LCD1602

What you need

Circuit

Tips

Code

main.swift

import SwiftIO

let i2c = I2C(Id.I2C0)
let lcd = LCD1602(i2c)

lcd.write(x: 0, y: 0, "Hello World!")

while true {

}

LCD1602.swift

import SwiftIO

final class LCD1602 {

    private enum Command {
        static let clearDisplay: UInt8 = 0x01
        static let returnHome: UInt8 = 0x02
        static let entryModeSet: UInt8 = 0x04
        static let displayControl: UInt8 = 0x08
        static let cursorShift: UInt8 = 0x10
        static let functionSet: UInt8 = 0x20
        static let setCGRAMAddr: UInt8 = 0x40
        static let setDDRAMAddr: UInt8 = 0x80
    }

    private enum EntryMode {
        static let entryRight: UInt8 = 0x00
        static let entryLeft: UInt8 = 0x02
        static let entryShiftIncrement: UInt8 = 0x01
        static let entryShiftDecrement: UInt8 = 0x00
    }

    private enum Control {
        static let displayOn: UInt8 = 0x04
        static let displayOff: UInt8 = 0x00
        static let cursorOn: UInt8 = 0x02
        static let cursorOff: UInt8 = 0x00
        static let blinkOn: UInt8 = 0x01
        static let blinkOff: UInt8 = 0x00
    }

    private enum Shift {
        static let displayMove: UInt8 = 0x08
        static let cursorMove: UInt8 = 0x00
        static let moveRight: UInt8 = 0x04
        static let moveLeft: UInt8 = 0x00
    }

    private enum Mode {
        static let _8BitMode: UInt8 = 0x10
        static let _4BitMode: UInt8 = 0x00
        static let _2Line: UInt8 = 0x08
        static let _1Line: UInt8 = 0x00
        static let _5x10Dots: UInt8 = 0x04
        static let _5x8Dots: UInt8 = 0x00
    }

      let address: UInt8 = 0x3E

      let i2c: I2C

      var displayFunctionState: UInt8
      var displayControlState: UInt8
      var displayModeState: UInt8
      var numLines: UInt8
      var currLine: UInt8


      convenience init(_ i2c: I2C) {
          self.init(i2c, 16, 2, 0)
    }

      init(_ i2c: I2C, _ cols: UInt8, _ rows: UInt8, _ dotSize: UInt8) {
          self.i2c = i2c

          displayFunctionState = 0
          displayControlState = 0
          displayModeState = 0

          if rows > 1 {
              displayFunctionState |= Mode._2Line
        }

          numLines = rows
          currLine = 0

          if dotSize != 0 && rows == 1 {
              displayFunctionState |= Mode._5x10Dots
        }

          writeCommand(Command.functionSet | displayFunctionState)
          wait(us: 4500)

          writeCommand(Command.functionSet | displayFunctionState)
          wait(us: 150)

          writeCommand(Command.functionSet | displayFunctionState)
          writeCommand(Command.functionSet | displayFunctionState)

          displayControlState =     Control.displayOn | Control.cursorOff | Control.blinkOff
          turnOn()

          clear()

          displayModeState = EntryMode.entryLeft | EntryMode.entryShiftDecrement
          writeCommand(Command.entryModeSet | displayModeState)
    }


      func turnOn() {
          displayControlState |= Control.displayOn
          writeCommand(Command.displayControl | displayControlState)
    }

      func turnOff() {
          displayControlState &= ~Control.displayOn;
          writeCommand(Command.displayControl | displayControlState)
    }

      func clear() {
          writeCommand(Command.clearDisplay)
          wait(us: 2000)
    }

    func home() {
        writeCommand(Command.returnHome)
        wait(us: 2000)
    }

    func noCursor() {
        displayControlState &= ~Control.cursorOn
        writeCommand(Command.displayControl | displayControlState)
    }

    func cursor() {
        displayControlState |= Control.cursorOn
        writeCommand(Command.displayControl | displayControlState)
    }

    func noBlink() {
        displayControlState &= ~Control.blinkOn
        writeCommand(Command.displayControl | displayControlState)
    }

    func blink() {
        displayControlState |= Control.blinkOn
        writeCommand(Command.displayControl | displayControlState)
    }

    func scrollLeft() {
          writeCommand(Command.cursorShift | Shift.displayMove | Shift.moveLeft)
    }

      func scrollRight() {
          writeCommand(Command.cursorShift | Shift.displayMove | Shift.moveRight)
    }

    func leftToRight() {
        displayModeState |= EntryMode.entryLeft
        writeCommand(Command.entryModeSet | displayModeState)
    }

    func rightToLeft() {
        displayModeState &= ~EntryMode.entryLeft
        writeCommand(Command.entryModeSet | displayModeState)
    }

    func autoScroll() {
        displayModeState |= EntryMode.entryShiftIncrement
        writeCommand(Command.entryModeSet | displayModeState)
    }

    func noAutoScroll() {
        displayModeState &= ~EntryMode.entryShiftIncrement
        writeCommand(Command.entryModeSet | displayModeState)
    }

      func writeCommand(_ value: UInt8) {
        let data: [UInt8] = [0x80, value]
          i2c.write(data, to: address)
    }

    func clear(x: Int, y: Int, _ count: Int) {
        let data: [UInt8] = [0x40, 0x20]

        setCursor(x: x, y: y)
        for _ in 1...count {
            i2c.write(data, to: address)
        }
        setCursor(x: x, y: y)
    }

      func setCursor(x: Int, y: Int) {
          let val: UInt8 = y == 0 ? UInt8(x) | 0x80 : UInt8(x) | 0xc0
          writeCommand(val)
    }

      func write(_ str: String) {
          let array: [UInt8] = Array(str.utf8)
          var data: [UInt8] = [0x40, 0]    

          for item in array {
              data[1] = UInt8(item)
              i2c.write(data, to: address)
        }
    }

    func write(x: Int, y: Int, _ num: Int) {
        write(x: x, y: y, String(num))
    }

      func write(x: Int, y: Int, _ str: String) {
          setCursor(x: x, y: y)
          write(str)
    }
}

Video

See Also

References

Last revision 2020/09/10 by Johnson