invert servo option

pi/roverd/camera_servo.go

@@ -118,6 +118,9 @@ func (s *CameraServo) angleToPulse(angle float64) int {
 	}
 	norm := (angle - s.cfg.MinAngle) / totalRange
 	norm = math.Max(0, math.Min(1, norm))
+	if s.cfg.Invert {
+		norm = 1 - norm
+	}
 	pulseRange := s.cfg.MaxPulseUs - s.cfg.MinPulseUs
 	return s.cfg.MinPulseUs + int(math.Round(norm*float64(pulseRange)))
 }
@@ -129,6 +132,9 @@ func (s *CameraServo) pulseToAngle(pulse int) float64 {
 	}
 	norm := float64(pulse-s.cfg.MinPulseUs) / float64(pulseRange)
 	norm = math.Max(0, math.Min(1, norm))
+	if s.cfg.Invert {
+		norm = 1 - norm
+	}
 	return s.cfg.MinAngle + norm*(s.cfg.MaxAngle-s.cfg.MinAngle)
 }
 

pi/roverd/config.go

@@ -93,6 +93,7 @@ type CameraServoConfig struct {
 	HomeAngle     float64 `yaml:"homeAngle" json:"homeAngle"`
 	NudgeDegrees  float64 `yaml:"nudgeDegrees" json:"nudgeDegrees"`
 	AllowRawPulse bool    `yaml:"allowRawPulse" json:"allowRawPulse"`
+	Invert        bool    `yaml:"invert" json:"invert"`
 }
 
 type NightVisionConfig struct {

pi/roverd/roverd.sample.yaml

@@ -32,6 +32,7 @@ cameraServo:
   cycleLen: 20000
   minPulseUs: 900
   maxPulseUs: 2100
+  invert: false
   minAngle: -15
   maxAngle: 30
   homeAngle: 0