refactor: removed tinygo servo driver dependency and added different frequency and angle limits support

Author: ralvarezdev

constants.go

@@ -11,11 +11,13 @@ const (
 
 const (
 	ErrorCodeServoFailedToConfigurePWM tinygoerrors.ErrorCode = tinygoerrors.ErrorCode(iota + ErrorCodeServoStartNumber)
-	ErrorCodeServoFailedToInitializeServo
+	ErrorCodeServoZeroFrequency
 	ErrorCodeServoAngleOutOfRange
-	ErrorCodeServoAngleBelowMinPulseWidth
-	ErrorCodeServoAngleAboveMaxPulseWidth
-	ErrorCodeServoFailedToSetServoAngle
+	ErrorCodeServoInvalidMinPulseWidth
+	ErrorCodeServoInvalidMaxPulseWidth
 	ErrorCodeServoNilHandler
 	ErrorCodeServoUnknownDirection
+	ErrorCodeServoFailedToGetPWMChannel
+	ErrorCodeServoInvalidActuationRange
+	ErrorCodeServoInvalidCenterAngle
 )

errors.go

@@ -5,7 +5,7 @@ go 1.25.0
 require (
 	github.com/ralvarezdev/tinygo-errors v0.0.4
 	github.com/ralvarezdev/tinygo-logger v0.0.9
-	tinygo.org/x/drivers v0.33.0
+	github.com/ralvarezdev/tinygo-pwm v0.1.1
 )
 
 require github.com/ralvarezdev/tinygo-buffers v0.1.3 // indirect

go.mod

@@ -4,5 +4,5 @@ github.com/ralvarezdev/tinygo-errors v0.0.4 h1:nuqApi7tEzPSSf2/3Uqxxizwftvoxczae
 github.com/ralvarezdev/tinygo-errors v0.0.4/go.mod h1:PlkyrG60saZetwFX1mPhve+9l2pneVH7c8q5w4sxe8M=
 github.com/ralvarezdev/tinygo-logger v0.0.9 h1:S19f+yoWqvXJQLas6YJ5dUGRGhR+Qhk64mLGkcfW+dw=
 github.com/ralvarezdev/tinygo-logger v0.0.9/go.mod h1:nkyqp2ph54sYYe6A6XMy9L8aEx7N7jVaVUL9uJCRVFo=
-tinygo.org/x/drivers v0.33.0 h1:5r8Ab0IxjWQi7LzYLNWpya6U4nedo9ZtxeMaAzrJTG8=
-tinygo.org/x/drivers v0.33.0/go.mod h1:ZdErNrApSABdVXjA1RejD67R8SNRI6RKVfYgQDZtKtk=
+github.com/ralvarezdev/tinygo-pwm v0.1.1 h1:bytmDqrnb8M0YFxzMeLlRrhXR8InJSzD+KvqdsPbq/E=
+github.com/ralvarezdev/tinygo-pwm v0.1.1/go.mod h1:7UIppP1HoK+Y89DlhTA3gUE/7ujiVJi+K1c0uO3SGOw=

go.sum

@@ -13,8 +13,6 @@ type (
 		IsAngleCentered() bool
 		SetAngleToCenter() tinygoerrors.ErrorCode
 		SetAngleToRight(angle uint16) tinygoerrors.ErrorCode
-		SafeSetAngleToRight(angle uint16) tinygoerrors.ErrorCode
 		SetAngleToLeft(angle uint16) tinygoerrors.ErrorCode
-		SafeSetAngleToLeft(angle uint16) tinygoerrors.ErrorCode
 	}
 )

interfaces.go

@@ -1,13 +1,11 @@
 package tinygo_servo
 
 import (
-	"time"
-
 	"machine"
 
 	tinygoerrors "github.com/ralvarezdev/tinygo-errors"
 	tinygologger "github.com/ralvarezdev/tinygo-logger"
-	tinygodriversservo "tinygo.org/x/drivers/servo"
+	tinygopwm "github.com/ralvarezdev/tinygo-pwm"
 )
 
 type (
@@ -17,19 +15,24 @@ type (
 		isMovementEnabled   func() bool
 		isDirectionInverted bool
 		frequency           uint16
-		minPulseWidth       uint16
-		halfPulseWidth      uint16
-		maxPulseWidth       uint16
-		rangePulseWidth     uint16
+		minPulseWidth       uint32
+		maxPulseWidth       uint32
 		centerAngle         uint16
-		maxAngle            uint16
-		servo               tinygodriversservo.Servo
+		actuationRange    uint16
+		leftLimitAngle    uint16
+		rightLimitAngle   uint16
 		angle               uint16
 		logger              tinygologger.Logger
+		pwm 			  tinygopwm.PWM
+		channel 		  uint8
+		period 				  uint32
 	}
 )
 
