klips/esp/rust/02_esp-gen-no-std/src/bin/main.rs

#![no_std]
#![no_main]
#![deny(
    clippy::mem_forget,
    reason = "mem::forget is generally not safe to do with esp_hal types, especially those \
    holding buffers for the duration of a data transfer."
)]

use esp_hal::i2c::master::BusTimeout;
use esp_hal::{
    clock::CpuClock,
    gpio::{Level, Output, OutputConfig},
    main,
    time::{Duration, Instant},
};
use fugit::RateExtU32;

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

// This creates a default app-descriptor required by the esp-idf bootloader.
// For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
esp_bootloader_esp_idf::esp_app_desc!();

#[main]
fn main() -> ! {
    // generator version: 0.5.0
    esp_println::logger::init_logger_from_env();
    let config = esp_hal::Config::default().with_cpu_clock(CpuClock::max());
    let peripherals = esp_hal::init(config);
    let i2c_config = esp_hal::i2c::master::Config::default().with_timeout(BusTimeout::Maximum);
    let mut i2c = esp_hal::i2c::master::I2c::new(peripherals.I2C0, i2c_config)
        .unwrap()
        .with_sda(peripherals.GPIO21)
        .with_scl(peripherals.GPIO22);

    let mut led = Output::new(peripherals.GPIO2, Level::High, OutputConfig::default());
    loop {
        log::info!("Scanning for I2C devices..");
        for i in 0..=127u8 {
            let res = i2c.read(i, &mut [0]);
            match res {
                Ok(_) => {
                    log::info!("Device found at address: {}", i);
                }
                Err(err) => {
                    log::warn!("Failed to read device address: {:?}", err);
                }
            }
        }
        led.toggle();
        let delay_start = Instant::now();
        while delay_start.elapsed() < Duration::from_millis(500) {}
    }

    // for inspiration have a look at the examples at https://github.com/esp-rs/esp-hal/tree/esp-hal-v1.0.0-rc.0/examples/src/bin
}