fix: sero trim works

Author: ielaajezdev

service.yaml

@@ -34,12 +34,12 @@ configuration:
   - name: servo-scaler
     type: number
     tunable: true
-    value: 1
+    value: 0.9
 
   - name: servo-trim
     type: number
     tunable: true
-    value: 0
+    value: 0.0
 
   - name: fan-cap
     type: number

src/drivers/pca9685/init.go

@@ -63,9 +63,9 @@ func NewPCA9685Controller(address uint8, bus uint) (*PCA9685Controller, error) {
 	jumpTable := map[ActuationIndex]channelConfig{
 		ActuationIndex(Steer): {
 			InUse:        true,
-			MinPulseFrac: 225,
-			MaxPulseFrac: 385,
-			Trim:         1,
+			MinPulseFrac: 205, // 1ms up
+			MaxPulseFrac: 410, // 2ms up
+			Trim:         0,
 		},
 		ActuationIndex(LeftThrottle): {
 			InUse:        true,
@@ -148,30 +148,6 @@ func abs(value float64) float64 {
 	return value
 }
 
-// Update the frequency at index @p channel to @p value using the trim value
-func (pc *PCA9685Controller) SetChannelWithTrim(channel ActuationIndex, value float64) error {
-
-	// Calculate duty cycles range
-	trim := pc.jumpTable[channel].Trim
-	maxDuty := pc.jumpTable[channel].MaxPulseFrac
-	minDuty := pc.jumpTable[channel].MinPulseFrac
-
-	// log.Debug().float64("trimBefore", trim).float64("valueBefore", value).Msg("asdf")
-
-	if trim > 0 {
-		maxDuty = maxDuty + (abs(trim) * travelExtender)
-	} else if trim < 0 {
-		minDuty = minDuty - (abs(trim) * travelExtender)
-	}
-
-	dutyRange := maxDuty - minDuty
-	dutyCycle := int(minDuty + (dutyRange * value))
-
-	// log.Debug().float64("trim", trim).float64("value", value).float64("dutyRange", dutyRange).float64("maxDuty", maxDuty).float64("minDuty", minDuty).Msg("SetChannelWithTrim")
-
-	return pc.pca.SetChannel(int(channel), 0, dutyCycle)
-}
-
 // AllOff sets all channels to their midpoints)
 func (pc *PCA9685Controller) AllOff() {
 	log.Info().Msg("Turning off all channels")

src/drivers/pca9685/interface.go

@@ -8,22 +8,29 @@ const servoLimiter = 0.8
 
 // Set the servo duty. In range -1 (left) to 1(right).
 func (pc *PCA9685Controller) SetServo(value float64, servoScaler float64) {
-	value = value * -servoLimiter
+	// value = value * -servoLimiter
 	value = clamp(value)
 
-	trim := pc.jumpTable[Steer].Trim
-	if trim != 0 {
-		value = value * abs(1.0-(trim*0.75)) * servoScaler
-	} else {
-		value = value * servoScaler
-	}
+	// Calculate the duty cycle range
+	maxDuty := pc.jumpTable[Steer].MaxPulseFrac
+	minDuty := pc.jumpTable[Steer].MinPulseFrac
+	dutyRange := maxDuty - minDuty
 
-	value = ((value + 1) / 2)
+	// This gets added or subtracted from the midpoint
+	halfRange := dutyRange / 2.0
 
-	err := pc.SetChannelWithTrim(Steer, value)
-	if err != nil {
-		log.Error().Err(err).Msg("Error setting Steer value")
-	}
+	// We do not want to "oversteer" the servo, which might damage it
+	// so we limit the range
+	halfRange *= servoScaler
+
+	// Find the center of the range
+	center := minDuty + (dutyRange / 2.0)
+	servoTrim := pc.jumpTable[Steer].Trim
+
+	// Calculate the new duty cycle
+	// (due to an annoying convention, we do - right and + left)
+	dutyCycle := int(center - (halfRange * (value - servoTrim)))
+	pc.pca.SetChannel(int(Steer), 0, dutyCycle)
 }
 
 func (pc *PCA9685Controller) SetServoTrim(value float64) {