tm1637: add support for tm1637 7-segment LED

Makefile

@@ -119,6 +119,8 @@ smoke-test:
 	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=circuitplay-bluefruit ./examples/tone
 	@md5sum ./build/test.hex
+	tinygo build -size short -o ./build/test.hex -target=arduino-nano33 ./examples/tm1637/main.go
+	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=pyportal ./examples/touch/resistive/fourwire/main.go
 	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=pyportal ./examples/touch/resistive/pyportal_touchpaint/main.go
@@ -179,7 +181,7 @@ endif
 DRIVERS = $(wildcard */)
 NOTESTS = build examples flash semihosting pcd8544 shiftregister st7789 microphone mcp3008 gps microbitmatrix \
 		hcsr04 ssd1331 ws2812 thermistor apa102 easystepper ssd1351 ili9341 wifinina shifter hub75 \
-		hd44780 buzzer ssd1306 espat l9110x st7735 bmi160 l293x dht keypad4x4 max72xx p1am tone
+		hd44780 buzzer ssd1306 espat l9110x st7735 bmi160 l293x dht keypad4x4 max72xx p1am tone tm1637
 TESTS = $(filter-out $(addsuffix /%,$(NOTESTS)),$(DRIVERS))
 
 unit-test:

examples/tm1637/main.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/tm1637"
+)
+
+func main() {
+
+	tm := tm1637.New(machine.D2, machine.D3, 7) // clk, dio, brightness
+	tm.Configure()
+
+	tm.ClearDisplay()
+
+	tm.DisplayText([]byte("Tiny"))
+	time.Sleep(time.Millisecond * 1000)
+
+	tm.ClearDisplay()
+
+	tm.DisplayChr(byte('G'), 1)
+	tm.DisplayDigit(0, 2) // looks like O
+	time.Sleep(time.Millisecond * 1000)
+
+	tm.DisplayClock(12, 59, true)
+
+	for i := uint8(0); i < 8; i++ {
+		tm.Brightness(i)
+		time.Sleep(time.Millisecond * 200)
+	}
+
+	i := int16(0)
+	for {
+		tm.DisplayNumber(i)
+		i++
+		time.Sleep(time.Millisecond * 50)
+	}
+
+}

tm1637/registers.go

@@ -0,0 +1,16 @@
+package tm1637
+
+const (
+	TM1637_CMD1   = 0x40
+	TM1637_CMD2   = 0xC0
+	TM1637_CMD3   = 0x80
+	TM1637_DSP_ON = 0x08
+	TM1637_DELAY  = uint8(10)
+)
+
+// 7-segment characters encoding for 0-9, A-Z, a-z, blank, dash, star
+var segments []byte = []byte{
+	0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F,
+	0x77, 0x7C, 0x39, 0x5E, 0x79, 0x71, 0x3D, 0x76, 0x06, 0x1E,
+	0x76, 0x38, 0x55, 0x54, 0x3F, 0x73, 0x67, 0x50, 0x6D, 0x78,
+	0x3E, 0x1C, 0x2A, 0x76, 0x6E, 0x5B, 0x00, 0x40, 0x63}

