395 lines
10 KiB
Go
395 lines
10 KiB
Go
package spi
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import (
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"fmt"
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"image"
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"time"
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"gobot.io/x/gobot/v2"
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"gobot.io/x/gobot/v2/drivers/gpio"
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)
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const (
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// default values
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ssd1306Width = 128
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ssd1306Height = 64
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ssd1306DcPin = "16" // for raspberry pi
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ssd1306RstPin = "18" // for raspberry pi
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ssd1306ExternalVcc = false
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ssd1306SetStartLine = 0x40
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// fundamental commands
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ssd1306SetContrast = 0x81
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ssd1306DisplayOnResumeToRAM = 0xA4
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ssd1306DisplayOnResume = 0xA5
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ssd1306SetDisplayNormal = 0xA6
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ssd1306SetDisplayInverse = 0xA7
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ssd1306SetDisplayOff = 0xAE
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ssd1306SetDisplayOn = 0xAF
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// scrolling commands
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ssd1306RightHorizontalScroll = 0x26
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ssd1306LeftHorizontalScroll = 0x27
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ssd1306VerticalAndRightHorizontalScroll = 0x29
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ssd1306VerticalAndLeftHorizontalScroll = 0x2A
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ssd1306DeactivateScroll = 0x2E
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ssd1306ActivateScroll = 0x2F
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ssd1306SetVerticalScrollArea = 0xA3
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// addressing settings commands
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ssd1306SetMemoryAddressingMode = 0x20
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ssd1306ColumnAddr = 0x21
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ssd1306PageAddr = 0x22
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// hardware configuration commands
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ssd1306SetSegmentRemap0 = 0xA0
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ssd1306SetSegmentRemap127 = 0xA1
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ssd1306SetMultiplexRatio = 0xA8
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ssd1306ComScanInc = 0xC0
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ssd1306ComScanDec = 0xC8
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ssd1306SetDisplayOffset = 0xD3
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ssd1306SetComPins = 0xDA
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// timing and driving scheme commands
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ssd1306SetDisplayClock = 0xD5
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ssd1306SetPrechargePeriod = 0xD9
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ssd1306SetVComDeselectLevel = 0xDB
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ssd1306NOOP = 0xE3
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// charge pump command
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ssd1306ChargePumpSetting = 0x8D
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)
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// DisplayBuffer represents the display buffer intermediate memory
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type DisplayBuffer struct {
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width, height, pageSize int
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buffer []byte
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}
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// NewDisplayBuffer creates a new DisplayBuffer
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func NewDisplayBuffer(width, height, pageSize int) *DisplayBuffer {
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s := &DisplayBuffer{
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width: width,
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height: height,
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pageSize: pageSize,
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}
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s.buffer = make([]byte, s.Size())
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return s
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}
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// Size returns the memory size of the display buffer
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func (d *DisplayBuffer) Size() int {
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return (d.width * d.height) / d.pageSize
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}
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// Clear the contents of the display buffer
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func (d *DisplayBuffer) Clear() {
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d.buffer = make([]byte, d.Size())
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}
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// SetPixel sets the x, y pixel with c color
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func (d *DisplayBuffer) SetPixel(x, y, c int) {
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idx := x + (y/d.pageSize)*d.width
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bit := uint(y) % uint(d.pageSize)
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if c == 0 {
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d.buffer[idx] &= ^(1 << bit)
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} else {
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d.buffer[idx] |= (1 << bit)
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}
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}
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// Set sets the display buffer with the given buffer
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func (d *DisplayBuffer) Set(buf []byte) {
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d.buffer = buf
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}
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// SSD1306Driver is a Gobot Driver for a SSD1306 Display
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type SSD1306Driver struct {
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*Driver
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dcDriver *gpio.DirectPinDriver
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rstDriver *gpio.DirectPinDriver
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pageSize int
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DisplayWidth int
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DisplayHeight int
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DCPin string
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RSTPin string
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ExternalVcc bool
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buffer *DisplayBuffer
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}
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// NewSSD1306Driver creates a new SSD1306Driver.