 var (
+	// setPeriodPrefix is the prefix for the log message when setting the PWM period
+	setPeriodPrefix = []byte("Set Servo PWM period to:")
+
 	// setAnglePrefix is the prefix message for new angle setting
 	setAnglePrefix = []byte("Set servo angle degrees to:")
 )
@@ -46,44 +49,95 @@ var (
 // minPulseWidth: The minimum pulse width for the servo motor
 // maxPulseWidth: The maximum pulse width for the servo motor
 // centerAngle: The center angle of the servo motor
-// maxAngle: The maximum angle the servo can move from the center
+// maxLeftAngle: The maximum left angle from the center
+// maxRightAngle: The maximum right angle from the center
 // isDirectionInverted: Whether the direction of the servo motor is inverted
 // logger: The logger instance for logging messages
 //
 // Returns:
 //
 // An instance of DefaultHandler and an error if any occurred during initialization
 func NewDefaultHandler(
-	pwm tinygodriversservo.PWM,
+	pwm tinygopwm.PWM,
 	pin machine.Pin,
 	afterSetAngleFunc func(angle uint16),
 	isMovementEnabled func() bool,
 	frequency uint16,
-	minPulseWidth uint16,
-	maxPulseWidth uint16,
+	minPulseWidth uint32,
+	maxPulseWidth uint32,
+	actuationRange uint16,
 	centerAngle uint16,
-	maxAngle uint16,
+	maxLeftAngle uint16,
+	maxRightAngle uint16,
 	isDirectionInverted bool,
 	logger tinygologger.Logger,
 ) (*DefaultHandler, tinygoerrors.ErrorCode) {
+	// Check if the frequency is zero
+	if frequency == 0 {
+		return nil, ErrorCodeServoZeroFrequency
+	}
+
 	// Configure the PWM
+	period := 1e9 / float64(frequency)
 	if err := pwm.Configure(
 		machine.PWMConfig{
-			Period: uint64(time.Second / time.Duration(frequency)),
+			Period: uint64(period),
 		},
 	); err != nil {
 		return nil, ErrorCodeServoFailedToConfigurePWM
 	}
 
-	// Create a new instance of the servo
-	servo, err := tinygodriversservo.New(pwm, pin)
+	// Log the configured period
+	if logger != nil {
+		logger.AddMessageWithUint32(
+			setPeriodPrefix,
+			uint32(period),
+			true,
+			true,
+			false,
+		)
+		logger.Debug()
+	}
+
+	// Get the channel from the pin
+	channel, err := pwm.Channel(pin)
 	if err != nil {
-		return nil, ErrorCodeServoFailedToInitializeServo
+		return nil, ErrorCodeServoFailedToGetPWMChannel
+	}
+
+	// Check if the min pulse width is valid
+	if minPulseWidth == 0 || minPulseWidth >= uint32(period) {
+		return nil, ErrorCodeServoInvalidMinPulseWidth
+	}
+
+	// Check if the max pulse width is valid
+	if maxPulseWidth == 0 || maxPulseWidth >= uint32(period) {
+		return nil, ErrorCodeServoInvalidMaxPulseWidth
+	}
+
+	// Check if the actuation range is valid
+	if actuationRange == 0 || actuationRange > 360 {
+		return nil, ErrorCodeServoInvalidActuationRange
 	}
 
-	// Calculate the half pulse and range pulse
-	halfPulseWidth := (maxPulseWidth + minPulseWidth) / 2
-	rangePulseWidth := maxPulseWidth - minPulseWidth
+	// Check if the center angle is valid
+	if centerAngle < 0 || centerAngle > actuationRange {
+		return nil, ErrorCodeServoInvalidCenterAngle
+	}
+
+	// Calculate the left and right limit angles
+	leftLimitAngle := centerAngle - maxLeftAngle
+	rightLimitAngle := centerAngle + maxRightAngle
+
+	// Check if the left limit angle is valid
+	if leftLimitAngle < 0 {
+		leftLimitAngle = 0
+	}
+
+	// Check if the right limit angle is valid
+	if rightLimitAngle > actuationRange {
+		rightLimitAngle = actuationRange
+	}
 
 	// Initialize the servo with the provided parameters
 	handler := &DefaultHandler{
@@ -92,14 +146,17 @@ func NewDefaultHandler(
 		isDirectionInverted: isDirectionInverted,
 		frequency:           frequency,
 		minPulseWidth:       minPulseWidth,
-		halfPulseWidth:      halfPulseWidth,
 		maxPulseWidth:       maxPulseWidth,
-		rangePulseWidth:     rangePulseWidth,
-		servo:               servo,
 		angle:               centerAngle,
 		centerAngle:         centerAngle,
+		actuationRange:    actuationRange,
 		logger:              logger,
-		maxAngle:            maxAngle,
+		pwm: 			  pwm,
+		channel: 		  channel,
+		leftLimitAngle:    leftLimitAngle,
+		rightLimitAngle:   rightLimitAngle,
+		period: 				  uint32(period),
+
 	}
 
