Add buzzer gpio driver

platforms/gpio/buzzer_driver.go

@@ -0,0 +1,221 @@
+package gpio
+
+import (
+	"time"
+
+	"github.com/hybridgroup/gobot"
+)
+
+const (
+	Whole   = 4
+	Half    = 2
+	Quarter = 1
+	Eighth  = 0.500
+)
+
+const (
+	Rest = 0
+	C0   = 16.35
+	Db0  = 17.32
+	D0   = 18.35
+	Eb0  = 19.45
+	E0   = 20.60
+	F0   = 21.83
+	Gb0  = 23.12
+	G0   = 24.50
+	Ab0  = 25.96
+	A0   = 27.50
+	Bb0  = 29.14
+	B0   = 30.87
+	C1   = 32.70
+	Db1  = 34.65
+	D1   = 36.71
+	Eb1  = 38.89
+	E1   = 41.20
+	F1   = 43.65
+	Gb1  = 46.25
+	G1   = 49.00
+	Ab1  = 51.91
+	A1   = 55.00
+	Bb1  = 58.27
+	B1   = 61.74
+	C2   = 65.41
+	Db2  = 69.30
+	D2   = 73.42
+	Eb2  = 77.78
+	E2   = 82.41
+	F2   = 87.31
+	Gb2  = 92.50
+	G2   = 98.00
+	Ab2  = 103.83
+	A2   = 110.00
+	Bb2  = 116.54
+	B2   = 123.47
+	C3   = 130.81
+	Db3  = 138.59
+	D3   = 146.83
+	Eb3  = 155.56
+	E3   = 164.81
+	F3   = 174.61
+	Gb3  = 185.00
+	G3   = 196.00
+	Ab3  = 207.65
+	A3   = 220.00
+	Bb3  = 233.08
+	B3   = 246.94
+	C4   = 261.63
+	Db4  = 277.18
+	D4   = 293.66
+	Eb4  = 311.13
+	E4   = 329.63
+	F4   = 349.23
+	Gb4  = 369.99
+	G4   = 392.00
+	Ab4  = 415.30
+	A4   = 440.00
+	Bb4  = 466.16
+	B4   = 493.88
+	C5   = 523.25
+	Db5  = 554.37
+	D5   = 587.33
+	Eb5  = 622.25
+	E5   = 659.25
+	F5   = 698.46
+	Gb5  = 739.99
+	G5   = 783.99
+	Ab5  = 830.61
+	A5   = 880.00
+	Bb5  = 932.33
+	B5   = 987.77
+	C6   = 1046.50
+	Db6  = 1108.73
+	D6   = 1174.66
+	Eb6  = 1244.51
+	E6   = 1318.51
+	F6   = 1396.91
+	Gb6  = 1479.98
+	G6   = 1567.98
+	Ab6  = 1661.22
+	A6   = 1760.00
+	Bb6  = 1864.66
+	B6   = 1975.53
+	C7   = 2093.00
+	Db7  = 2217.46
+	D7   = 2349.32
+	Eb7  = 2489.02
+	E7   = 2637.02
+	F7   = 2793.83
+	Gb7  = 2959.96
+	G7   = 3135.96
+	Ab7  = 3322.44
+	A7   = 3520.00
+	Bb7  = 3729.31
+	B7   = 3951.07
+	C8   = 4186.01
+	Db8  = 4434.92
+	D8   = 4698.63
+	Eb8  = 4978.03
+	E8   = 5274.04
+	F8   = 5587.65
+	Gb8  = 5919.91
+	G8   = 6271.93
+	Ab8  = 6644.88
+	A8   = 7040.00
+	Bb8  = 7458.62
+	B8   = 7902.13
+)
+
+var _ gobot.Driver = (*BuzzerDriver)(nil)
+
+// BuzzerDriver represents a digital buzzer
+type BuzzerDriver struct {
+	pin        string
+	name       string
+	connection DigitalWriter
+	high       bool
+	BPM        float64
+}
+
+// NewBuzzerDriver return a new BuzzerDriver given a DigitalWriter, name and pin.
+func NewBuzzerDriver(a DigitalWriter, name string, pin string) *BuzzerDriver {
+	l := &BuzzerDriver{
+		name:       name,
+		pin:        pin,
+		connection: a,
+		high:       false,
+		BPM:        96.0,
+	}
+
+	return l
+}
+
+// Start implements the Driver interface
+func (l *BuzzerDriver) Start() (errs []error) { return }
+
+// Halt implements the Driver interface
+func (l *BuzzerDriver) Halt() (errs []error) { return }
+
+// Name returns the BuzzerDrivers name
+func (l *BuzzerDriver) Name() string { return l.name }
+
+// Pin returns the BuzzerDrivers name
+func (l *BuzzerDriver) Pin() string { return l.pin }
+
+// Connection returns the BuzzerDrivers Connection
+func (l *BuzzerDriver) Connection() gobot.Connection {
+	return l.connection.(gobot.Connection)
+}
+
+// State return true if the buzzer is On and false if the led is Off
+func (l *BuzzerDriver) State() bool {
+	return l.high
+}
+
+// On sets the buzzer to a high state.
+func (l *BuzzerDriver) On() (err error) {
+	if err = l.connection.DigitalWrite(l.Pin(), 1); err != nil {
+		return
+	}
+	l.high = true
+	return
+}
+
+// Off sets the buzzer to a low state.
+func (l *BuzzerDriver) Off() (err error) {
+	if err = l.connection.DigitalWrite(l.Pin(), 0); err != nil {
+		return
+	}
+	l.high = false
+	return
+}
+
+// Toggle sets the buzzer to the opposite of it's current state
+func (l *BuzzerDriver) Toggle() (err error) {
+	if l.State() {
+		err = l.Off()
+	} else {
+		err = l.On()
+	}
+	return
+}
+
+func (l *BuzzerDriver) Tone(hz, duration float64) (err error) {
+	// calculation based off https://www.arduino.cc/en/Tutorial/Melody
+	tone := (1.0 / (2.0 * hz)) * 1000000.0
+
+	tempo := ((60 / l.BPM) * (duration * 1000))
+
+	for i := 0.0; i < tempo*1000; i += tone * 2.0 {
+		if err = l.On(); err != nil {
+			return
+		}
+		<-time.After(time.Duration(tone) * time.Microsecond)
+
+		if err = l.Off(); err != nil {
+			return
+		}
+		<-time.After(time.Duration(tone) * time.Microsecond)
+	}
+
+	return
+}