The Hitachi-compatible LCDs can be controlled in two modes: 4-bit or 8-bit. The LiquidCrystal Library simplifies this for you so you don't need to know the low-level instructions.
The process of controlling the display involves putting the data that form the image of what you want to display into the data registers, then putting instructions in the instruction register. There's also a display contrast pin (Vo), power supply pins (+5V and GND) and LED Backlight (Bklt+ and BKlt-) pins that you can use to power the LCD, control the display contrast, and turn on and off the LED backlight, respectively. The states of these pins (high or low) are the bits that you're writing to a register when you write, or the values you're reading when you read. An Enable pin that enables writing to the registers.A Read/Write (R/W) pin that selects reading mode or writing mode.You can select either the data register, which holds what goes on the screen, or an instruction register, which is where the LCD's controller looks for instructions on what to do next. A register select (RS) pin that controls where in the LCD's memory you're writing data to.The interface consists of the following pins: The LCDs have a parallel interface, meaning that the microcontroller has to manipulate several interface pins at once to control the display. There are many of them out there, and you can usually tell them by the 16-pin interface. The LiquidCrystal library allows you to control LCD displays that are compatible with the Hitachi HD44780 driver.
This article was revised on 8 by Karl Söderby.
0 kommentar(er)
