impl Rust for ESP32

Code

The main changes in the code are the image data and width. This will display the resistor symbol in the IEC-60617 style.

Generate project using esp-generate

We will enable async (Embassy) support for this project. To create the project, use the esp-generate command. Run the following:

esp-generate --chip esp32 oled-rawimg

This will open a screen asking you to select options.

• Select the option "Enable unstable HAL features"
• Then, select the option "Adds embassy framework support".

Just save it by pressing "s" in the keyboard.

Update Cargo.toml

ssd1306 = { git = "https://github.com/rust-embedded-community/ssd1306.git", rev = "f3a2f7aca421fbf3ddda45ecef0dfd1f0f12330e", features = [
    "async",
] }
embedded-graphics = "0.8.1"

#![allow(unused)]
fn main() {
// 31x7 pixel
#[rustfmt::skip]
const IMG_DATA: &[u8] = &[
    // 1st row
    0b00000001,0b11111111,0b11111111,0b00000000,
    // 2nd row
    0b00000001,0b11111111,0b11111111,0b00000000,
    //3rd row
    0b00000001,0b10000000,0b00000011,0b00000000,
    //4th row
    0b11111111,0b10000000,0b00000011,0b11111110,
    //5th row
    0b00000001,0b10000000,0b00000011,0b00000000,
    //6th row
    0b00000001,0b11111111,0b11111111,0b00000000,
    //7th row
    0b00000001,0b11111111,0b11111111,0b00000000,
];
}

We need to set the width to 31. We'll draw the image at the point (x=35, y=35), though there's no particular reason for choosing these coordinates. I just wanted to show something other than the point zero. Feel free to experiment with different values for the point and explore other options.

#![allow(unused)]
fn main() {
 let raw_image = ImageRaw::<BinaryColor>::new(IMG_DATA, 31);

let image = Image::new(&raw_image, Point::new(35, 35));
}

Clone the existing project

You can also clone (or refer) project I created and navigate to the oled-rawimg folder.

git clone https://github.com/ImplFerris/esp32-projects
cd esp32-projects/oled-rawimg

The full code

#![no_std]
#![no_main]

use defmt::info;
use embassy_executor::Spawner;
use embassy_time::{Duration, Timer};
use embedded_graphics::image::{Image, ImageRaw};
use embedded_graphics::pixelcolor::BinaryColor;
use embedded_graphics::prelude::Point;
use embedded_graphics::prelude::*;
use esp_hal::timer::timg::TimerGroup;
use esp_hal::{clock::CpuClock, time::Rate};
use esp_println as _;
use ssd1306::mode::DisplayConfigAsync;
use ssd1306::{
    prelude::DisplayRotation, size::DisplaySize128x64, I2CDisplayInterface, Ssd1306Async,
};

#[panic_handler]
fn panic(_: &core::panic::PanicInfo) -> ! {
    loop {}
}

// 31x7 pixel
#[rustfmt::skip]
const IMG_DATA: &[u8] = &[
    // 1st row
    0b00000001,0b11111111,0b11111111,0b00000000,
    // 2nd row
    0b00000001,0b11111111,0b11111111,0b00000000,
    //3rd row
    0b00000001,0b10000000,0b00000011,0b00000000,
    //4th row
    0b11111111,0b10000000,0b00000011,0b11111110,
    //5th row
    0b00000001,0b10000000,0b00000011,0b00000000,
    //6th row
    0b00000001,0b11111111,0b11111111,0b00000000,
    //7th row
    0b00000001,0b11111111,0b11111111,0b00000000,
];

#[esp_hal_embassy::main]
async fn main(_spawner: Spawner) {
    // generator version: 0.3.1

    let config = esp_hal::Config::default().with_cpu_clock(CpuClock::max());
    let peripherals = esp_hal::init(config);

    let timer0 = TimerGroup::new(peripherals.TIMG1);
    esp_hal_embassy::init(timer0.timer0);

    info!("Embassy initialized!");

    let i2c_bus = esp_hal::i2c::master::I2c::new(
        peripherals.I2C0,
        esp_hal::i2c::master::Config::default().with_frequency(Rate::from_khz(400)),
    )
    .unwrap()
    .with_scl(peripherals.GPIO18)
    .with_sda(peripherals.GPIO23)
    .into_async();

    let interface = I2CDisplayInterface::new(i2c_bus);

    // initialize the display
    let mut display = Ssd1306Async::new(interface, DisplaySize128x64, DisplayRotation::Rotate0)
        .into_buffered_graphics_mode();
    display.init().await.unwrap();

    let raw_image = ImageRaw::<BinaryColor>::new(IMG_DATA, 31);
    let image = Image::new(&raw_image, Point::new(35, 35));

    image.draw(&mut display).unwrap();
    display.flush().await.unwrap();

    loop {
        Timer::after(Duration::from_secs(1)).await;
    }
}