esp-hal/esp32h2-hal/examples/spi_loopback.rs

//! SPI loopback test
//!
//! Folowing pins are used:
//! SCLK    GPIO1
//! MISO    GPIO2
//! MOSI    GPIO3
//! CS      GPIO11
//!
//! Depending on your target and the board you are using you have to change the
//! pins.
//!
//! This example transfers data via SPI.
//! Connect MISO and MOSI pins to see the outgoing data is read as incoming
//! data.

#![no_std]
#![no_main]

use esp32h2_hal::{
    clock::ClockControl,
    gpio::IO,
    peripherals::Peripherals,
    prelude::*,
    spi::{master::Spi, SpiMode},
    Delay,
};
use esp_backtrace as _;
use esp_println::println;

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

    let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);
    let sclk = io.pins.gpio1;
    let miso = io.pins.gpio2;
    let mosi = io.pins.gpio3;
    let cs = io.pins.gpio11;

    let mut spi = Spi::new(peripherals.SPI2, 100u32.kHz(), SpiMode::Mode0, &clocks).with_pins(
        Some(sclk),
        Some(mosi),
        Some(miso),
        Some(cs),
    );

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

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

        delay.delay_ms(250u32);
    }
}