esp-hal/examples/src/bin/wifi_embassy_dhcp.rs

//! Embassy DHCP Example
//!
//!
//! Set SSID and PASSWORD env variable before running this example.
//!
//! This gets an ip address via DHCP then performs an HTTP get request to some "random" server
//!
//! Because of the huge task-arena size configured this won't work on ESP32-S2
//! When using USB-SERIAL-JTAG you have to activate the feature `phy-enable-usb` in the esp-wifi crate.

//% FEATURES: embassy embassy-generic-timers esp-wifi esp-wifi/async esp-wifi/embassy-net esp-wifi/wifi-default esp-wifi/wifi esp-wifi/utils
//% CHIPS: esp32 esp32s2 esp32s3 esp32c2 esp32c3 esp32c6

#![no_std]
#![no_main]

use embassy_executor::Spawner;
use embassy_net::{tcp::TcpSocket, Ipv4Address, Stack, StackResources};
use embassy_time::{Duration, Timer};
use esp_alloc as _;
use esp_backtrace as _;
use esp_hal::{prelude::*, rng::Rng, timer::timg::TimerGroup};
use esp_println::println;
use esp_wifi::{
    init,
    wifi::{
        ClientConfiguration,
        Configuration,
        WifiController,
        WifiDevice,
        WifiEvent,
        WifiStaDevice,
        WifiState,
    },
    EspWifiController,
};

// When you are okay with using a nightly compiler it's better to use https://docs.rs/static_cell/2.1.0/static_cell/macro.make_static.html
macro_rules! mk_static {
    ($t:ty,$val:expr) => {{
        static STATIC_CELL: static_cell::StaticCell<$t> = static_cell::StaticCell::new();
        #[deny(unused_attributes)]
        let x = STATIC_CELL.uninit().write(($val));
        x
    }};
}

const SSID: &str = env!("SSID");
const PASSWORD: &str = env!("PASSWORD");

#[esp_hal_embassy::main]
async fn main(spawner: Spawner) -> ! {
    esp_println::logger::init_logger_from_env();
    let peripherals = esp_hal::init({
        let mut config = esp_hal::Config::default();
        config.cpu_clock = CpuClock::max();
        config
    });

    esp_alloc::heap_allocator!(72 * 1024);

    let timg0 = TimerGroup::new(peripherals.TIMG0);

    let init = &*mk_static!(
        EspWifiController<'static>,
        init(
            timg0.timer0,
            Rng::new(peripherals.RNG),
            peripherals.RADIO_CLK,
        )
        .unwrap()
    );

    let wifi = peripherals.WIFI;
    let (wifi_interface, controller) =
        esp_wifi::wifi::new_with_mode(&init, wifi, WifiStaDevice).unwrap();

    cfg_if::cfg_if! {
        if #[cfg(feature = "esp32")] {
            let timg1 = TimerGroup::new(peripherals.TIMG1);
            esp_hal_embassy::init(timg1.timer0);
        } else {
            use esp_hal::timer::systimer::{SystemTimer, Target};
            let systimer = SystemTimer::new(peripherals.SYSTIMER).split::<Target>();
            esp_hal_embassy::init(systimer.alarm0);
        }
    }

    let config = embassy_net::Config::dhcpv4(Default::default());

    let seed = 1234; // very random, very secure seed

    // Init network stack
    let stack = &*mk_static!(
        Stack<WifiDevice<'_, WifiStaDevice>>,
        Stack::new(
            wifi_interface,
            config,
            mk_static!(StackResources<3>, StackResources::<3>::new()),
            seed
        )
    );

    spawner.spawn(connection(controller)).ok();
    spawner.spawn(net_task(&stack)).ok();

    let mut rx_buffer = [0; 4096];
    let mut tx_buffer = [0; 4096];

    loop {
        if stack.is_link_up() {
            break;
        }
        Timer::after(Duration::from_millis(500)).await;
    }

    println!("Waiting to get IP address...");
    loop {
        if let Some(config) = stack.config_v4() {
            println!("Got IP: {}", config.address);
            break;
        }
        Timer::after(Duration::from_millis(500)).await;
    }

    loop {
        Timer::after(Duration::from_millis(1_000)).await;

        let mut socket = TcpSocket::new(&stack, &mut rx_buffer, &mut tx_buffer);

        socket.set_timeout(Some(embassy_time::Duration::from_secs(10)));

        let remote_endpoint = (Ipv4Address::new(142, 250, 185, 115), 80);
        println!("connecting...");
        let r = socket.connect(remote_endpoint).await;
        if let Err(e) = r {
            println!("connect error: {:?}", e);
            continue;
        }
        println!("connected!");
        let mut buf = [0; 1024];
        loop {
            use embedded_io_async::Write;
            let r = socket
                .write_all(b"GET / HTTP/1.0\r\nHost: www.mobile-j.de\r\n\r\n")
                .await;
            if let Err(e) = r {
                println!("write error: {:?}", e);
                break;
            }
            let n = match socket.read(&mut buf).await {
                Ok(0) => {
                    println!("read EOF");
                    break;
                }
                Ok(n) => n,
                Err(e) => {
                    println!("read error: {:?}", e);
                    break;
                }
            };
            println!("{}", core::str::from_utf8(&buf[..n]).unwrap());
        }
        Timer::after(Duration::from_millis(3000)).await;
    }
}

#[embassy_executor::task]
async fn connection(mut controller: WifiController<'static>) {
    println!("start connection task");
    println!("Device capabilities: {:?}", controller.get_capabilities());
    loop {
        match esp_wifi::wifi::get_wifi_state() {
            WifiState::StaConnected => {
                // wait until we're no longer connected
                controller.wait_for_event(WifiEvent::StaDisconnected).await;
                Timer::after(Duration::from_millis(5000)).await
            }
            _ => {}
        }
        if !matches!(controller.is_started(), Ok(true)) {
            let client_config = Configuration::Client(ClientConfiguration {
                ssid: SSID.try_into().unwrap(),
                password: PASSWORD.try_into().unwrap(),
                ..Default::default()
            });
            controller.set_configuration(&client_config).unwrap();
            println!("Starting wifi");
            controller.start().await.unwrap();
            println!("Wifi started!");
        }
        println!("About to connect...");

        match controller.connect().await {
            Ok(_) => println!("Wifi connected!"),
            Err(e) => {
                println!("Failed to connect to wifi: {e:?}");
                Timer::after(Duration::from_millis(5000)).await
            }
        }
    }
}

#[embassy_executor::task]
async fn net_task(stack: &'static Stack<WifiDevice<'static, WifiStaDevice>>) {
    stack.run().await
}