display-hat-mini-driver

This is a very simple basic implementation of a driver for the Pimoroni Display HAT Mini (pinout).

Implemented features:

Bitmap drawing
Tear effect pin
Button states
RGB Led

You can also use this driver from node.js, using this library: display-hat-mini-node.

Quick example

use display_hat_mini_driver::DisplayHATMini;
use std::error::Error;

fn main() -> Result<(), Box<dyn Error>> {
    let mut dhm = DisplayHATMini::new()?;
    let width = dhm.width;
    let height = dhm.height;
    let bpp = 3;

    dhm.init()?;

    let mut buffer: Vec<u8> = vec![0; (width * height * bpp) as usize];

    for y in 0..height {
        for x in 0..width {
            let offset= ((y * width + x) * bpp) as usize;
            buffer[offset] = y as u8; //red
            buffer[offset + 1] = x as u8; //green
            buffer[offset + 2] = 0; //blue;
        }
    }

    dhm.display_rgb(&buffer[..])?;
    Ok(())
}

Features

Bitmap drawing

display_rgb(&mut self, rgb_buffer: &[u8]) -> Result<(), Box<dyn Error>>

This function draws the entire bitmap to the display, the buffer is expected to have a 320x240 pixels bitmap where each pixel has the format RGB24.

Tear effect pin

set_vsync(&mut self, use_it: bool)

Call this with true if you want to wait for the tear effect pin to go high before drawing the bitmap to the display. It does not eliminate all tearing though.

Button states

read_buttons(&mut self) -> Result<u8, Box<dyn Error>>

This function returns a byte with flags for pressed buttons. The lower nibble indicates the estate for the four buttons of the display.

bits	7	6	5	4	3	2	1	0
buttons	-	-	-	-	Y	X	B	A

For example, the byte 0x08 means that button Y is currently pressed.

RGB LED

set_led(&mut self, red: u8, green: u8, blue: u8) -> Result<(), Box<dyn Error>>

Simply call this function to show the RGB in the integrated RGB LED.

niofis / display-hat-mini-driver