support for Waveshare EPD 2.13" display (black&white only) (#61)

* support for Waveshare EPD 2.13" display (black&white only)
2026-08-16 04:43:25 +00:00 · 2019-05-24 12:37:02 +02:00
parent 9127719933
commit 30b118cf63
5 changed files with 386 additions and 0 deletions
@@ -0,0 +1,281 @@
+// Package epd2in13 implements a driver for Waveshare 2.13in black and white e-paper device.
+//
+// Datasheet: https://www.waveshare.com/w/upload/e/e6/2.13inch_e-Paper_Datasheet.pdf
+package epd2in13
+
+import (
+	"errors"
+	"image/color"
+	"machine"
+	"time"
+)
+
+type Config struct {
+	Width  int16
+	Height int16
+}
+
+type Device struct {
+	bus          machine.SPI
+	cs           machine.GPIO
+	dc           machine.GPIO
+	rst          machine.GPIO
+	busy         machine.GPIO
+	width        int16
+	height       int16
+	buffer       []uint8
+	bufferLength uint32
+}
+
+// Look up table for full updates
+var lutFullUpdate = [30]uint8{
+	0x22, 0x55, 0xAA, 0x55, 0xAA, 0x55, 0xAA, 0x11,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x1E, 0x1E, 0x1E, 0x1E, 0x1E, 0x1E, 0x1E, 0x1E,
+	0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
+}
+
+// Look up table for partial updates, faster but there will be some ghosting
+var lutPartialUpdate = [30]uint8{
+	0x18, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x0F, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+}
+
+// New returns a new epd2in13x driver. Pass in a fully configured SPI bus.
+func New(bus machine.SPI, csPin uint8, dcPin uint8, rstPin uint8, busyPin uint8) Device {
+	pinCs := machine.GPIO{csPin}
+	pinCs.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	pinDc := machine.GPIO{dcPin}
+	pinDc.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	pinRst := machine.GPIO{rstPin}
+	pinRst.Configure(machine.GPIOConfig{Mode: machine.GPIO_OUTPUT})
+	pinBusy := machine.GPIO{busyPin}
+	pinBusy.Configure(machine.GPIOConfig{Mode: machine.GPIO_INPUT})
+	return Device{
+		bus:  bus,
+		cs:   pinCs,
+		dc:   pinDc,
+		rst:  pinRst,
+		busy: pinBusy,
+	}
+}
+
+// Configure sets up the device.
+func (d *Device) Configure(cfg Config) {
+	if cfg.Width != 0 {
+		d.width = cfg.Width
+	} else {
+		d.width = 128
+	}
+	if cfg.Height != 0 {
+		d.height = cfg.Height
+	} else {
+		d.height = 250
+	}
+	d.bufferLength = (uint32(d.width) * uint32(d.height)) / 8
+	d.buffer = make([]uint8, d.bufferLength)
+	for i := uint32(0); i < d.bufferLength; i++ {
+		d.buffer[i] = 0xFF
+	}
+
+	d.cs.Low()
+	d.dc.Low()
+	d.rst.Low()
+
+	d.Reset()
+
+	d.SendCommand(DRIVER_OUTPUT_CONTROL)
+	d.SendData(uint8((d.height - 1) & 0xFF))
+	d.SendData(uint8(((d.height - 1) >> 8) & 0xFF))
