop) Cycle(target int, measured int) int {
  loopTime := time.Now()
 
  dt := loopTime.Sub(l.lastTime).Seconds()
@@ -37,15 +38,22 @@ func (l *DirectControlLoop) Loop(target float64, measured float64) float64 {
  // the pwm adjustment depends on the direction and
  // the time-based change speed limit.
  maxPwmChangeThiStep := float64(l.maxPwmChangePerCycle) * dt
- err := target - measured
+ err := float64(target - measured)
  // we can be above or below the target pwm value,
  // so we substract or add at most the max pwm change,
  // capped to having reached the target
+ var stepTarget float64
  if err > 0 {
  // below desired speed, add pwms
- return util.Coerce(maxPwmChangeThiStep, 0, err)
+ stepTarget = util.Coerce(maxPwmChangeThiStep, 0, err)
  } else {
  // above or at desired speed, subtract pwms
- return util.Coerce(-maxPwmChangeThiStep, err, 0)
+ stepTarget = util.Coerce(-maxPwmChangeThiStep, err, 0)
  }
+
+ // ensure we are within sane bounds
+ coerced := util.Coerce(stepTarget, 0, 255)
+ result := int(math.Round(coerced))
+
+ return result
 }

internal/control_loop/pid.go

@@ -30,13 +30,12 @@ func NewPidControlLoop(
  }
 }
 
-func (l *PidControlLoop) Loop(target float64, lastSetPwm float64) float64 {
- result := l.pidLoop.Loop(target, lastSetPwm)
+func (l *PidControlLoop) Cycle(target int, lastSetPwm int) int {
+ result := l.pidLoop.Loop(float64(target), float64(lastSetPwm))
 
- // TODO: verify this
  // ensure we are within sane bounds
- coerced := util.Coerce(lastSetPwm+result, 0, 255)
+ coerced := util.Coerce(float64(lastSetPwm)+result, 0, 255)
  stepTarget := int(math.Round(coerced))
 
- return float64(stepTarget)
+ return stepTarget
 }

internal/controller/controller.go

@@ -248,7 +248,7 @@ func (f *PidFanController) UpdateFanSpeed() error {
  target := f.calculateTargetPwm()
 
  // the target pwm, approaching the actual target smoothly
- stepTarget := int(f.controlLoop.Loop(float64(target), float64(lastSetPwm)))
+ stepTarget := f.controlLoop.Cycle(target, lastSetPwm)
 
  if target >= 0 {
  _ = trySetManualPwm(f.fan)