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//
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// Params:
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//
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// conn Connector - the Adaptor to use with this Driver
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//
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// Optional params:
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//
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// spi.WithBusNumber(int): bus to use with this driver
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// spi.WithChipNumber(int): chip to use with this driver
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// spi.WithMode(int): mode to use with this driver
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// spi.WithBitCount(int): number of bits to use with this driver
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// spi.WithSpeed(int64): speed in Hz to use with this driver
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// spi.WithDisplayWidth(int): width of display (defaults to 128)
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// spi.WithDisplayHeight(int): height of display (defaults to 64)
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// spi.WithDCPin(string): gpio pin number connected to dc pin on display (defaults to "16")
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// spi.WithRstPin(string): gpio pin number connected to rst pin on display (defaults to "18")
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// spi.WithExternalVCC(bool): set to true if using external vcc (defaults to false)
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func NewSSD1306Driver(a gobot.Adaptor, options ...func(Config)) *SSD1306Driver {
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// cast adaptor to spi connector since we also need the adaptor for gpio
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b, ok := a.(Connector)
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if !ok {
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panic("unable to get gobot connector for ssd1306")
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}
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s := &SSD1306Driver{
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Driver: NewDriver(b, "SSD1306"),
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DisplayWidth: ssd1306Width,
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DisplayHeight: ssd1306Height,
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DCPin: ssd1306DcPin,
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RSTPin: ssd1306RstPin,
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ExternalVcc: ssd1306ExternalVcc,
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}
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s.afterStart = s.initialize
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s.beforeHalt = s.shutdown
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for _, option := range options {
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option(s)
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}
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s.dcDriver = gpio.NewDirectPinDriver(a, s.DCPin)
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s.rstDriver = gpio.NewDirectPinDriver(a, s.RSTPin)
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s.pageSize = s.DisplayHeight / 8
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s.buffer = NewDisplayBuffer(s.DisplayWidth, s.DisplayHeight, s.pageSize)
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s.AddCommand("Display", func(params map[string]interface{}) interface{} {
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err := s.Display()
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return map[string]interface{}{"err": err}
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})
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s.AddCommand("On", func(params map[string]interface{}) interface{} {
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err := s.On()
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return map[string]interface{}{"err": err}
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})
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s.AddCommand("Off", func(params map[string]interface{}) interface{} {
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err := s.Off()
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return map[string]interface{}{"err": err}
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})
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s.AddCommand("Clear", func(params map[string]interface{}) interface{} {
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err := s.Clear()
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return map[string]interface{}{"err": err}
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})
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s.AddCommand("SetContrast", func(params map[string]interface{}) interface{} {
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contrast := byte(params["contrast"].(byte))
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err := s.SetContrast(contrast)
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return map[string]interface{}{"err": err}
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})
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s.AddCommand("Set", func(params map[string]interface{}) interface{} {
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x := int(params["x"].(int))
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y := int(params["y"].(int))
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c := int(params["c"].(int))
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s.Set(x, y, c)
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return nil
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})
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return s
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}
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// WithDisplayWidth option sets the SSD1306Driver DisplayWidth option.
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func WithDisplayWidth(val int) func(Config) {
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return func(c Config) {
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d, ok := c.(*SSD1306Driver)
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if ok {
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d.DisplayWidth = val
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} else {
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panic("unable to set display width for ssd1306")
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}
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}
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}
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// WithDisplayHeight option sets the SSD1306Driver DisplayHeight option.
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func WithDisplayHeight(val int) func(Config) {
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return func(c Config) {
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d, ok := c.(*SSD1306Driver)
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if ok {
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d.DisplayHeight = val
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} else {
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panic("unable to set display height for ssd1306")
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}
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}
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}
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// WithDCPin option sets the SSD1306Driver DC Pin option.
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func WithDCPin(val string) func(Config) {
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return func(c Config) {
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d, ok := c.(*SSD1306Driver)
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if ok {
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d.DCPin = val
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} else {
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panic("unable to set dc pin for ssd1306")
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}
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}
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}
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// WithRstPin option sets the SSD1306Driver RST pin option.
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func WithRstPin(val string) func(Config) {
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return func(c Config) {
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d, ok := c.(*SSD1306Driver)
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if ok {
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d.RSTPin = val
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} else {
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panic("unable to set rst pin for ssd1306")
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}
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}
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}
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// WithExternalVCC option sets the SSD1306Driver external vcc option.
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func WithExternalVCC(val bool) func(Config) {
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return func(c Config) {
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d, ok := c.(*SSD1306Driver)
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if ok {
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d.ExternalVcc = val
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} else {
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panic("unable to set rst pin for ssd1306")
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}
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}
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}
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// On turns on the display.
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func (s *SSD1306Driver) On() error {
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return s.command(ssd1306SetDisplayOn)
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}
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// Off turns off the display.
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func (s *SSD1306Driver) Off() error {
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return s.command(ssd1306SetDisplayOff)
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}
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// Clear clears the display buffer.