+	d.SendData(0x00) // GD = 0; SM = 0; TB = 0;
+	d.SendCommand(BOOSTER_SOFT_START_CONTROL)
+	d.SendData(0xD7)
+	d.SendData(0xD6)
+	d.SendData(0x9D)
+	d.SendCommand(WRITE_VCOM_REGISTER)
+	d.SendData(0xA8) // VCOM 7C
+	d.SendCommand(SET_DUMMY_LINE_PERIOD)
+	d.SendData(0x1A) // 4 dummy lines per gate
+	d.SendCommand(SET_GATE_TIME)
+	d.SendData(0x08) // 2us per line
+	d.SendCommand(DATA_ENTRY_MODE_SETTING)
+	d.SendData(0x03) // X increment; Y increment
+
+	d.SetLUT(true)
+}
+
+// Reset resets the device
+func (d *Device) Reset() {
+	d.rst.Low()
+	time.Sleep(200 * time.Millisecond)
+	d.rst.High()
+	time.Sleep(200 * time.Millisecond)
+}
+
+// DeepSleep puts the display into deepsleep
+func (d *Device) DeepSleep() {
+	d.SendCommand(DEEP_SLEEP_MODE)
+	d.WaitUntilIdle()
+}
+
+// SendCommand sends a command to the display
+func (d *Device) SendCommand(command uint8) {
+	d.sendDataCommand(true, command)
+}
+
+// SendData sends a data byte to the display
+func (d *Device) SendData(data uint8) {
+	d.sendDataCommand(false, data)
+}
+
+// sendDataCommand sends image data or a command to the screen
+func (d *Device) sendDataCommand(isCommand bool, data uint8) {
+	if isCommand {
+		d.dc.Low()
+	} else {
+		d.dc.High()
+	}
+	d.cs.Low()
+	d.bus.Transfer(data)
+	d.cs.High()
+}
+
+// SetLUT sets the look up tables for full or partial updates
+func (d *Device) SetLUT(fullUpdate bool) {
+	d.SendCommand(WRITE_LUT_REGISTER)
+	if fullUpdate {
+		for i := 0; i < 30; i++ {
+			d.SendData(lutFullUpdate[i])
+		}
+	} else {
+		for i := 0; i < 30; i++ {
+			d.SendData(lutPartialUpdate[i])
+		}
+	}
+}
+
+// SetPixel modifies the internal buffer in a single pixel.
+// The display have 2 colors: black and white
+// We use RGBA(0,0,0, 255) as white (transparent)
+// Anything else as black
+func (d *Device) SetPixel(x int16, y int16, c color.RGBA) {
+	if x < 0 || x >= d.width || y < 0 || y >= d.height {
+		return
+	}
+	byteIndex := (x + y*d.width) / 8
+	if c.R == 0 && c.G == 0 && c.B == 0 { // TRANSPARENT / WHITE
+		d.buffer[byteIndex] |= 0x80 >> uint8(x%8)
+	} else { // WHITE / EMPTY
+		d.buffer[byteIndex] &^= 0x80 >> uint8(x%8)
+	}
+}
+
+// Display sends the buffer to the screen.
+func (d *Device) Display() error {
+	d.setMemoryArea(0, 0, d.width-1, d.height-1)
+	for j := int16(0); j < d.height; j++ {
+		d.setMemoryPointer(0, j)
+		d.SendCommand(WRITE_RAM)
+		for i := int16(0); i < d.width/8; i++ {
+			d.SendData(d.buffer[i+j*(d.width/8)])
+		}
+	}
+
+	d.SendCommand(DISPLAY_UPDATE_CONTROL_2)
+	d.SendData(0xC4)
+	d.SendCommand(MASTER_ACTIVATION)
+	d.SendCommand(TERMINATE_FRAME_READ_WRITE)
+	return nil
+}
+
+// DisplayRect sends only an area of the buffer to the screen.
