Web Request

In the main function, we will call our function to initialize Wi-Fi. Once it is initialized, we will call send_http_request, which we will define shortly.

#![allow(unused)]
fn main() {
let wifi_stack = access_website::wifi::init_wifi(spawner, peripherals.WIFI).await;

info!("Wi-Fi Initialized");
Timer::after(Duration::from_millis(1000)).await;

send_http_request(wifi_stack).await;
}

Web Request and Response

We will work on the send_http_request function.

#![allow(unused)]
fn main() {
async fn send_http_request(wifi_stack: embassy_net::Stack<'static>) {
    // ...
}
}

First, we create the TCP and DNS clients, which we then use to create the HTTP client.

#![allow(unused)]
fn main() {
let tcp_client = TcpClient::new(
    wifi_stack,
    mk_static!(
        TcpClientState
        <1, 1500, 1500>,
        TcpClientState::<1, 1500, 1500>::new()
    ),
);
let dns_client = DnsSocket::new(wifi_stack);

let mut client = HttpClient::new(&tcp_client, &dns_client);
}

We will send the web request to the httpbin.org website. To receive the response, we create a buffer. We then send the request using the buffer to store the response.

#![allow(unused)]
fn main() {
let mut rx_buf = [0u8; 4096];

let mut builder = client
    .request(Method::GET, "http://httpbin.org/get?hello=Hello+esp-hal")
    .await
    .inspect_err(|e| error!("Request Build Error: {:?}", e))
    .unwrap();

// let mut builder = builder.headers(&[("Host", "httpbin.org"), ("Connection", "close")]);

info!("Sending HTTP Request");
let response = builder.send(&mut rx_buf).await.unwrap();
}

We then read the response body and print it.

#![allow(unused)]
fn main() {
match response.body().read_to_end().await {
    Ok(data) => {
        if let Ok(st) = core::str::from_utf8(data) {
            info!("Body: {}", st);
        }
    }
    Err(e) => info!("Body error: {:?}", e),
}
}

We can further process the response body as JSON using crates like serde, but we will stop here and cover this in later chapters.

Run the Program

Unlike the previous examples, we need to pass the Wi-Fi credentials as environment variables. You can either set them in your shell beforehand or prefix the command with the variables like this:

SSID='YOUR_WIFI_NAME' PASSWORD='YOUR_WIFI_PASSWORD' cargo run --release

Clone the existing project

You can clone the project I created or refer to the existing project and navigate to the access-website folder.

git clone https://github.com/ImplFerris/esp32c5-projects
cd esp32c5-projects/access-website/