main.rs

#![no_main]
#![no_std]

use panic_halt as _;

use core::fmt::Write;
use cortex_m_rt::entry;

use rtt_target::rtt_init;

#[entry]
fn main() -> ! {
    let channels = rtt_init! {
        up: {
            0: {
                size: 512
                mode: BlockIfFull
                name: "Up zero"
            }
            1: {
                size: 128
                name: "Up one"
            }
            2: {
                size: 128
                name: "Up two"
            }
        }
        down: {
            0: {
                size: 512
                mode: BlockIfFull
                name: "Down zero"
            }
        }
    };

    let mut output2 = channels.up.1;
    writeln!(
        output2,
        "Hi! I will turn anything you type on channel 0 into upper case."
    )
    .ok();

    let mut output = channels.up.0;
    let mut log = channels.up.2;
    let mut input = channels.down.0;
    let mut buf = [0u8; 512];

    if let Some(p) = microbit::Peripherals::take() {
        p.GPIO.pin_cnf[4].write(|w| w.dir().output());
        p.GPIO.pin_cnf[13].write(|w| w.dir().output());

        p.GPIO.out.write(|w| unsafe { w.bits(1 << 13) });

        let mut count: u8 = 0;
        loop {
            let bytes = input.read(&mut buf[..]);
            if bytes > 0 {
                for c in buf.iter_mut() {
                    c.make_ascii_uppercase();
                }

                let mut p = 0;
                while p < bytes {
                    p += output.write(&buf[p..bytes]);
                }
            }

            writeln!(log, "Messsge no. {}/{}\nKEKEKE\nKEKEKEKE\nKEKEKEKkasdflasdfasdflkjasdkfljasdlkfölkasjflkasdjflöasjdlfjasdlkjflkasdjfklasdjflasjdflkasd", count, bytes).ok();

            count += 1;

            if count & 1 == 1 {
                p.GPIO.out.write(|w| unsafe { w.bits(1 << 13) });
            } else {
                p.GPIO.out.write(|w| unsafe { w.bits(0) });
            }

            for _ in 0..1_000_000 {
                cortex_m::asm::nop();
            }
        }
    };

    loop {
        continue;
    }
}