Implement tinygo.Pin wrapper for automatic pin mode handling

Author: ysoldak

examples/dht/main.go

@@ -8,10 +8,11 @@ import (
 	"time"
 
 	"tinygo.org/x/drivers/dht"
+	"tinygo.org/x/drivers/tinygo"
 )
 
 func main() {
-	pin := &machinePin{pin: machine.D6}
+	pin := tinygo.New(machine.D6)
 	dhtSensor := dht.New(pin, dht.DHT11)
 	for {
 		temp, hum, err := dhtSensor.Measurements()
@@ -24,27 +25,3 @@ func main() {
 		time.Sleep(time.Second * 2)
 	}
 }
-
-// machinePin wraps machine.Pin to ensure correct pin mode is set when Get or Set methods are called.
-
-type machinePin struct {
-	pin     machine.Pin
-	mode    machine.PinMode
-	modeSet bool
-}
-
-func (p *machinePin) Get() bool {
-	if !p.modeSet || p.mode != machine.PinInput {
-		p.pin.Configure(machine.PinConfig{Mode: machine.PinInput})
-		p.mode = machine.PinInput
-	}
-	return p.pin.Get()
-}
-
-func (p *machinePin) Set(high bool) {
-	if !p.modeSet || p.mode != machine.PinOutput {
-		p.pin.Configure(machine.PinConfig{Mode: machine.PinOutput})
-		p.mode = machine.PinOutput
-	}
-	p.pin.Set(high)
-}

examples/hcsr04/main.go

@@ -5,10 +5,13 @@ import (
 	"time"
 
 	"tinygo.org/x/drivers/hcsr04"
+	"tinygo.org/x/drivers/tinygo"
 )
 
 func main() {
-	sensor := hcsr04.New(machine.D10, machine.D9)
+	trigger := tinygo.New(machine.D10) // automatically configures pin as output
+	echo := tinygo.New(machine.D9)     // automatically configures pin as input
+	sensor := hcsr04.New(trigger, echo)
 	sensor.Configure()
 
 	println("Ultrasonic starts")

hcsr04/hcsr04.go

@@ -5,20 +5,22 @@
 package hcsr04
 
 import (
-	"machine"
 	"time"
+
+	"tinygo.org/x/drivers"
 )
 
 const TIMEOUT = 23324 // max sensing distance (4m)
 
 // Device holds the pins
 type Device struct {
-	trigger machine.Pin
-	echo    machine.Pin
+	trigger drivers.PinOutput
+	echo    drivers.PinInput
 }
 
-// New returns a new ultrasonic driver given 2 pins
-func New(trigger, echo machine.Pin) Device {
+// New returns a new ultrasonic driver given 2 pins.
+// Pins must be configured as output (trigger) and input (echo).
+func New(trigger drivers.PinOutput, echo drivers.PinInput) Device {
 	return Device{
 		trigger: trigger,
 		echo:    echo,
@@ -27,8 +29,7 @@ func New(trigger, echo machine.Pin) Device {
 
 // Configure configures the pins of the Device
 func (d *Device) Configure() {
-	d.trigger.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.echo.Configure(machine.PinConfig{Mode: machine.PinInput})
+	// no-op, left for API compatibility
 }
 
 // ReadDistance returns the distance of the object in mm
@@ -45,11 +46,11 @@ func (d *Device) ReadDistance() int32 {
 // ReadPulse returns the time of the pulse (roundtrip) in microseconds
 func (d *Device) ReadPulse() int32 {
 	t := time.Now()
-	d.trigger.Low()
+	d.trigger.Set(false)
 	time.Sleep(2 * time.Microsecond)
-	d.trigger.High()
+	d.trigger.Set(true)
 	time.Sleep(10 * time.Microsecond)
-	d.trigger.Low()
+	d.trigger.Set(false)
 	i := uint8(0)
 	for {
 		if d.echo.Get() {

tinygo/pin.go

@@ -0,0 +1,39 @@
+//go:build baremetal && tinygo
+
+package tinygo // import "tinygo.org/x/drivers/tinygo"
+
+import "machine"
+
+// tinygo.Pin wraps machine.Pin to ensure correct pin mode is set when Get or Set methods are called.
+
+type Pin struct {
+	pin  machine.Pin
+	mode machine.PinMode
+
+	modeSet   bool
+	inputMode machine.PinMode
+}
+
+func New(pin machine.Pin) *Pin {
+	return &Pin{pin: pin, inputMode: machine.PinInput}
+}
+
+func NewWithInputMode(pin machine.Pin, inputMode machine.PinMode) *Pin {
+	return &Pin{pin: pin, inputMode: inputMode}
+}
+
+func (p *Pin) Get() bool {
+	if !p.modeSet || p.mode != p.inputMode {
+		p.pin.Configure(machine.PinConfig{Mode: p.inputMode})
+		p.mode = machine.PinInput
+	}
+	return p.pin.Get()
+}
+
+func (p *Pin) Set(high bool) {
+	if !p.modeSet || p.mode != machine.PinOutput {
+		p.pin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+		p.mode = machine.PinOutput
+	}
+	p.pin.Set(high)
+}