patryk27 / pwr-hd44780

A driver for HD44780 LCDs, with support for GPIO and I2C - created for use with Raspberry Pi

pwr-hd44780

Documentation

A Rust crate allowing to communicate with the HD44780 LCDs.

What buses are supported?

• 4-bit GPIO bus (thanks to the rppal library),
• I2C bus (thanks to the rust-i2cdev library).

Would you mind showing me some code?

Sure, pal:

extern crate pwr_hd44780;

use pwr_hd44780::Hd44780;

fn main() {
    run().unwrap();
}

fn run() -> Result<(), Box<std::error::Error>> {
    // create the LCD's bus instance;
    // use device at address 0x27 on the first I2C bus
    let lcd_bus = pwr_hd44780::I2CBus::new(
        "/dev/i2c-1", 0x27,
    )?;

    // create the direct LCD's instance;
    // use bus created before and assume LCD's width x height = 20 x 4
    let mut lcd = pwr_hd44780::DirectLcd::new(
        Box::new(lcd_bus),
        20, 4,
    )?;

    // finally - print our text
    lcd.clear()?;
    lcd.print("Hello World! :-)")?;

    Ok(())
}

For more examples, take a dive into the examples directory.

License

Copyright (c) 2018, Patryk Wychowaniec <[email protected]>.
Licensed under the MIT license.

pwr-hd44780's Issues

20x4 lcd oveflow

The overflow seems to be working wrongly for 20x4 LCDs. I have the following code:

let mut lcd = pwr_hd44780::DirectLcd::new(Box::new(lcd_bus), 20, 4)
    .expect("Error creating lcd instance");

But, when I print for example abcdefghijklmnopqrstuvxyz abcdefghijklmnopqrstuvxyz abcdefghijklmnopqrstuvxyz, it appears on my lcd as:

abcdefghijklmnopqrst
opqrstuvxyz abcdefgh
uvxyz abcdefghijklmn
ijklmnopqrstuvxyz

It is overflowing in the order of first line -> third line -> second line -> fourth line, instead of first line -> second line -> third line -> fourth line. What do I do?