#![feature(used, asm)]
#![no_std]
#![no_main]

extern crate circuit_playground_express as hal;
extern crate panic_abort;

#[macro_use(entry)]
extern crate cortex_m_rt;

use hal::clock::GenericClockController;
use hal::delay::Delay;
use hal::prelude::*;
use hal::{CorePeripherals, Peripherals};

entry!(main);

fn main() -> ! {
    let mut peripherals = Peripherals::take().unwrap();
    let core = CorePeripherals::take().unwrap();
    let mut clocks = GenericClockController::with_internal_32kosc(
        peripherals.GCLK,
        &mut peripherals.PM,
        &mut peripherals.SYSCTRL,
        &mut peripherals.NVMCTRL,
    );
    let mut pins = hal::Pins::new(peripherals.PORT);
    let mut neopixel = pins.neopixel.into_open_drain_output(&mut pins.port);
    let mut delay = Delay::new(core.SYST, &mut clocks);

    let pixels: [u8;3] = [0xff, 0x00, 0x00];
    let mut counter: usize = 0;
    let mut p: u8 = pixels[counter];
    counter += 1;
    let mut bitmask: u8 = 0x80;

    loop {
        neopixel.set_high();
        unsafe{ 
            asm!("nop; nop; nop; nop; nop; nop; nop; nop;
                    nop; nop; nop;");
        }
        if p & bitmask != 0 {
            unsafe{ 
                asm!("nop; nop; nop; nop; nop; nop; nop; nop;
                        nop; nop; nop; nop; nop; nop; nop; nop;
                        nop; nop; nop; nop; nop; nop; nop; nop;
                        nop; nop; nop;");
            }
            neopixel.set_low();
        } else {
            neopixel.set_low();
            unsafe{ 
                asm!("nop; nop; nop; nop; nop; nop; nop; nop;
                        nop; nop; nop; nop; nop; nop; nop; nop;
                        nop; nop; nop; nop; nop; nop; nop; nop;
                        nop; nop; nop;");
            }
        }
        unsafe { 
            asm!("nop; nop; nop; nop; nop; nop; nop; nop;
                    nop; nop; nop; nop; nop; nop; nop; nop;
                    nop; nop; nop; nop; nop; nop; nop; nop;
                    nop; nop; nop; nop; nop; nop; nop; nop;");
        }
        bitmask >>= 1;
        if bitmask != 0 {
            unsafe {
                asm!("nop; nop; nop; nop; nop; nop; nop;");
            }
        } else {
            if counter >= pixels.len() {
                break;
            }
            p = pixels[counter];
            counter += 1;
            bitmask = 0x80;
        }
    }
    loop {}
}