Basic driver for Waveshare 7.5" e-ink

Author: jmhobbs

epd7in5v2/epd7in5v2.go

@@ -0,0 +1,226 @@
+package epd7in5v2
+
+import (
+	"machine"
+	"time"
+)
+
+// Waveshare 7.5 inch e-ink display v2
+// https://www.waveshare.com/product/displays/e-paper/epaper-1/7.5inch-e-paper-hat.htm
+//
+// Currently only supporting 2 color display, and full display updates.
+//
+// https://files.waveshare.com/upload/6/60/7.5inch_e-Paper_V2_Specification.pdf
+// https://github.com/waveshareteam/e-Paper/tree/4822c075f5df714f88b02e10c336b4eeff7e603e/Arduino/epd7in5_V2
+
+const WIDTH int = 800
+const HEIGHT int = 480
+const BYTE_WIDTH int = WIDTH / 8
+
+type EPD7in5_V2 struct {
+	cs  machine.Pin
+	rst machine.Pin
+	dc  machine.Pin
+	bsy machine.Pin
+	pwr machine.Pin
+	bus machine.SPI
+}
+
+func New(cs, rst, dc, bsy, pwr machine.Pin, bus machine.SPI) *EPD7in5_V2 {
+	return &EPD7in5_V2{
+		cs:  cs,
+		rst: rst,
+		dc:  dc,
+		bsy: bsy,
+		pwr: pwr,
+		bus: bus,
+	}
+}
+
+func (e *EPD7in5_V2) Configure(sck, sdo machine.Pin) error {
+	e.bsy.Configure(machine.PinConfig{Mode: machine.PinInput})
+	e.cs.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	e.rst.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	e.dc.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	e.pwr.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	e.pwr.High()
+
+	return e.bus.Configure(machine.SPIConfig{
+		Frequency: 2_000_000,
+		SCK:       sck,
+		SDO:       sdo,
+		LSBFirst:  false,
+		Mode:      0,
+	})
+}
+
+func (e *EPD7in5_V2) Command(cmd byte, data []byte) error {
+	e.dc.Low()
+	e.cs.Low()
+	_, err := e.bus.Transfer(cmd)
+	e.cs.High()
+
+	if err != nil || data == nil {
+		return err
+	}
+
+	return e.Data(data)
+}
+
+func (e *EPD7in5_V2) Data(data []byte) error {
+	e.dc.High()
+	e.cs.Low()
+	err := e.bus.Tx(data, []byte{})
+	e.cs.High()
+	return err
+}
+
+func (e *EPD7in5_V2) waitUntilIdle() error {
+	var err error
+	for {
+		if err = e.Command(0x71, nil); err != nil {
+			return err
+		}
+		if e.bsy.Get() {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	time.Sleep(20 * time.Millisecond)
+	return nil
+}
+
+func (e *EPD7in5_V2) Reset() {
+	e.rst.High()
+	time.Sleep(20 * time.Millisecond)
+	e.rst.Low()
+	time.Sleep(20 * time.Millisecond)
+	e.rst.High()
+	time.Sleep(20 * time.Millisecond)
+}
+
+func (e *EPD7in5_V2) Init() error {
+	var err error
+
+	// power setting
+	if err = e.Command(0x01, []byte{0x17, 0x17, 0x3F, 0x3F, 0x11}); err != nil {
+		return err
+	}
+
+	// VCOM DC setting
+	if err = e.Command(0x82, []byte{0x24}); err != nil {
+		return err
+	}
+
+	// booster setting
+	if err = e.Command(0x06, []byte{0x27, 0x27, 0x2F, 0x17}); err != nil {
+		return err
+	}
+
+	// OSC setting
+	if err = e.Command(0x30, []byte{0x06}); err != nil {
+		return err
+	}
+
+	// power on
+	if err = e.Command(0x04, nil); err != nil {
+		return err
+	}
+	time.Sleep(100 * time.Millisecond)
+	if err = e.waitUntilIdle(); err != nil {
+		return err
+	}
+
+	// panel setting
+	if err = e.Command(0x00, []byte{0x3F}); err != nil {
+		return err
+	}
+
+	// resolution setting
+	if err = e.Command(0x61, []byte{0x03, 0x20, 0x01, 0xE0}); err != nil {
+		return err
+	}
+
+	// dual SPI mode (off)
+	if err = e.Command(0x15, []byte{0x00}); err != nil {
+		return err
+	}
+
+	// VCOM and data interval
+	if err = e.Command(0x50, []byte{0x10, 0x00}); err != nil {
+		return err
+	}
+
+	// tcon setting
+	if err = e.Command(0x60, []byte{0x22}); err != nil {
+		return err
+	}
+
+	// Gate/Source Start Setting
+	if err = e.Command(0x65, []byte{0x00, 0x00, 0x00, 0x00}); err != nil {
+		return err
+	}
+
+	// Set LUT
+	if err = e.Command(0x20, []byte{
+		0x00, 0x0F, 0x0F, 0x00, 0x00, 0x01, 0x00, 0x0F, 0x01, 0x0F, 0x01, 0x02, 0x00, 0x0F,
+		0x0F, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	}); err != nil {
+		return err
+	}
+
+	if err = e.Command(0x21, []byte{
+		0x10, 0x0F, 0x0F, 0x00, 0x00, 0x01, 0x84, 0x0F, 0x01, 0x0F, 0x01, 0x02, 0x20, 0x0F,
+		0x0F, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	}); err != nil {
+		return err
+	}
+
+	if err = e.Command(0x22, []byte{
+		0x10, 0x0F, 0x0F, 0x00, 0x00, 0x01, 0x84, 0x0F, 0x01, 0x0F, 0x01, 0x02, 0x20, 0x0F,
+		0x0F, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	}); err != nil {
+		return err
+	}
+
+	if err = e.Command(0x23, []byte{
+		0x80, 0x0F, 0x0F, 0x00, 0x00, 0x01, 0x84, 0x0F, 0x01, 0x0F, 0x01, 0x02, 0x40, 0x0F,
+		0x0F, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	}); err != nil {
+		return err
+	}
+
+	return e.Command(0x24, []byte{
+		0x80, 0x0F, 0x0F, 0x00, 0x00, 0x01, 0x84, 0x0F, 0x01, 0x0F, 0x01, 0x02, 0x40, 0x0F,
+		0x0F, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	})
+}
+
+func (e *EPD7in5_V2) Draw(img []byte) error {
+	var err error
+	if err = e.Command(0x13, img); err != nil {
+		return err
+	}
+	if err = e.Command(0x12, nil); err != nil {
+		return err
+	}
+	time.Sleep(100 * time.Millisecond)
+	return e.waitUntilIdle()
+}
+
+func (e *EPD7in5_V2) Clear() error {
+	return e.Draw(make([]byte, BYTE_WIDTH*HEIGHT))
+}
+
+func (e *EPD7in5_V2) DeepSleep() error {
+	return e.Command(0x07, nil)
+}
+
+func NewImageBuffer() []byte {
+	return make([]byte, BYTE_WIDTH*HEIGHT)
+}

