func (display *HD44780) pulseEnable(data byte) {
display.expanderWrite(data | display.en) // En high
hwio.DelayMicroseconds(1) // enable pulse must be >450ns
display.expanderWrite(data & ^display.en) // En low
hwio.DelayMicroseconds(50) // commands need > 37us to settle
}
func (display *HD44780) Init(cols int, lines int) {
display.displayFunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS
if lines > 1 {
display.displayFunction |= LCD_2LINE
}
display.numLines = lines
// for some 1 line displays you can select a 10 pixel high font
// if (dotsize != 0) && (lines == 1) {
// _displayfunction |= LCD_5x10DOTS
// }
// SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION!
// according to datasheet, we need at least 40ms after power rises above 2.7V
// before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50
hwio.DelayMicroseconds(50000)
// Now we pull both RS and R/W low to begin commands
display.backlight = display.bl
display.expanderWrite(display.backlight) // reset expander and turn backlight off (Bit 8 =1)
hwio.Delay(1000)
//put the LCD into 4 bit mode
// this is according to the hitachi HD44780 datasheet
// figure 24, pg 46
// we start in 8bit mode, try to set 4 bit mode
display.write4bits(0x03, 0)
hwio.DelayMicroseconds(4500) // wait min 4.1ms
// // second try
display.write4bits(0x03, 0)
hwio.DelayMicroseconds(4500) // wait min 4.1ms
// // third go!
display.write4bits(0x03, 0)
hwio.DelayMicroseconds(150)
// // finally, set to 4-bit interface
display.write4bits(0x02, 0)
// set # lines, font size, etc.
display.Command(LCD_FUNCTIONSET | display.displayFunction)
// turn the display on with no cursor or blinking default
display.displayControl = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF
display.Display()
// clear it off
display.Clear()
// Initialize to default text direction (for roman languages)
display.displayMode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT
// set the entry mode
display.Command(LCD_ENTRYMODESET | display.displayMode)
display.Home()
}
func (display *HD44780) Home() {
display.Command(LCD_RETURNHOME) // set cursor position to zero
hwio.DelayMicroseconds(2000) // this command takes a long time!
}
func (display *HD44780) Clear() {
display.Command(LCD_CLEARDISPLAY) // clear display, set cursor position to zero
hwio.DelayMicroseconds(2000) // this command takes a long time!
}