clean commit, added smoke tests

pcd8544/pcd8544.go

@@ -0,0 +1,150 @@
+// Package pcd8544 implements a driver for the PCD8544 48x84 pixels matrix LCD, used in Nokia's 5110 and 3310 phones.
+//
+// Datasheet: http://eia.udg.edu/~forest/PCD8544_1.pdf
+package pcd8544
+
+import (
+	"errors"
+	"image/color"
+	"machine"
+	"time"
+)
+
+// Device wraps an SPI connection.
+type Device struct {
+	bus        machine.SPI
+	dcPin      machine.GPIO
+	rstPin     machine.GPIO
+	scePin     machine.GPIO
+	buffer     []byte
+	width      int16
+	height     int16
+	bufferSize int16
+}
+
+type Config struct {
+	Width  int16
+	Height int16
+}
+
+// New creates a new PCD8544 connection. The SPI bus must already be configured.
+func New(bus machine.SPI, dcPin machine.GPIO, rstPin machine.GPIO, scePin machine.GPIO) *Device {
+	return &Device{
+		bus:    bus,
+		dcPin:  dcPin,
+		rstPin: rstPin,
+		scePin: scePin,
+	}
+}
+
+// Configure initializes the display with default configuration
+func (d *Device) Configure(cfg Config) {
+	if cfg.Width != 0 {
+		d.width = cfg.Width
+	} else {
+		d.width = 84
+	}
+	if cfg.Height != 0 {
+		d.height = cfg.Height
+	} else {
+		d.height = 48
+	}
+	d.bufferSize = d.width * d.height / 8
+	d.buffer = make([]byte, d.bufferSize)
+
+	d.rstPin.Low()
+	time.Sleep(100 * time.Nanosecond)
+	d.rstPin.High()
+	d.SendCommand(FUNCTIONSET | EXTENDEDINSTRUCTION) // H = 1
+	d.SendCommand(SETVOP | 0x3f)                     // 0x3f : Vop6 = 0, Vop5 to Vop0 = 1
+	d.SendCommand(SETTEMP | 0x03)                    // Experimentally determined
+	d.SendCommand(SETBIAS | 0x03)                    // Experimentally determined
+	d.SendCommand(FUNCTIONSET)                       // H = 0
+	d.SendCommand(DISPLAYCONTROL | DISPLAYNORMAL)
+}
+
+// ClearBuffer clears the image buffer
+func (d *Device) ClearBuffer() {
+	d.buffer = make([]byte, d.bufferSize)
+}
+
+// ClearDisplay clears the image buffer and clear the display
+func (d *Device) ClearDisplay() {
+	d.ClearBuffer()
+	d.Display()
+}
+
+// Display sends the whole buffer to the screen
+func (d *Device) Display() error {
+	d.SendCommand(FUNCTIONSET) // H = 0
+	d.SendCommand(SETXADDR)
+	d.SendCommand(SETYADDR)
+
+	for i := int16(0); i < d.bufferSize; i++ {
+		d.SendData(d.buffer[i])
+	}
+	return nil
+}
+
+// sendDataCommand sends image data or a command to the screen
+func (d *Device) sendDataCommand(isCommand bool, data uint8) {
+	if isCommand {
+		d.dcPin.Low()
+	} else {
+		d.dcPin.High()
+	}
+	d.scePin.Low()
+	d.bus.Transfer(data)
+	d.scePin.High()
+}
+
+// SetPixel enables or disables a pixel in the buffer
+// color.RGBA{0, 0, 0, 255} is consider transparent, anything else
+// with enable a pixel on the screen
+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/8)*d.width
+	if c.R != 0 || c.G != 0 || c.B != 0 {
+		d.buffer[byteIndex] |= 1 << uint8(y%8)
+	} else {
+		d.buffer[byteIndex] &^= 1 << uint8(y%8)
+	}
+}
+
+// GetPixel returns if the specified pixel is on (true) or off (false)
+func (d *Device) GetPixel(x int16, y int16) bool {
+	if x < 0 || x >= d.width || y < 0 || y >= d.height {
+		return false
+	}
+	byteIndex := x + (y/8)*d.width
+	return (d.buffer[byteIndex] >> uint8(y%8) & 0x1) == 1
+}
+
+// SetBuffer changes the whole buffer at once
+func (d *Device) SetBuffer(buffer []byte) error {
+	if int16(len(buffer)) != d.bufferSize {
+		//return ErrBuffer
+		return errors.New("Wrong size buffer")
+	}
+	for i := int16(0); i < d.bufferSize; i++ {
+		d.buffer[i] = buffer[i]
+	}
+	return nil
+}
+
+// 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)
+}
+
+// Size returns the current size of the display.
+func (d *Device) Size() (w, h int16) {
+	return d.width, d.height
+}

pcd8544/registers.go

@@ -0,0 +1,21 @@
+package pcd8544
+
+// Registers
+const (
+	POWERDOWN           = 0x04
+	ENTRYMODE           = 0x02
+	EXTENDEDINSTRUCTION = 0x01
+	FUNCTIONSET         = 0x20
+
+	DISPLAYCONTROL  = 0x08
+	DISPLAYBLANK    = 0x0
+	DISPLAYNORMAL   = 0x04
+	DISPLAYALLON    = 0x01
+	DISPLAYINVERTED = 0x05
+
+	SETYADDR = 0x40
+	SETXADDR = 0x80
+	SETTEMP  = 0x04
+	SETBIAS  = 0x10
+	SETVOP   = 0x80
+)