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func (s *SSD1306Driver) Clear() error {
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s.buffer.Clear()
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return nil
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}
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// Set sets a pixel in the display buffer.
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func (s *SSD1306Driver) Set(x, y, c int) {
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s.buffer.SetPixel(x, y, c)
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}
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// Reset re-initializes the device to a clean state.
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func (s *SSD1306Driver) Reset() error {
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s.rstDriver.DigitalWrite(1)
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time.Sleep(10 * time.Millisecond)
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s.rstDriver.DigitalWrite(0)
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time.Sleep(10 * time.Millisecond)
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s.rstDriver.DigitalWrite(1)
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return nil
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}
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// SetBufferAndDisplay sets the display buffer with the given buffer and displays the image.
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func (s *SSD1306Driver) SetBufferAndDisplay(buf []byte) error {
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s.buffer.Set(buf)
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return s.Display()
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}
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// SetContrast sets the display contrast (0-255).
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func (s *SSD1306Driver) SetContrast(contrast byte) error {
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if err := s.command(ssd1306SetContrast); err != nil {
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return err
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}
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return s.command(contrast)
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}
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// Display sends the memory buffer to the display.
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func (s *SSD1306Driver) Display() error {
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s.command(ssd1306ColumnAddr)
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s.command(0)
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s.command(uint8(s.DisplayWidth) - 1)
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s.command(ssd1306PageAddr)
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s.command(0)
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s.command(uint8(s.pageSize) - 1)
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if err := s.dcDriver.DigitalWrite(1); err != nil {
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return err
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}
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return s.connection.WriteBlockData(0x40, s.buffer.buffer)
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}
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// ShowImage takes a standard Go image and shows it on the display in monochrome.
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func (s *SSD1306Driver) ShowImage(img image.Image) error {
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if img.Bounds().Dx() != s.DisplayWidth || img.Bounds().Dy() != s.DisplayHeight {
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return fmt.Errorf("Image must match the display width and height")
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}
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s.Clear()
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for y, w, h := 0, img.Bounds().Dx(), img.Bounds().Dy(); y < h; y++ {
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for x := 0; x < w; x++ {
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c := img.At(x, y)
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if r, g, b, _ := c.RGBA(); r > 0 || g > 0 || b > 0 {
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s.Set(x, y, 1)
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}
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}
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}
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return s.Display()
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}
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// command sends a unique command
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func (s *SSD1306Driver) command(b byte) error {
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if err := s.dcDriver.DigitalWrite(0); err != nil {
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return err
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}
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return s.connection.WriteByte(b)
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}
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// initialize configures the ssd1306 based on the options passed in when the driver was created
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func (s *SSD1306Driver) initialize() error {
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s.command(ssd1306SetDisplayOff)
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s.command(ssd1306SetDisplayClock)
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if s.DisplayHeight == 16 {
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s.command(0x60)
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} else {
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s.command(0x80)
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}
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s.command(ssd1306SetMultiplexRatio)
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s.command(uint8(s.DisplayHeight) - 1)
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s.command(ssd1306SetDisplayOffset)
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s.command(0x0)
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s.command(ssd1306SetStartLine)
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s.command(0x0)
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s.command(ssd1306ChargePumpSetting)
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if s.ExternalVcc {
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s.command(0x10)
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} else {
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s.command(0x14)
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}
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s.command(ssd1306SetMemoryAddressingMode)
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s.command(0x00)
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s.command(ssd1306SetSegmentRemap0)
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s.command(0x01)
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s.command(ssd1306ComScanInc)
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s.command(ssd1306SetComPins)
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if s.DisplayHeight == 64 {
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s.command(0x12)
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} else {
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s.command(0x02)
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}
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s.command(ssd1306SetContrast)
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if s.DisplayHeight == 64 {
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if s.ExternalVcc {
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s.command(0x9F)
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} else {
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s.command(0xCF)
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}
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} else {
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s.command(0x8F)
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}
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s.command(ssd1306SetPrechargePeriod)
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if s.ExternalVcc {
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s.command(0x22)
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} else {
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s.command(0xF1)
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}
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s.command(ssd1306SetVComDeselectLevel)
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s.command(0x40)
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s.command(ssd1306DisplayOnResumeToRAM)
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s.command(ssd1306SetDisplayNormal)
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s.command(ssd1306DeactivateScroll)
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s.command(ssd1306SetDisplayOn)
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return nil
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}
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func (s *SSD1306Driver) shutdown() error {
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s.Reset()
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s.Off()
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return nil
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}
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