examples/epd7in5v2/.tool-versions

@@ -0,0 +1 @@
+golang 1.23.4

examples/epd7in5v2/main.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/epd7in5v2"
+)
+
+// example for writing to a e-ink display
+func main() {
+	// Pins are for an Adafruit Feather nRF52840 Express
+	bus := machine.SPI0
+	cs := machine.D5
+	dc := machine.D6
+	rst := machine.D9
+	busy := machine.D10
+	pwr := machine.D11
+
+	panel := epd7in5v2.New(cs, rst, dc, busy, pwr, bus)
+	err := panel.Configure(machine.SPI0_SCK_PIN, machine.SPI0_SDO_PIN)
+	if err != nil {
+		panic(err)
+	}
+
+	panel.Reset()
+
+	err = panel.Init()
+	if err != nil {
+		panic(err)
+	}
+
+	buf := epd7in5v2.NewImageBuffer()
+
+	// Draw some stripes
+	var color byte
+	for y := 0; y < epd7in5v2.HEIGHT; y++ {
+		if y/60%2 == 0 {
+			color = 0xFF
+		} else {
+			color = 0x00
+		}
+		for x := 0; x < epd7in5v2.BYTE_WIDTH; x++ {
+			buf[y*epd7in5v2.BYTE_WIDTH+x] = color
+		}
+	}
+
+	err = panel.Draw(buf)
+	if err != nil {
+		panic(err)
+	}
+
+	time.Sleep(5 * time.Second)
+
+	err = panel.Clear()
+	if err != nil {
+		panic(err)
+	}
+
+	err = panel.DeepSleep()
+	if err != nil {
+		panic(err)
+	}
+}

smoketest.sh

@@ -140,6 +140,7 @@ tinygo build -size short -o ./build/test.uf2 -target=pico ./examples/tmc2209/mai
 tinygo build -size short -o ./build/test.hex -target=pico ./examples/tmc5160/main.go
 tinygo build -size short -o ./build/test.uf2 -target=nicenano ./examples/sharpmem/main.go
 tinygo build -size short -o ./build/test.hex -target=feather-nrf52840 ./examples/max6675/main.go
+tinygo build -size short -o ./build/test.hex -target=feather-nrf52840 ./examples/epd7in5v2/main.go
 # network examples (espat)
 tinygo build -size short -o ./build/test.hex -target=challenger-rp2040 ./examples/net/ntpclient/
 # network examples (wifinina)