//! Template project for Rust on ESP32-S3 (`no_std`) based on [`esp-hal`](https://github.com/esp-rs/esp-hal)
//!
//! Useful resources:
//! - [The Rust on ESP Book](https://docs.esp-rs.org/book/)
//! - [Embedded Rust (no_std) on Espressif](https://docs.esp-rs.org/no_std-training/)
//! - [Matrix channel](https://matrix.to/#/#esp-rs:matrix.org)

#![no_std]
#![no_main]

use log::info;
use esp_hal::{
    //adc::{Adc, AdcConfig, Attenuation},
    analog::adc::{Adc, AdcConfig},
    //clock::ClockControl, // aux clock
    clock::CpuClock // primary clock
    delay::Delay, 
    gpio::IO,
    peripherals::Peripherals,
    prelude::*,
    system::SystemControl,
    // main
};

// use esp_backtrace as _; // Required to handle panics

// This creates a default app-descriptor required by the esp-idf bootloader.
// For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
// esp_bootloader_esp_idf::esp_app_desc!();

// Steinhart-Hart coefficients for a 10k NTC thermistor
const A: f32 = 0.001129148;
const B: f32 = 0.000234125;
const C: f32 = 0.0000000876741;

#[entry]
fn main() -> ! {
    let config = esp_hal::Config::default().with_cpu_clock(CpuClock::max());
    let _peripherals = esp_hal::init(config); // primary peripheral initialization

    let delay = Delay::new(); // primary delay initialization

//    esp_println::logger::init_logger_from_env();

        info!("Hello world!");
  
    //let peripherals = Peripherals::take(); // aux peripheral initialization
    let system = peripherals.SYSTEM.split();

    let clocks = ClockControl::boot_defaults(system.clock_control).freeze(); // Setup and freeze clocks
    //let mut delay = Delay::new(&clocks); // aux delay initialization

    let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);
    let analog_pin = io.pins.gpio4.into_analog(); // Connect your NTC to GPIO4
    let mut adc = Adc::new(peripherals.SENS, AdcConfig::new());

    loop {
        // Read raw ADC value (0–4095)
        let raw_adc = adc.read(&analog_pin).unwrap();
        // Convert ADC value to resistance of the thermistor
        let voltage_ratio = 4095.0 / raw_adc as f32 - 1.0;
        let resistance = 10_000.0 * voltage_ratio;
        // Apply Steinhart-Hart to get temperature in Kelvin, then Celsius
        let ln_r = resistance.ln();
        let temp_kelvin = 1.0 / (A + B * ln_r + C * ln_r.powi(3));
        let temp_celsius = temp_kelvin - 273.15;

        info!("its workin, temp is {}", temp_celsius);
        delay.delay_ms(2000u32);
    }
}