esp-hal/esp32-hal/examples/adc.rs

//! Connect a potentiometer to PIN25 and see the read values change when
//! rotating the shaft. Alternatively you could also connect the PIN to GND or
//! 3V3 to see the maximum and minimum raw values read.

#![no_std]
#![no_main]

use esp32_hal::{
    adc::{AdcConfig, Attenuation, ADC, ADC2},
    clock::ClockControl,
    gpio::IO,
    pac::Peripherals,
    prelude::*,
    timer::TimerGroup,
    Delay,
    Rtc,
};
use esp_backtrace as _;
use esp_println::println;
use xtensa_lx_rt::entry;

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

    let timer_group0 = TimerGroup::new(peripherals.TIMG0, &clocks);
    let mut wdt = timer_group0.wdt;
    let mut rtc = Rtc::new(peripherals.RTC_CNTL);

    // Disable MWDT and RWDT (Watchdog) flash boot protection
    wdt.disable();
    rtc.rwdt.disable();

    let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);
    let mut pin25 = io.pins.gpio25.into_analog();

    // Create ADC instances
    let analog = peripherals.SENS.split();

    let mut adc2_config = AdcConfig::new();
    adc2_config.enable_pin(&pin25, Attenuation::Attenuation11dB);
    let mut adc2 = ADC::<ADC2>::adc(analog.adc2, adc2_config).unwrap();

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

    loop {
        let pin25_value: u16 = nb::block!(adc2.read(&mut pin25)).unwrap();
        println!("PIN25 ADC reading = {}", pin25_value);
        delay.delay_ms(1500u32);
    }
}