initial support for ttp229 (BSF)

ttp229/ttp229.go

@@ -0,0 +1,109 @@
+// Package ttp229 is for the 16 keys or 8 keys touch pad detector IC
+// Datasheet (BSF version): https://www.sunrom.com/download/SUNROM-TTP229-BSF_V1.1_EN.pdf
+package ttp229 // import "tinygo.org/x/drivers/ttp229"
+
+import (
+	"time"
+
+	"machine"
+)
+
+// Device wraps a connection to a TTP229 device.
+type Device struct {
+	bus      Buser
+	keys     uint16
+	prevKeys uint16
+	inputs   byte
+}
+
+// PinBus holds the structure for GPIO protocol
+type PinBus struct {
+	scl machine.Pin
+	sdo machine.Pin
+}
+
+// Buser interface since there are different versions with different protocols
+type Buser interface {
+	readBits(data byte) uint16
+}
+
+// Configuration
+type Configuration struct {
+	Inputs byte
+}
+
+// NewPin creates a new TTP229 connection through 2 machine.Pin, this is suitable for the BSF variant of the TTP229.
+func NewPin(scl, sdo machine.Pin) Device {
+	scl.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	sdo.Configure(machine.PinConfig{Mode: machine.PinInput})
+	return Device{
+		bus: &PinBus{
+			scl: scl,
+			sdo: sdo,
+		},
+		inputs: 16,
+	}
+}
+
+// Configure sets up the device for communication
+func (d *Device) Configure(cfg Configuration) bool {
+	if cfg.Inputs != 0 {
+		d.inputs = cfg.Inputs
+	}
+	return true
+}
+
+// ReadKeys returns the pressed keys as bits of a uint16
+func (d *Device) ReadKeys() uint16 {
+	d.prevKeys = d.keys
+	d.keys = d.bus.readBits(d.inputs)
+	return d.keys
+}
+
+// bitRead return if the specific bit is on/off of the given uint16
+func (d *Device) bitRead(number uint16, bit byte) bool {
+	return (number & (0x0001 << bit)) != 0
+}
+
+// GetKey returns the current pressed key (only returns one key, even in multitouch mode)
+func (d *Device) GetKey() int8 {
+	for i := byte(0); i < d.inputs; i++ {
+		if !d.bitRead(d.keys, byte(i)) {
+			return int8(i)
+		}
+	}
+	return -1
+}
+
+// IsKeyPressed returns true if the given key is pressed
+func (d *Device) IsKeyPressed(key byte) bool {
+	return !d.bitRead(d.keys, key)
+}
+
+// IsKeyDown returns true if the given key was just pressed (and it wasn't previously)
+func (d *Device) IsKeyDown(key byte) bool {
+	return d.bitRead(d.prevKeys, key) && !d.bitRead(d.keys, key)
+}
+
+// IsKeyUp returns true if the given key was released
+func (d *Device) IsKeyUp(key byte) bool {
+	return !d.bitRead(d.prevKeys, key) && d.bitRead(d.keys, key)
+}
+
+// readBits returns the pressed keys as bits of a uint16
+func (b *PinBus) readBits(inputs byte) uint16 {
+	b.scl.High()
+	time.Sleep(1 * time.Millisecond)
+	var pressed uint16
+	for i := byte(0); i < inputs; i++ {
+		b.scl.Low()
+		time.Sleep(1 * time.Millisecond)
+		if b.sdo.Get() {
+			pressed = pressed | (0x0001 << i)
+		}
+		b.scl.High()
+		time.Sleep(1 * time.Millisecond)
+	}
+	time.Sleep(1 * time.Millisecond)
+	return pressed
+}