pwm: update drivers with PWM to use new interface

examples/apa102/itsybitsy-m0/main.go

@@ -15,7 +15,7 @@ import (
 var (
 	apa apa102.Device
 
-	led   = machine.PWM{machine.LED}
+	pwm   = machine.TCC0
 	leds  = make([]color.RGBA, 1)
 	wheel = &Wheel{Brightness: 0x10}
 )
@@ -27,12 +27,19 @@ func init() {
 	apa = apa102.NewSoftwareSPI(machine.PA00, machine.PA01, 1)
 
 	// Configure the regular on-board LED for PWM fading
-	machine.InitPWM()
-	led.Configure()
-
+	err := pwm.Configure(machine.PWMConfig{})
+	if err != nil {
+		println("failed to configure PWM")
+		return
+	}
 }
 
 func main() {
+	channelLED, err := pwm.Channel(machine.LED)
+	if err != nil {
+		println("failed to configure LED PWM channel")
+		return
+	}
 
 	// We'll fade the on-board LED in a goroutine to show/ensure that the APA102
 	// works fine with the scheduler enabled.  Comment this out to test this code
@@ -43,11 +50,11 @@ func main() {
 				brightening = !brightening
 				continue
 			}
-			var brightness uint16 = uint16(i) << 8
+			var brightness uint32 = uint32(i)
 			if !brightening {
-				brightness = 0xFFFF - brightness
+				brightness = 256 - brightness
 			}
-			led.Set(brightness)
+			pwm.Set(channelLED, pwm.Top()*brightness/256)
 			time.Sleep(5 * time.Millisecond)
 		}
 	}()

examples/l293x/speed/main.go

@@ -8,19 +8,31 @@ import (
 )
 
 const (
-	maxSpeed = 30000
+	maxSpeed = 100
 )
 
 func main() {
-	machine.InitPWM()
+	err := machine.TCC0.Configure(machine.PWMConfig{
+		Period: 16384e3, // 16.384ms
+	})
+	if err != nil {
+		println(err.Error())
+		return
+	}
+
+	spc, err := machine.TCC0.Channel(machine.D12)
+	if err != nil {
+		println(err.Error())
+		return
+	}
 
-	wheel := l293x.NewWithSpeed(machine.D10, machine.D11, machine.PWM{machine.D12})
+	wheel := l293x.NewWithSpeed(machine.D10, machine.D11, spc, machine.TCC0)
 	wheel.Configure()
 
 	for i := 0; i <= 10; i++ {
 		println("Forward")
-		var i uint16
-		for i = 0; i < maxSpeed; i += 1000 {
+		var i uint32
+		for i = 0; i < maxSpeed; i += 10 {
 			wheel.Forward(i)
 			time.Sleep(time.Millisecond * 100)
 		}
@@ -30,7 +42,7 @@ func main() {
 		time.Sleep(time.Millisecond * 1000)
 
 		println("Backward")
-		for i = 0; i < maxSpeed; i += 1000 {
+		for i = 0; i < maxSpeed; i += 10 {
 			wheel.Backward(i)
 			time.Sleep(time.Millisecond * 100)
 		}

examples/l9110x/speed/main.go

@@ -8,19 +8,38 @@ import (
 )
 
 const (
-	maxSpeed = 30000
+	maxSpeed = 100
 )
 
 func main() {
-	machine.InitPWM()
+	machine.D11.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	machine.D12.Configure(machine.PinConfig{Mode: machine.PinOutput})
 
-	wheel := l9110x.NewWithSpeed(machine.PWM{machine.D11}, machine.PWM{machine.D12})
+	err := machine.TCC0.Configure(machine.PWMConfig{})
+	if err != nil {
+		println(err.Error())
+		return
+	}
+
+	ca, err := machine.TCC0.Channel(machine.D11)
+	if err != nil {
+		println(err.Error())
+		return
+	}
+
+	cb, err := machine.TCC0.Channel(machine.D12)
+	if err != nil {
+		println(err.Error())
+		return
+	}
+
+	wheel := l9110x.NewWithSpeed(ca, cb, machine.TCC0)
 	wheel.Configure()
 
 	for i := 0; i <= 10; i++ {
 		println("Forward")
-		var i uint16
-		for i = 0; i < maxSpeed; i += 1000 {
+		var i uint32
+		for i = 0; i < maxSpeed; i += 10 {
 			wheel.Forward(i)
 			time.Sleep(time.Millisecond * 100)
 		}
@@ -30,7 +49,7 @@ func main() {
 		time.Sleep(time.Millisecond * 1000)
 
 		println("Backward")
-		for i = 0; i < maxSpeed; i += 1000 {
+		for i = 0; i < maxSpeed; i += 10 {
 			wheel.Backward(i)
 			time.Sleep(time.Millisecond * 100)
 		}

l293x/l293x.go

@@ -56,49 +56,71 @@ func (d *Device) Stop() {
 	d.en.Low()
 }
 
+// PWM is the interface necessary for controlling the motor driver.
+type PWM interface {
+	Configure(config machine.PWMConfig) error
+	Channel(pin machine.Pin) (channel uint8, err error)
+	Top() uint32
+	Set(channel uint8, value uint32)
+	SetPeriod(period uint64) error
+}
+
 // PWMDevice is a motor with speed control.
 // a1 and a2 are the directional GPIO pins.
 // en is the PWM pin that controls the motor speed.
 type PWMDevice struct {
 	a1, a2 machine.Pin
-	en     machine.PWM
+	spc    uint8
+	pwm    PWM
 }
 
