Written by Natesh Narain
on 

Icarus Rev E - Firmware Bringup

Quick update on the new icarus controller.

Having issues with the USB connection to the board. What’s odd is I’m having the same issue with USB to the Rev D version (ESP32-C3 module) and my STM32F4 devboard.

So instead of using the bootloader DFU I’m falling back to flashing over UART. Luckily this worked without issue but I’ve lost a convenient “run” option for uploading firmware (now I have to explicitly flashing the board using the STM32 Cube Programmer).

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Probably going to make another attempt to do the firmware in Rust using Embassy but I love the idea of async-io on embedded. But I’ll go back to C++ if things get iffy.

Embassy firmware for simple UART hello world.

#![no_std]
#![no_main]

use cortex_m_rt::entry;
use defmt::*;
use embassy_stm32::usart::{Config, Uart};
use embassy_stm32::{bind_interrupts, peripherals, usart};
use {defmt_rtt as _, panic_probe as _};

#[entry]
fn main() -> ! {
    info!("Hello World!");

    let p = embassy_stm32::init(Default::default());

    let config = Config::default();
    let mut usart = Uart::new_blocking(p.USART1, p.PA10, p.PA9, config).unwrap();

    loop {
        unwrap!(usart.blocking_write(b"Hello Embassy World!\r\n"));
    }
}

image not found!

This was just to ensure the board was programmable and working.

Next Steps

Honestly I think having the USB connector on this board is a waste of space and getting USB devices to show up on my PC is wasting time. I think I’ll opt to remove it as well as the WS2812 status LED. Keep it simple.