Create task for outputting to SSD1351 display

Cargo.lock

@@ -83,6 +83,12 @@ version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8f68f53c83ab957f72c32642f3868eec03eb974d1fb82e453128456482613d36"
 
+[[package]]
+name = "byte-slice-cast"
+version = "1.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3ac9f8b63eca6fd385229b3675f6cc0dc5c8a5c8a54a59d4f52ffd670d87b0c"
+
 [[package]]
 name = "bytemuck"
 version = "1.21.0"
@@ -232,6 +238,24 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "display-interface"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ba2aab1ef3793e6f7804162debb5ac5edb93b3d650fbcc5aeb72fcd0e6c03a0"
+
+[[package]]
+name = "display-interface-spi"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f86b9ec30048b1955da2038fcc3c017f419ab21bb0001879d16c0a3749dc6b7a"
+dependencies = [
+ "byte-slice-cast",
+ "display-interface",
+ "embedded-hal 1.0.0",
+ "embedded-hal-async",
+]
+
 [[package]]
 name = "document-features"
 version = "0.2.11"
@@ -400,6 +424,29 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4fc247028eae04174b6635104a35b1ed336aabef4654f5e87a8f32327d231970"
 
+[[package]]
+name = "embedded-graphics"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0649998afacf6d575d126d83e68b78c0ab0e00ca2ac7e9b3db11b4cbe8274ef0"
+dependencies = [
+ "az",
+ "byteorder",
+ "embedded-graphics-core",
+ "float-cmp",
+ "micromath",
+]
+
+[[package]]
+name = "embedded-graphics-core"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba9ecd261f991856250d2207f6d8376946cd9f412a2165d3b75bc87a0bc7a044"
+dependencies = [
+ "az",
+ "byteorder",
+]
+
 [[package]]
 name = "embedded-hal"
 version = "0.2.7"
@@ -498,6 +545,15 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
+[[package]]
+name = "float-cmp"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "98de4bbd547a563b716d8dfa9aad1cb19bfab00f4fa09a6a4ed21dbcf44ce9c4"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -697,6 +753,12 @@ version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[package]]
+name = "micromath"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3c8dda44ff03a2f238717214da50f65d5a53b45cd213a7370424ffdb6fae815"
+
 [[package]]
 name = "nb"
 version = "0.1.3"
@@ -800,13 +862,16 @@ name = "pico-enviro-sensor"
 version = "0.1.0"
 dependencies = [
  "cortex-m-rt",
+ "display-interface-spi",
  "embassy-embedded-hal",
  "embassy-executor",
  "embassy-rp",
  "embassy-sync",
  "embassy-time",
+ "embedded-graphics",
  "rtt-target",
  "scd4x",
+ "ssd1351",
  "static_cell",
 ]
 
@@ -1113,6 +1178,18 @@ dependencies = [
  "rgb",
 ]
 
+[[package]]
+name = "ssd1351"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21c426aced0940ed7c25b8134d6a0bf9745ade9f788ca54bec14c99e67120d6a"
+dependencies = [
+ "display-interface",
+ "display-interface-spi",
+ "embedded-graphics-core",
+ "embedded-hal 1.0.0",
+]
+
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.0"

Cargo.toml

@@ -25,6 +25,7 @@ embassy-time = "0.4.0"
 embassy-sync = "0.6.2"
 embassy-embedded-hal = "0.3.0"
 static_cell = "2.1.0"
+embedded-graphics = "0.8.1"
 
 # System
 cortex-m-rt = "0.7.5"
@@ -34,6 +35,8 @@ rtt-target = "0.6.1"
 scd4x = { git = "https://github.com/twokilohertz/scd4x-rs.git", branch = "conversion-fixes", features = [
     "scd41",
 ] }
+ssd1351 = "0.5.0"
+display-interface-spi = "0.5.0"
 
 [profile.dev]
 opt-level = "s"

src/display_task.rs

@@ -0,0 +1,51 @@
+// System
+use embassy_embedded_hal::shared_bus::blocking::spi::SpiDeviceWithConfig;
+use embassy_rp::{gpio::Output, spi::Config};
+use rtt_target::rprintln;
+
+// Display
+use display_interface_spi::SPIInterface;
+use ssd1351::{
+    builder::Builder,
+    mode::GraphicsMode,
+    properties::{DisplayRotation, DisplaySize},
+};
+
+// Graphics
+use embedded_graphics::{
+    pixelcolor::Rgb565,
+    prelude::{Point, Primitive, WebColors},
+    primitives::{Circle, PrimitiveStyle},
+    Drawable,
+};
+
+use crate::Spi0BusMutex;
+
+/// Output to the SSD1351 display
+#[embassy_executor::task]
+pub async fn display_output_task(
+    spi_bus: &'static Spi0BusMutex,
+    cs: Output<'static>,
+    dc: Output<'static>,
+    rst: &'static mut Output<'static>,
+    spi_config: Config,
+) {
+    rprintln!("Display output task started");
+
+    let spi_dev = SpiDeviceWithConfig::new(spi_bus, cs, spi_config);
+    let interface = SPIInterface::new(spi_dev, dc);
+
+    let mut display: GraphicsMode<_> = Builder::new()
+        .with_size(DisplaySize::Display128x128)
+        .with_rotation(DisplayRotation::Rotate0)
+        .connect_interface(interface)
+        .into();
+
+    display.reset(rst, &mut embassy_time::Delay).unwrap();
+    display.init().unwrap();
+
+    Circle::new(Point::new(0, 0), 128)
+        .into_styled(PrimitiveStyle::with_fill(Rgb565::CSS_CHARTREUSE))
+        .draw(&mut display)
+        .unwrap();
+}

src/main.rs

@@ -1,6 +1,7 @@
 #![no_std]
 #![no_main]
 