-// NewWithSpeed returns a new PWMMotor driver that uses a PWM pin to control speed.
-func NewWithSpeed(direction1, direction2 machine.Pin, speedPin machine.PWM) PWMDevice {
+// NewWithSpeed returns a new PWMMotor driver that uses an already configured PWM channel
+// to control speed.
+func NewWithSpeed(direction1, direction2 machine.Pin, spc uint8, pwm PWM) PWMDevice {
 	return PWMDevice{
-		a1: direction1,
-		a2: direction2,
-		en: speedPin,
+		a1:  direction1,
+		a2:  direction2,
+		spc: spc,
+		pwm: pwm,
 	}
 }
 
-// Configure configures the PWMDevice.
-func (d *PWMDevice) Configure() {
+// Configure configures the PWMDevice. Note that the PWM interface and
+// channel must already be configured, this function will not do it for you.
+func (d *PWMDevice) Configure() error {
 	d.a1.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	d.a2.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.en.Configure()
 
 	d.Stop()
+
+	return nil
 }
 
-// Forward turns motor on in forward direction at specific speed.
-func (d *PWMDevice) Forward(speed uint16) {
+// Forward turns motor on in forward direction at specific speed as a percentage.
+func (d *PWMDevice) Forward(speed uint32) {
+	if speed > 100 {
+		speed = 100
+	}
+
 	d.a1.High()
 	d.a2.Low()
-	d.en.Set(speed)
+	d.pwm.Set(d.spc, d.pwm.Top()*speed/100)
 }
 
-// Backward turns motor on in backward direction at specific speed.
-func (d *PWMDevice) Backward(speed uint16) {
+// Backward turns motor on in backward direction at specific speed as a percentage.
+func (d *PWMDevice) Backward(speed uint32) {
+	if speed > 100 {
+		speed = 100
+	}
+
 	d.a1.Low()
 	d.a2.High()
-	d.en.Set(speed)
+	d.pwm.Set(d.spc, d.pwm.Top()*speed/100)
 }
 
 // Stop turns motor off.
 func (d *PWMDevice) Stop() {
 	d.a1.Low()
 	d.a2.Low()
-	d.en.Set(0)
+	d.pwm.Set(d.spc, 0)
 }

l9110x/l9110x.go

@@ -49,42 +49,52 @@ func (d *Device) Stop() {
 	d.ib.Low()
 }
 
+// PWM is the interface necessary for controlling the motor driver.
+type PWM interface {
+	Configure(config machine.PWMConfig) error
+	Channel(pin machine.Pin) (channel uint8, err error)
+	Top() uint32
+	Set(channel uint8, value uint32)
+	SetPeriod(period uint64) error
+}
+
 // PWMDevice is a motor with speed control.
 // ia and ib are the directional/speed PWM pins.
 type PWMDevice struct {
-	ia, ib machine.PWM
+	pwm    PWM
+	ca, cb uint8
 }
 
 // NewWithSpeed returns a new PWMMotor driver that uses 2 PWM pins to control both direction and speed.
-func NewWithSpeed(direction1, direction2 machine.PWM) PWMDevice {
+func NewWithSpeed(ca, cb uint8, pwm PWM) PWMDevice {
 	return PWMDevice{
-		ia: direction1,
-		ib: direction2,
+		pwm: pwm,
+		ca:  ca,
+		cb:  cb,
 	}
 }
 
-// Configure configures the PWMDevice.
-func (d *PWMDevice) Configure() {
-	d.ia.Configure()
-	d.ib.Configure()
-
+// Configure configures the PWMDevice. Note that the pins, PWM interface,
+// and channels must all already be configured.
+func (d *PWMDevice) Configure() (err error) {
 	d.Stop()
+	return
 }
 
-// Forward turns motor on in forward direction at specific speed.
-func (d *PWMDevice) Forward(speed uint16) {
-	d.ia.Set(speed)
-	d.ib.Set(0)
+// Forward turns motor on in forward direction at specific speed as a percentage.
+func (d *PWMDevice) Forward(speed uint32) {
+	d.pwm.Set(d.ca, d.pwm.Top()*speed/100)
+	d.pwm.Set(d.cb, 0)
 }
 
-// Backward turns motor on in backward direction at specific speed.
-func (d *PWMDevice) Backward(speed uint16) {
-	d.ia.Set(0)
-	d.ib.Set(speed)
+// Backward turns motor on in backward direction at specific speed as a percentage.
+func (d *PWMDevice) Backward(speed uint32) {
+	d.pwm.Set(d.ca, 0)
+	d.pwm.Set(d.cb, d.pwm.Top()*speed/100)
 }
 
 // Stop turns motor off.
 func (d *PWMDevice) Stop() {
-	d.ia.Set(0)
-	d.ib.Set(0)
+	d.pwm.Set(d.ca, 0)
+	d.pwm.Set(d.cb, 0)
 }