Trouble with inverted uart on esp32s3

[tommasoclini]

Hello guys, I'm having trouble getting inverted logic levels uart to work on esp32s3, this is the code I'm running (simplified):

#[main]
async fn main(spawner: Spawner) {
// ...
    let in_signal = InputSignal::from(peripherals.GPIO15).inverted();
    in_signal.pull_direction(gpio::Pull::Down);
    let out_signal = OutputSignal::from(peripherals.GPIO16).inverted();
    out_signal.set_to_push_pull_output();

    let (uartrx, uarttx) =
        esp_hal::uart::Uart::new(peripherals.UART1, esp_hal::uart::Config::default())
            .unwrap()
            .with_rx(in_signal)
            .with_tx(out_signal)
            .into_async()
            .split();

    spawner.spawn(writer_task(uarttx)).unwrap();
    spawner.spawn(reader_task(uartrx)).unwrap();
// ...
}

#[task]
async fn writer_task(mut tx: esp_hal::uart::UartTx<'static, Async>) {
    loop {
        _ = embedded_io_async::Write::write_all(&mut tx, b"ciao")
            .await
            .inspect(|_| debug!("managed to send data to uart"))
            .inspect_err(|e| warn!("failed to send data to uart, e: {e}"));
        Timer::after(Duration::from_millis(500)).await;
    }
}

#[task]
async fn reader_task(mut rx: esp_hal::uart::UartRx<'static, Async>) {
    loop {
        let mut buf = [0; 32];
        _ = embedded_io_async::Read::read(&mut rx, &mut buf)
            .await
            .inspect(|s| info!("received data: {:?}", core::str::from_utf8(&buf[..*s])))
            .inspect_err(|e| warn!("failed to receive data, e: {e}"));
    }
}

I have physically wired gpio 15 and 16 together, when using not inverted RX, I receive the data no matter if the TX is inverted or not, but if I invert the RX, I do not receive the data with inverted nor not inverted TX.

This is what I get repeatedly when I use inverted RX (with either TX inverted or not inverted):

WARN - failed to receive data, e: A framing error was detected on the RX line
INFO - received data: Ok("NKO")

What am I doing wrong here?

[tommasoclini]

This has been fixed in the main branch, I'll close this discussion