4 releases (2 breaking)

0.3.1 Oct 13, 2020
0.3.0 Sep 30, 2020
0.2.0 Sep 17, 2020
0.1.0 Aug 21, 2020

#132 in Embedded development

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Apache-2.0

53KB
1.5K SLoC

Drogue IoT ESP8266

crates.io docs.rs Matrix

A network driver for an ESP8266 attached via a USART.

Currently requires the ESP to be flashed with a 1.7.0.x version of the AT firmware provided by Espressif.

To use, you must configure your USART as 115,200 bps and 8-N-1, along with selecting the enable and reset connections to the board.

By using the initialize(...) function, you will get a 2-tuple back, container the Adapter and an Ingress object:

static mut RESPONSE_QUEUE: Queue<Response, U2> = Queue(i::Queue::new());
static mut NOTIFICATION_QUEUE: Queue<Response, U16> = Queue(i::Queue::new());

let (adapter, ingress) = esp8266::initialize(
    tx, rx,
    &mut en, &mut reset,
    unsafe { &mut RESPONSE_QUEUE },
    unsafe { &mut NOTIFICATION_QUEUE },
).unwrap();

In an RTIC app, this would occur during the init phase of the app, and both pieces would be placed into the shared resources.

The Ingress should be wired up to the USART interrupt in order to receive octets from the serial port:

#[task(binds = USART6, priority = 10, resources = [ingress])]
fn usart(ctx: usart::Context) {
    if let Err(b) = ctx.resources.ingress.isr() {
        info!("failed to ingress {}", b as char);
    }
}

Additionally, the Ingress should be attached to a timer loop in order to process all received octets in a timely fashion. The cycle speed is left as an exercise for the reader:

#[task(schedule = [digest], priority = 2, resources = [ingress])]
fn digest(mut ctx: digest::Context) {
    ctx.resources.ingress.lock(|ingress| ingress.digest());
    ctx.schedule.digest(ctx.scheduled + (DIGEST_DELAY * 100_000).cycles())
        .unwrap();
}

Once all iterrupts/tasks are enabled, the adapter may then be used in order to join a Wifi access point:

let result = adapter.join("myaccesspoint", "thepassword");

After successfully joining, the adapter may be convereted into a TCPNetworkStack:

 let network = adapter.into_network_stack();

 let socket = network.open(Mode::Blocking).unwrap();

 let socket_addr = SocketAddr::new(
     IpAddr::from_str("192.168.1.245").unwrap(),
     80,
 );

 let mut socket = network.connect(socket, socket_addr).unwrap();
 let result = network.write(&mut socket, b"GET / HTTP/1.1\r\nhost:192.168.1.245\r\n\r\n").unwrap();

 loop {
     let mut buffer = [0; 128];
     let result = network.read(&mut socket, &mut buffer);
     match result {
         Ok(len) => {
             if len > 0 {
                 let s = core::str::from_utf8(&buffer[0..len]);
                 match s {
                     Ok(s) => {
                         info!("recv: {} ", s);
                     }
                     Err(_) => {
                         info!("recv: {} bytes (not utf8)", len);
                     }
                 }
             }
         }
         Err(e) => {
             info!("ERR: {:?}", e);
             break;
         }
     }
 }

Dependencies

~1.5MB
~32K SLoC