【rust/树莓派】使用rppal&embedded-graphics控制st7789 LCD屏幕

说在前面

• 树莓派版本：4b
• LCD模块：ST7789V2 240*280 LCD
• 树莓派系统：Linux raspberrypi 5.15.76-v8+ #1597 SMP aarch64 GNU/Linux
• rust版本：rustc 1.73.0

模块详情

• 某雪的1.69inch LCD模块，包含杜邦线
  

准备工作

• 树莓派相关见上篇文章
• 安装rust
  这里直接在树莓派系统上安装的rust，未使用交叉编译等手段。

开始

• 相关依赖包

  [dependencies]
  rppal = { version = "0.15.0", features = ["hal"] }
  embedded-graphics = { version = "0.8.1", features = ["defmt"]}
  display-interface-spi = "0.4.1"
  mipidsi = "0.7.1"
  

• 代码

  use display_interface_spi::SPIInterfaceNoCS;
  use embedded_graphics::mono_font::ascii::FONT_10X20;
  use embedded_graphics::mono_font::MonoTextStyle;
  use embedded_graphics::pixelcolor::Rgb565;
  use embedded_graphics::prelude::{Point, RgbColor, DrawTarget};
  use embedded_graphics::text::Text;
  use embedded_graphics::Drawable;
  use mipidsi::Builder;
  use rppal::gpio::Gpio;
  use rppal::spi::Spi;
  use std::process::ExitCode;
  
  fn main() -> ExitCode {
      // GPIO
      let gpio = Gpio::new().unwrap();
      // reset
      let rst = gpio.get(27).unwrap().into_output();
      // backlight
      let mut backlight = gpio.get(18).unwrap().into_output();
      // data/commend
      let dc = gpio.get(25).unwrap().into_output();
  	// spi
      let spi = Spi::new(
          rppal::spi::Bus::Spi0,
          rppal::spi::SlaveSelect::Ss0,
          60_000_000,
          rppal::spi::Mode::Mode0,
      )
      .unwrap();
      let di = SPIInterfaceNoCS::new(spi, dc);
  
      let mut delay = rppal::hal::Delay::new();
      let mut display = Builder::st7789(di)
          .with_display_size(240, 280)
          .with_orientation(mipidsi::Orientation::Landscape(true))
          .with_invert_colors(mipidsi::ColorInversion::Inverted)
          .init(&mut delay, Some(rst))
          .unwrap();
  
      // Text
      let char_w = 10;
      let text = "Hello World ^_^;";
      let mut text_x = 120;
      let text_y = 280 / 2;
      let text_style = MonoTextStyle::new(&FONT_10X20, Rgb565::WHITE);
  
      // Alternating color
      let colors = [Rgb565::RED, Rgb565::GREEN, Rgb565::BLUE];
  
      // Clear the display initially
      display.clear(colors[0]).unwrap();
  
      // Turn on backlight
      backlight.set_high();
  
      let mut last = std::time::Instant::now();
      let mut counter = 0;
      loop {
          let elapsed = last.elapsed().as_secs_f64();
          if elapsed < 0.00125 {
              continue;
          }
          last = std::time::Instant::now();
          counter += 1;
  
          // Fill the display with alternating colors every 8 frames
          display.clear(colors[(counter / 8) % colors.len()]).unwrap();
  
          // Draw text
          let right = Text::new(text, Point::new(text_x, text_y), text_style)
              .draw(&mut display)
              .unwrap();
          text_x = if right.x <= 0 { 240 } else { text_x - char_w };
      }
  
      // Turn off backlight and clear the display
      backlight.set_low();
      display.clear(Rgb565::BLACK).unwrap();
  
      ExitCode::SUCCESS
  }
  

运行

cargo run

结果