/*
For a detailed explanation of this code check out the associated blog post:
https://apollolabsblog.hashnode.dev/esp32-embedded-rust-at-the-hal-spi-communication

GitHub Repo containing source code and other examples:
https://github.com/apollolabsdev

For notifications on similar examples and more, subscribe to newsletter here:
https://www.theembeddedrustacean.com/subscribe
*/

#![no_std]
#![no_main]

use esp32c3_hal::{
    clock::ClockControl,
    gpio::IO,
    peripherals::Peripherals,
    prelude::*,
    spi::{Spi, SpiMode},
    timer::TimerGroup,
    Delay,
    Rtc,
};
use esp_backtrace as _;
use esp_println::println;

#[entry]
fn main() -> ! {
    let peripherals = Peripherals::take();
    let mut system = peripherals.SYSTEM.split();
    let clocks = ClockControl::boot_defaults(system.clock_control).freeze();

    // Disable the watchdog timers
    let mut rtc = Rtc::new(peripherals.RTC_CNTL);
    let timer_group0 = TimerGroup::new(
        peripherals.TIMG0,
        &clocks,
        &mut system.peripheral_clock_control,
    );
    let mut wdt0 = timer_group0.wdt;
    let timer_group1 = TimerGroup::new(
        peripherals.TIMG1,
        &clocks,
        &mut system.peripheral_clock_control,
    );
    let mut wdt1 = timer_group1.wdt;

    rtc.swd.disable();
    rtc.rwdt.disable();
    wdt0.disable();
    wdt1.disable();

    let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);
    let sclk = io.pins.gpio7;
    let miso = io.pins.gpio6;
    let mosi = io.pins.gpio5;
    let cs = io.pins.gpio4;

    let mut spi = Spi::new(
        peripherals.SPI2,
        sclk,
        mosi,
        miso,
        cs,
        25u32.kHz(),
        SpiMode::Mode0,
        &mut system.peripheral_clock_control,
        &clocks,
    );

    let mut delay = Delay::new(&clocks);

    loop {
        // One array single transfer
        //let mut data = [0xde, 0xca, 0xad];
        // spi.transfer(&mut data).unwrap();
        // println!("{:x?}", data);

        // Individual arrays multiple transfers
        let mut data = [0xde];
        spi.transfer(&mut data).unwrap();
        println!("{:x?}", data);
        let mut data = [0xca];
        spi.transfer(&mut data).unwrap();
        println!("{:x?}", data);
        let mut data = [0xad];
        spi.transfer(&mut data).unwrap();
        println!("{:x?}", data);
        delay.delay_ms(100u32);
    }
}