+mod display_task;
 mod sensor_task;
 
 use core::cell::RefCell;
@@ -8,18 +9,26 @@ use core::cell::RefCell;
 use rtt_target::{rprintln, rtt_init_print};
 
 use embassy_executor::Spawner;
-use embassy_rp::{block::ImageDef, i2c::Blocking, i2c::I2c, peripherals::I2C0};
+use embassy_rp::{
+    block::ImageDef,
+    gpio::{Level, Output},
+    i2c,
+    peripherals::{I2C0, SPI0},
+    spi,
+};
 use embassy_sync::blocking_mutex::{raw::NoopRawMutex, Mutex};
 use embassy_time::Timer;
 use static_cell::StaticCell;
 
+use display_task::display_output_task;
 use sensor_task::sensor_read_task;
 
 embassy_rp::bind_interrupts!(struct Irqs {
     I2C0_IRQ => embassy_rp::i2c::InterruptHandler<embassy_rp::peripherals::I2C0>;
 });
 
-type I2c0BusType = Mutex<NoopRawMutex, RefCell<I2c<'static, I2C0, Blocking>>>;
+type I2c0BusMutex = Mutex<NoopRawMutex, RefCell<i2c::I2c<'static, I2C0, i2c::Blocking>>>;
+type Spi0BusMutex = Mutex<NoopRawMutex, RefCell<spi::Spi<'static, SPI0, spi::Blocking>>>;
 
 /// Entrypoint
 #[embassy_executor::main]
@@ -31,17 +40,41 @@ async fn main(spawner: Spawner) {
 
     let peripherals = embassy_rp::init(Default::default());
 
-    // Initialise I2C0 on pins 4 & 5 for the SCD41 sensor
+    // Initialise I2C0 (SDA: pin 4, SCL: pin 5)
     let sda = peripherals.PIN_4;
     let scl = peripherals.PIN_5;
     let mut i2c_config = embassy_rp::i2c::Config::default();
     i2c_config.frequency = 400_000u32; // 400 kHz
     let i2c_bus = embassy_rp::i2c::I2c::new_blocking(peripherals.I2C0, scl, sda, i2c_config);
-    static I2C0_BUS: StaticCell<I2c0BusType> = StaticCell::new();
+    static I2C0_BUS: StaticCell<I2c0BusMutex> = StaticCell::new();
     let shared_i2c0_bus = I2C0_BUS.init(Mutex::new(RefCell::new(i2c_bus)));
 
+    // Start new task for reading data from the sensor
     spawner.must_spawn(sensor_read_task(shared_i2c0_bus));
 
+    // Initialise SPI0 (MOSI: pin 19, SCLK: pin 18, CS: pin 17, DC: pin 14, RST: pin 15)
+    let mosi = peripherals.PIN_19;
+    let sclk = peripherals.PIN_18;
+    let cs = Output::new(peripherals.PIN_17, Level::Low);
+    let dc = Output::new(peripherals.PIN_14, Level::Low);
+    static SPI0_RST_PIN: StaticCell<Output<'_>> = StaticCell::new(); // Initialised before launching task
+    let rst = SPI0_RST_PIN.init(Output::new(peripherals.PIN_15, Level::Low));
+
+    let mut spi_config = spi::Config::default();
+    spi_config.frequency = 4_000_000u32; // 4 MHz
+    let spi_bus = spi::Spi::new_blocking_txonly(peripherals.SPI0, sclk, mosi, spi_config.clone());
+    static SPI0_BUS: StaticCell<Spi0BusMutex> = StaticCell::new();
+    let shared_spi0_bus = SPI0_BUS.init(Mutex::new(RefCell::new(spi_bus)));
+
+    // Start new task for outputting to the display
+    spawner.must_spawn(display_output_task(
+        shared_spi0_bus,
+        cs,
+        dc,
+        rst,
+        spi_config.clone(),
+    ));
+
     loop {
         Timer::after_secs(1).await;
     }

src/sensor_task.rs

@@ -6,10 +6,11 @@ use rtt_target::rprintln;
 // Sensor
 use scd4x::Scd4x;
 
-use crate::I2c0BusType;
+use crate::I2c0BusMutex;
 
+/// Read CO2/temp./humidity data from the sensor
 #[embassy_executor::task]
-pub async fn sensor_read_task(i2c_bus: &'static I2c0BusType) {
+pub async fn sensor_read_task(i2c_bus: &'static I2c0BusMutex) {
     rprintln!("Sensor read task started");
 
     Timer::after_millis(30).await; // SCD41 power-up delay
@@ -30,7 +31,7 @@ pub async fn sensor_read_task(i2c_bus: &'static I2c0BusType) {
     scd41.start_periodic_measurement().unwrap();
 
     loop {
-        Timer::after_secs(5).await; // start_periodic_measurement() returns new sensor data every 5 seconds
+        Timer::after_secs(5).await; // start_periodic_measurement returns new sensor data every 5 seconds
 
         match scd41.measurement() {
             Ok(data) => {