feat(0.1.0)

index.mjs

@@ -0,0 +1,141 @@
+import i2c from 'i2c-bus';
+
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms))
+}
+
+const ROW_OFFSET = [0x00, 0x40, 0x14, 0x54]
+
+export class LCD {
+  font_size = 8
+  lines = 2
+  backlight = true
+
+  #device
+  #addr
+  #bus
+
+  constructor (device, addr) {
+    this.#device = device
+    this.#addr = addr
+  }
+
+  async open() {
+    this.#bus = await i2c.openPromisified(this.#device)
+
+    for (let i = 0; i < 3; i++) {
+      await this.sendByte(0x30)
+      await sleep(1)
+    }
+
+    await this.sendByte(0x20)
+    await sleep(1)
+
+    await this.send(LCD.FunctionSet(4, this.lines, this.font_size))
+    await this.send(LCD.DisplayOnOff(true, false, false))
+    await this.send(LCD.EntryModeSet('right', false))
+    await this.send(LCD.ClearDisplay())
+  }
+
+  async sendString(str) {
+    for (let i = 0; i < str.length; i++) {
+      await this.send(LCD.WriteData(str.charCodeAt(i)))
+    }
+  }
+
+  async jump(col, row) {
+    col %= 20
+    row = ROW_OFFSET[row % 4]
+
+    await this.send(LCD.SetDDRamAddr(row | col))
+  }
+
+  async close() {
+    await this.#bus.close()
+  }
+
+  //RS RW D7 D6 D5 D4 D3 D2 D1 D0
+  //D7 D6 D5 D4 BL EN RW RS
+  async send(instruction) {
+    const RS  = (instruction.value & 0x200) >>> 9
+    const BL  = (this.backlight ? 1 : 0) << 3
+    const RW  = (instruction.value & 0x100) >>> 7
+    const D74 = (instruction.value & 0x0F0)
+    const D30 = (instruction.value & 0x00F) << 4
+
+    await this.sendByte(D74 | BL | RS | RW)
+    await this.sendByte(D30 | BL | RS | RW)
+    await sleep(instruction.delay)
+  }
+
+  async sendByte(byte) {
+    await this.writeByte(byte)
+    await this.writeByte(byte | 4)
+    await this.writeByte(byte)
+  }
+
+  async writeByte(byte) {
+    await this.#bus.i2cWrite(this.#addr, 1, Buffer.from([byte]))
+  }
+}
+
+Object.defineProperties(LCD, {
+  ClearDisplay: { value: function() {
+    return {
+      value: 0x1,
+      delay: 2,
+    }
+  } },
+  EntryModeSet: { value: function(direction, display_shift) {
+    const I_Direction = (direction == 'right' ? 1 : 0) << 1
+    const Shift = (display_shift ? 1 : 0)
+
+    return {
+      value: 0x4 | I_Direction | Shift,
+      delay: 1,
+    }
+  } },
+  DisplayOnOff: { value: function(display, cursor, cursor_position) {
+    const Display = (display ? 1 : 0) << 2
+    const Cursor = (cursor ? 1 : 0) << 1
+    const Cursor_Position = (cursor_position ? 1 : 0)
+
+    return {
+      value: 0x8 | Display | Cursor | Cursor_Position,
+      delay: 1,
+    }
+  } },
+  CursorDisplayShift: { value: function(target, direction) {
+    const Screen_Cursor = (target == 'display' ? 1 : 0) << 3
+    const Right_Left = (direction == 'right' ? 1 : 0) << 2
+
+    return {
+      value: 0x10 | Screen_Cursor | Right_Left,
+      delay: 1,
+    }
+  } },
+  FunctionSet: { value: function(data_length, number_of_lines, font_size) {
+    const Data_Length = (data_length == 8 ? 1 : 0) << 4
+    const Number_of_lines = (number_of_lines == 2 ? 1 : 0) << 3
+    const Font_size = (font_size == 11 ? 1 : 0) << 2
+
+    return {
+      value: 0x20 | Data_Length | Number_of_lines | Font_size,
+      delay: 1,
+    }
+  } },
+  SetDDRamAddr: { value: function(address) {
+    address &= 0x7F
+    return {
+      value: 0x80 | address,
+      delay: 1,
+    }
+  } },
+  WriteData: { value: function(byte) {
+    byte &= 0xFF
+    return {
+      value: 0x200 | byte,
+      delay: 1,
+    }
+  } },
+})