examples: st7789: Initial commit

This is a basic example of displaying data on a st7789 screen using
Tock.

Signed-off-by: Alistair Francis <[email protected]>

Cargo.toml

@@ -48,9 +48,18 @@ libtock_temperature = { path = "apis/sensors/temperature" }
 
 embedded-hal = { version = "1.0", optional = true }
 
+[dev-dependencies]
+mipidsi = "0.8.0"
+display-interface-spi = "0.5"
+embedded-graphics = "0.8"
+
 [build-dependencies]
 libtock_build_scripts = { path = "build_scripts" }
 
+[[example]]
+name = "st7789"
+required-features = ["rust_embedded"]
+
 [profile.dev]
 debug = true
 lto = true

examples/st7789.rs

@@ -0,0 +1,75 @@
+//! This sample demonstrates displaying text on a ST7789 display
+//! using a rust-embedded based crate
+
+#![no_main]
+#![no_std]
+use core::fmt::Write;
+use libtock::alarm::{Alarm, Milliseconds};
+use libtock::console::Console;
+use libtock::gpio::Gpio;
+use libtock::runtime::{set_main, stack_size};
+use libtock::spi_controller::EmbeddedHalSpi;
+
+use display_interface_spi::SPIInterface;
+use embedded_graphics::{
+    mono_font::{ascii::FONT_10X20, MonoTextStyle},
+    pixelcolor::Rgb565,
+    prelude::*,
+    text::Text,
+};
+use mipidsi::{models::ST7789, options::ColorInversion, Builder};
+
+set_main! {main}
+stack_size! {0x1000}
+
+// Display
+const W: i32 = 240;
+const H: i32 = 240;
+
+struct Delay;
+
+impl embedded_hal::delay::DelayNs for Delay {
+    fn delay_ns(&mut self, ns: u32) {
+        Alarm::sleep_for(Milliseconds(ns / (1000 * 1000))).unwrap();
+    }
+}
+
+fn main() {
+    writeln!(Console::writer(), "st7789: example\r").unwrap();
+
+    let mut gpio_dc = Gpio::get_pin(0).unwrap();
+    let dc = gpio_dc.make_output().unwrap();
+
+    let mut gpio_reset = Gpio::get_pin(1).unwrap();
+    let reset = gpio_reset.make_output().unwrap();
+
+    let di = SPIInterface::new(EmbeddedHalSpi, dc);
+
+    let mut delay = Delay;
+    let mut display = Builder::new(ST7789, di)
+        .display_size(W as u16, H as u16)
+        .invert_colors(ColorInversion::Inverted)
+        .reset_pin(reset)
+        .init(&mut delay)
+        .unwrap();
+
+    // Text
+    let text_style = MonoTextStyle::new(&FONT_10X20, Rgb565::WHITE);
+    let text = "Hello World ^_^;";
+    let text_x = W;
+    let text_y = H / 2;
+
+    // Clear the display initially
+    display.clear(Rgb565::BLUE).unwrap();
+
+    writeln!(Console::writer(), "Clear complete\r").unwrap();
+
+    // Draw text
+    Text::new(text, Point::new(text_x, text_y), text_style)
+        .draw(&mut display)
+        .unwrap();
+
+    loop {
+        TockSyscalls::yield_wait();
+    }
+}