 	// Center the servo on initialization
@@ -123,10 +180,7 @@ func (h *DefaultHandler) GetAngle() uint16 {
 // angle: The angle to set the servo motor to, must be between 0 and the actuation range
 func (h *DefaultHandler) SetAngle(angle uint16) tinygoerrors.ErrorCode {
 	// Check if the angle is within the valid range
-	if angle < h.centerAngle-h.maxAngle || angle > h.centerAngle+h.maxAngle {
-		return ErrorCodeServoAngleOutOfRange
-	}
-	if angle < LeftLimitAngle || angle > RightLimitAngle {
+	if angle < h.centerAngle-h.leftLimitAngle || angle > h.centerAngle+h.rightLimitAngle {
 		return ErrorCodeServoAngleOutOfRange
 	}
 
@@ -137,21 +191,24 @@ func (h *DefaultHandler) SetAngle(angle uint16) tinygoerrors.ErrorCode {
 
 	// Check if the direction is inverted
 	if h.isDirectionInverted {
-		angle = RightLimitAngle - (angle - LeftLimitAngle)
+		angle = h.rightLimitAngle - (angle - h.leftLimitAngle)
 	}
 
 	// Update the current angle
 	h.angle = angle
 
+	// Calculate the pulse
+	pulse := uint32(h.minPulseWidth) + uint32(float64(h.maxPulseWidth-h.minPulseWidth) * float64(angle) / float64(h.actuationRange))
+
+
 	// Set the servo angle
 	if h.isMovementEnabled == nil || h.isMovementEnabled() {
-		if err := h.servo.SetAngleWithMicroseconds(
-			int(angle),
-			int(h.minPulseWidth),
-			int(h.maxPulseWidth),
-		); err != nil {
-			return ErrorCodeServoFailedToSetServoAngle
-		}
+		tinygopwm.SetDuty(
+			h.pwm,
+			h.channel,
+			pulse,
+			h.period,
+		)
 	}
 
 	// Log the new angle if logger is provided
@@ -200,7 +257,7 @@ func (h *DefaultHandler) SetAngleRelativeToCenter(relativeAngle int16) tinygoerr
 	absoluteAngle := int16(h.centerAngle) + relativeAngle
 
 	// Check if the absolute angle is within the left and right limits
-	if absoluteAngle < int16(LeftLimitAngle) || absoluteAngle > int16(RightLimitAngle) {
+	if absoluteAngle < int16(h.leftLimitAngle) || absoluteAngle > int16(h.rightLimitAngle) {
 		return ErrorCodeServoAngleOutOfRange
 	}
 
@@ -218,23 +275,16 @@ func (h *DefaultHandler) SetAngleRelativeToCenter(relativeAngle int16) tinygoerr
 //
 // An error if the angle is not within the right limit
 func (h *DefaultHandler) SetAngleToRight(angle uint16) tinygoerrors.ErrorCode {
-	return h.SetAngleRelativeToCenter(int16(angle))
-}
+	// Check if the angle is negative
+	if angle < 0 {
+		angle = 0
+	}
 
-// SafeSetAngleToRight sets the servo motor to the right by a specified angle without exceeding limits
-//
-// Parameters:
-//
-// angle: The angle value to move the servo to the right, must be between 0 and the right limit
-//
-// Returns:
-//
-// An error if the angle is not within the right limit
-func (h *DefaultHandler) SafeSetAngleToRight(angle uint16) tinygoerrors.ErrorCode {
-	if angle > h.maxAngle {
-		angle = h.maxAngle
+	// Check if the angle is within the right limit
+	if angle > h.rightLimitAngle-h.centerAngle {
+		angle = h.rightLimitAngle - h.centerAngle
 	}
-	return h.SetAngleToRight(angle)
+	return h.SetAngleRelativeToCenter(int16(angle))
 }
 
 // SetAngleToLeft sets the servo motor to the left by a specified angle
@@ -247,21 +297,14 @@ func (h *DefaultHandler) SafeSetAngleToRight(angle uint16) tinygoerrors.ErrorCod
 //
 // An error if the angle is not within the left limit
 func (h *DefaultHandler) SetAngleToLeft(angle uint16) tinygoerrors.ErrorCode {
-	return h.SetAngleRelativeToCenter(-int16(angle))
-}
+	// Check if the angle is negative
+	if angle < 0 {
+		angle = 0
+	}
 
-// SafeSetAngleToLeft sets the servo motor to the left by a specified angle without exceeding limits
-//
-// Parameters:
-//
-// angle: The angle value to move the servo to the left, must be between 0 and the left limit
-//
-// Returns:
-//
-// An error if the angle is not within the left limit
-func (h *DefaultHandler) SafeSetAngleToLeft(angle uint16) tinygoerrors.ErrorCode {
-	if angle > h.maxAngle {
-		angle = h.maxAngle
+	// Check if the angle is within the left limit
+	if angle > h.centerAngle-h.leftLimitAngle {
+		angle = h.centerAngle - h.leftLimitAngle
 	}
-	return h.SetAngleToLeft(angle)
-}
+	return h.SetAngleRelativeToCenter(-int16(angle))
+}