rylr998-embassy

no_std driver for the REYAX RYLR998 LoRa radio module, built on Embassy and the embedded-io-async traits.

Hand in any UART that implements embedded_io_async::Read + Write and you get a Radio<UART> with the same surface as the host crates — but it runs on a Cortex-M target with no allocator.

Validated on Raspberry Pi Pico 2 (RP2350) + a real RYLR998 module. The provided examples/pico_smoke.rs flashes via probe-rs, brings up the radio over UART1, and reports activity over either RTT or a UART console forwarded through picoprobe.

Example

use embassy_rp::{bind_interrupts, peripherals, uart};
use rylr998_core::Event;

bind_interrupts!(struct Irqs {
    UART1_IRQ => uart::BufferedInterruptHandler<peripherals::UART1>;
});

#[embassy_executor::main]
async fn main(_spawner: embassy_executor::Spawner) {
    let p = embassy_rp::init(Default::default());

    let tx_buf: &'static mut [u8; 256] = cortex_m::singleton!(: [u8; 256] = [0; 256]).unwrap();
    let rx_buf: &'static mut [u8; 256] = cortex_m::singleton!(: [u8; 256] = [0; 256]).unwrap();

    let uart = uart::BufferedUart::new(
        p.UART1, p.PIN_8, p.PIN_9, Irqs, tx_buf, rx_buf, uart::Config::default(),
    );
    let mut radio = rylr998_embassy::Radio::new(uart);

    radio.set_address(5).await.unwrap();

    loop {
        let _ = radio.next_event(embassy_time::Duration::from_secs(60), |e: Event<'_>| {
            // log e via defmt or your channel of choice
            None::<()>
        }).await;
    }
}

API surface

• Radio::new(uart) — wrap any embedded_io_async::Read + Write UART.
• AT commands: ping, set_address / address, set_network_id / network_id, set_band / band, set_parameters / parameters, crfop, factory_reset, send.
• next_event<F, R>(timeout, handler) — runs a callback for each unsolicited event arriving on the wire; returns when the callback yields Some(_) or the timeout fires.

uid / version are omitted in this crate; their &str payload would require an alloc-backed String to return owned. If you need them, drop to rylr998-core directly.

Memory layout (RP2350)

The example uses a hand-written memory.x modeled on rp-hal's RP2350 layout: vector table first, then a .start_block with the boot ROM's IMAGE_DEF (configured as a secure EXE), then .text, then a .end_block at the end.

Related crates

• rylr998-core — pure protocol logic.
• rylr998-std — blocking host driver.
• rylr998-tokio — async host driver.

License

Dual-licensed: MIT or Apache-2.0, at your option.