+func (d *Device) DisplayRect(x int16, y int16, width int16, height int16) error {
+	if x < 0 || y < 0 || x >= d.width || y >= d.height || width < 0 || height < 0 {
+		return errors.New("wrong rectangle")
+	}
+	x &= 0xF8
+	width &= 0xF8
+	width = x + width // reuse variables
+	if width >= d.width {
+		width = d.width
+	}
+	height = y + height
+	if height > d.height {
+		height = d.height
+	}
+	d.setMemoryArea(x, y, width, height)
+	x = x / 8
+	width = width / 8
+	for ; y < height; y++ {
+		d.setMemoryPointer(8*x, y)
+		d.SendCommand(WRITE_RAM)
+		for i := int16(x); i < width; i++ {
+			d.SendData(d.buffer[i+y*d.width/8])
+		}
+	}
+
+	d.SendCommand(DISPLAY_UPDATE_CONTROL_2)
+	d.SendData(0xC4)
+	d.SendCommand(MASTER_ACTIVATION)
+	d.SendCommand(TERMINATE_FRAME_READ_WRITE)
+	return nil
+}
+
+// ClearDisplay erases the device SRAM
+func (d *Device) ClearDisplay() {
+	d.setMemoryArea(0, 0, d.width-1, d.height-1)
+	d.setMemoryPointer(0, 0)
+	d.SendCommand(WRITE_RAM)
+	for i := uint32(0); i < d.bufferLength; i++ {
+		d.SendData(0xFF)
+	}
+	d.Display()
+}
+
+// setMemoryArea sets the area of the display that will be updated
+func (d *Device) setMemoryArea(x0 int16, y0 int16, x1 int16, y1 int16) {
+	d.SendCommand(SET_RAM_X_ADDRESS_START_END_POSITION)
+	d.SendData(uint8((x0 >> 3) & 0xFF))
+	d.SendData(uint8((x1 >> 3) & 0xFF))
+	d.SendCommand(SET_RAM_Y_ADDRESS_START_END_POSITION)
+	d.SendData(uint8(y0 & 0xFF))
+	d.SendData(uint8((y0 >> 8) & 0xFF))
+	d.SendData(uint8(y1 & 0xFF))
+	d.SendData(uint8((y1 >> 8) & 0xFF))
+}
+
+// setMemoryPointer moves the internal pointer to the speficied coordinates
+func (d *Device) setMemoryPointer(x int16, y int16) {
+	d.SendCommand(SET_RAM_X_ADDRESS_COUNTER)
+	d.SendData(uint8((x >> 3) & 0xFF))
+	d.SendCommand(SET_RAM_Y_ADDRESS_COUNTER)
+	d.SendData(uint8(y & 0xFF))
+	d.SendData(uint8((y >> 8) & 0xFF))
+	d.WaitUntilIdle()
+}
+
+// WaitUntilIdle waits until the display is ready
+func (d *Device) WaitUntilIdle() {
+	for d.busy.Get() {
+		time.Sleep(100 * time.Millisecond)
+	}
+}
+
+// IsBusy returns the busy status of the display
+func (d *Device) IsBusy() bool {
+	return d.busy.Get()
+}
+
+// ClearBuffer sets the buffer to 0xFF (white)
+func (d *Device) ClearBuffer() {
+	for i := uint32(0); i < d.bufferLength; i++ {
+		d.buffer[i] = 0xFF
+	}
+}
+
+// Size returns the current size of the display.
+func (d *Device) Size() (w, h int16) {
+	return d.width, d.height
+}
@@ -0,0 +1,26 @@
+package epd2in13
+
+// Registers
+const (
+	DRIVER_OUTPUT_CONTROL                = 0x01
+	BOOSTER_SOFT_START_CONTROL           = 0x0C
+	GATE_SCAN_START_POSITION             = 0x0F
+	DEEP_SLEEP_MODE                      = 0x10
+	DATA_ENTRY_MODE_SETTING              = 0x11
+	SW_RESET                             = 0x12
+	TEMPERATURE_SENSOR_CONTROL           = 0x1A
+	MASTER_ACTIVATION                    = 0x20
+	DISPLAY_UPDATE_CONTROL_1             = 0x21
+	DISPLAY_UPDATE_CONTROL_2             = 0x22
+	WRITE_RAM                            = 0x24
+	WRITE_VCOM_REGISTER                  = 0x2C
+	WRITE_LUT_REGISTER                   = 0x32
+	SET_DUMMY_LINE_PERIOD                = 0x3A
+	SET_GATE_TIME                        = 0x3B
+	BORDER_WAVEFORM_CONTROL              = 0x3C
+	SET_RAM_X_ADDRESS_START_END_POSITION = 0x44
+	SET_RAM_Y_ADDRESS_START_END_POSITION = 0x45
+	SET_RAM_X_ADDRESS_COUNTER            = 0x4E
+	SET_RAM_Y_ADDRESS_COUNTER            = 0x4F
+	TERMINATE_FRAME_READ_WRITE           = 0xFF
+)