tm1637/tm1637.go

@@ -0,0 +1,215 @@
+// Package tm1637 provides a driver for the TM1637 4-digit 7-segment LED display.
+//
+// Datasheet: https://www.mcielectronics.cl/website_MCI/static/documents/Datasheet_TM1637.pdf
+//
+package tm1637
+
+import (
+	"machine"
+	"time"
+)
+
+// Device wraps the pins of the TM1637.
+type Device struct {
+	clk        machine.Pin
+	dio        machine.Pin
+	brightness uint8
+}
+
+// New creates a new TM1637 device.
+func New(clk machine.Pin, dio machine.Pin, brightness uint8) Device {
+	return Device{clk: clk, dio: dio, brightness: brightness}
+}
+
+// Configure sets up the pins.
+func (d *Device) Configure() {
+	pinMode(d.clk, false)
+	pinMode(d.dio, false)
+	d.clk.Low() // required for future pull-down
+	d.dio.Low() // required for future pull-down
+}
+
+// Brightness sets the brightness of the display (0-7).
+func (d *Device) Brightness(brightness uint8) {
+	if brightness > 7 {
+		brightness = 7
+	}
+	d.brightness = brightness
+	d.writeCmd()
+	d.writeDsp()
+}
+
+// ClearDisplay clears the display.
+func (d *Device) ClearDisplay() {
+	d.writeData([]byte{0, 0, 0, 0}, 0)
+}
+
+// DisplayText shows a text on the display.
+//
+// Only the first 4 letters in the array text would be shown.
+func (d *Device) DisplayText(text []byte) {
+	var sequences []byte
+	for i, t := range text {
+		if i > 3 {
+			break
+		}
+		sequences = append(sequences, encodeChr(t))
+	}
+	d.writeData(sequences, 0)
+}
+
+// DisplayChr shows a single character (A-Z, a-z)
+// on the display at position 0-3.
+func (d *Device) DisplayChr(chr byte, pos uint8) {
+	if pos > 3 {
+		pos = 3
+	}
+	d.writeData([]byte{encodeChr(chr)}, pos)
+}
+
+// DisplayNumber shows a number on the display.
+//
+// Only 4 rightmost digits of the number would be shown.
+//
+// For negative numbers, only -999 to -1 would be
+// shown with a negaive sign.
+func (d *Device) DisplayNumber(num int16) {
+	var sequences []byte
+	var start int16
+	if num < 0 {
+		sequences = append(sequences, segments[37])
+		num *= -1
+		start = 100
+		num %= 1000
+	} else {
+		start = 1000
+		num %= 10000
+	}
+	for i := start; i >= 1; i /= 10 {
+		if num >= i {
+			n := (num / int16(i)) % 10
+			sequences = append(sequences, segments[n])
+		} else {
+			if i == 1 && num == 0 {
+				sequences = append(sequences, segments[0])
+			} else {
+				sequences = append(sequences, 0)
+			}
+		}
+	}
+	d.writeData(sequences, 0)
+}
+
+// DisplayDigit shows a single-digit number (0-9)
+// at position 0-3.
+func (d *Device) DisplayDigit(digit uint8, pos uint8) {
+	digit %= 10
+	d.writeData([]byte{segments[digit]}, pos)
+}
+
+// DisplayClock allows you to display hour and minute numbers
+// together with the colon on/off.
+func (d *Device) DisplayClock(num1 uint8, num2 uint8, colon bool) {
+	var sequences []byte
+	num := []uint8{num1 % 100, num2 % 100}
+	for k := 0; k < 2; k++ {
+		for i := 10; i >= 1; i /= 10 {
+			n := (num[k] / uint8(i)) % 10
+			sequences = append(sequences, segments[n])
+		}
+	}
+	if colon {
+		sequences[1] |= 1 << 7
+	}
+	d.writeData(sequences, 0)
+}
+
+func encodeChr(c byte) byte {
+	r := rune(c)
+	switch {
+	case r == 32:
+		return segments[36] // space
+	case r == 42:
+		return segments[38] // star/degrees
+	case r == 45:
+		return segments[37] // dash
+	case r >= 65 && r <= 90:
+		return segments[r-55] // uppercase A-Z
+	case r >= 97 && r <= 122:
+		return segments[r-87] // lowercase a-z
+	case r >= 48 && r <= 57:
+		return segments[r-48] // 0-9
+	default:
+		return byte(0)
+	}
+}
+
+func delaytm() {
+	time.Sleep(time.Microsecond * time.Duration(TM1637_DELAY))
+}
+
+func pinMode(pin machine.Pin, mode bool) {
+	// TM1637 has internal pull-up resistors for both CLK and DIO pins.
+	// Set them to input mode will pull them high,
+	// and set them to output mode will pull them down
+	// (since we did so in the beginning.)
+	// The High()/Low() method don't work on some boards.
+	if mode {
+		pin.Configure(machine.PinConfig{Mode: machine.PinInput})
+	} else {
+		pin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	}
+}
+
+func (d *Device) start() {
+	pinMode(d.dio, false)
+	delaytm()
+	pinMode(d.clk, false)
+}
+
+func (d *Device) stop() {
+	pinMode(d.dio, false)
+	delaytm()
+	pinMode(d.clk, true)
+	delaytm()
+	pinMode(d.dio, true)
+}
+
+func (d *Device) writeByte(data uint8) {
+	for i := 0; i < 8; i++ {
+		pinMode(d.dio, data&(1<<i) > 0) // send bits from LSB to MSB
+		delaytm()
+		pinMode(d.clk, true)
+		delaytm()
+		pinMode(d.clk, false)
+		delaytm()
+	}
+	pinMode(d.clk, false)
+	delaytm()
+	pinMode(d.clk, true)
+	delaytm()
+	pinMode(d.clk, false)
+}
+
+func (d *Device) writeCmd() {
+	d.start()
+	d.writeByte(TM1637_CMD1)
+	d.stop()
+}
+
+func (d *Device) writeDsp() {
+	d.start()
+	d.writeByte(TM1637_CMD3 | TM1637_DSP_ON | d.brightness)
+	d.stop()
+}
+
+func (d *Device) writeData(segments []byte, position uint8) {
+	d.writeCmd()
+	d.start()
+	d.writeByte(TM1637_CMD2 | position)
+	for _, seg := range segments {
+		d.writeByte(seg)
+	}
+	d.stop()
+	d.writeDsp()
+}