#![feature(used)]
#![no_std]
extern crate stm32f042_hal as hal;
use hal::prelude::*;
use hal::stm32f042;
#[macro_use(block)]
extern crate nb;
use hal::serial::Serial;
fn main() {
if let Some(p) = stm32f042::Peripherals::take() {
let gpioa = p.GPIOA.split();
let mut rcc = p.RCC.constrain();
let clocks = rcc.cfgr.sysclk(48.mhz()).freeze();
let tx = gpioa.pa9.into_alternate_af1();
let rx = gpioa.pa10.into_alternate_af1();
let serial = Serial::usart1(
p.USART1,
(tx, rx),
115_200.bps(),
clocks,
);
let (mut tx, mut rx) = serial.split();
loop {
let received = block!(rx.read()).unwrap();
block!(tx.write(received)).ok();
}
}
}