How to save and pass 'PinDriver' objects

[xiaguangbo]

My basic idea is to encapsulate a onewire struct and pass a decimal pin number to drive the corresponding pin. But how do you preserve the objects returned by PinDriver: : input_output_od? I'm not gonna write this：

struch Onewire {
    pin : ???
};

...

let mut pin  = PinDriver::input_output_od(0) // Use numbers instead, and if no, use `match` a separate line for each peripheral.pins.gpiox.

now：

use esp_idf_hal::delay::FreeRtos;
use esp_idf_svc::hal::{
    delay::Delay,
    gpio::{PinDriver, Pull},
    peripherals::Peripherals,
};

fn main() {
    // It is necessary to call this function once. Otherwise some patches to the runtime
    // implemented by esp-idf-sys might not link properly. See https://github.com/esp-rs/esp-idf-template/issues/71
    esp_idf_svc::sys::link_patches();

    // Bind the log crate to the ESP Logging facilities
    esp_idf_svc::log::EspLogger::initialize_default();

    log::info!("Hello, world!");

    let peripherals = Peripherals::take().unwrap();

    let mut onewire = PinDriver::input_output_od(peripherals.pins.gpio0).unwrap();
    onewire.set_pull(Pull::Floating).unwrap(); // Use external pull-up

    let delay = Delay::new_default();

    loop {
        FreeRtos::delay_ms(1000);

        // reset
        onewire.set_low().unwrap();
        delay.delay_us(600);
        onewire.set_high().unwrap();
        delay.delay_us(80);

        if onewire.is_low() {
            log::info!("onewire: is exist");
            delay.delay_us(900);

            if onewire.is_high() {
                log::info!("onewire: reset ok");
            } else {
                log::warn!("onewire: reset err");
                continue;
            }
        } else {
            log::warn!("onewire: reset err");
            continue;
        }
    }
}

[Sergio Gasquez Arcos]

Hi! I would suggest using the matrix channel (https://matrix.to/#/#esp-rs:matrix.org) for this kind of questions as they are not issues per se and not strictly related with the training. Also, more people could jump in to help you.

[xiaguangbo]

Hi! I would suggest using the matrix channel (https://matrix.to/#/#esp-rs:matrix.org) for this kind of questions as they are not issues per se and not strictly related with the training. Also, more people could jump in to help you.

ok

[xiaguangbo]

is ok

use embedded_hal::digital;

use esp_idf_svc::hal::delay;
use esp_idf_svc::hal::gpio;
use esp_idf_svc::hal::peripherals;
use esp_idf_svc::hal::uart;
use esp_idf_svc::hal::units;

use std::fmt::Write;

const CMD_SKIP: u8 = 0xcc;
const CMD_WRITE_REG: u8 = 0x4e;
const CMD_TEMP_START: u8 = 0x44;
const CMD_READ_REG: u8 = 0xbe;

fn main() {
    // It is necessary to call this function once. Otherwise some patches to the runtime
    // implemented by esp-idf-sys might not link properly. See https://github.com/esp-rs/esp-idf-template/issues/71
    esp_idf_svc::sys::link_patches();

    // Bind the log crate to the ESP Logging facilities
    esp_idf_svc::log::EspLogger::initialize_default();

    log::info!("Hello, world!");

    let peripherals = peripherals::Peripherals::take().unwrap();

    // onewire
    let mut onewire = gpio::PinDriver::input_output_od(peripherals.pins.gpio0).unwrap();
    onewire.set_pull(gpio::Pull::Floating).unwrap(); // use external pull-up

    // uart
    let config = uart::config::Config::default().baudrate(units::Hertz(115_200));
    let mut uart = uart::UartDriver::new(
        peripherals.uart1,
        peripherals.pins.gpio1,
        peripherals.pins.gpio2,
        Option::<gpio::AnyIOPin>::None,
        Option::<gpio::AnyIOPin>::None,
        &config,
    )
    .unwrap();

    // delay
    let delay = delay::Delay::new_default();

    // ds18b20
    // wait reset
    while !onewire_reset(&mut onewire, &delay) {
        delay::FreeRtos::delay_ms(1000);
    }

    // set accuracy
    onewire_write_byte(&mut onewire, &delay, CMD_SKIP);
    onewire_write_byte(&mut onewire, &delay, CMD_WRITE_REG);
    onewire_write_byte(&mut onewire, &delay, 0xff);
    onewire_write_byte(&mut onewire, &delay, 0x00);
    onewire_write_byte(&mut onewire, &delay, 0x7f);

    loop {
        delay::FreeRtos::delay_ms(1000);

        // ds18b20
        // measurement temp
        if !onewire_reset(&mut onewire, &delay) {
            continue;
        }

        onewire_write_byte(&mut onewire, &delay, CMD_SKIP);
        onewire_write_byte(&mut onewire, &delay, CMD_TEMP_START);

        // read temp
        if !onewire_reset(&mut onewire, &delay) {
            continue;
        }

        onewire_write_byte(&mut onewire, &delay, CMD_SKIP);
        onewire_write_byte(&mut onewire, &delay, CMD_READ_REG);

        let temp_l = onewire_read_byte(&mut onewire, &delay);
        let temp_h = onewire_read_byte(&mut onewire, &delay);
        let temp = (((temp_h as i16) << 8 | (temp_l as i16)) as f64) * 0.0625;

        log::info!("temp: {:.1}", temp);

        // uart
        writeln!(uart, "temp: {:.1}", temp).unwrap();
    }
}

fn onewire_reset<T>(pin: &mut T, delay: &delay::Delay) -> bool
where
    T: digital::InputPin + digital::OutputPin,
{
    pin.set_low().unwrap();
    delay.delay_us(600);
    pin.set_high().unwrap();
    delay.delay_us(80);

    if pin.is_low().unwrap() {
        log::info!("onewire: is exist");
        delay.delay_us(900);

        if pin.is_high().unwrap() {
            log::info!("onewire: reset ok");
            true
        } else {
            log::warn!("onewire: reset err");
            false
        }
    } else {
        log::warn!("onewire: reset err");
        false
    }
}

fn onewire_write_byte<T>(pin: &mut T, delay: &delay::Delay, mut byte: u8)
where
    T: digital::InputPin + digital::OutputPin,
{
    for _ in 0..8 {
        let bit = byte & 0x01 != 0;
        byte >>= 1;

        if bit {
            pin.set_low().unwrap();
            delay.delay_us(5);

            pin.set_high().unwrap();
            delay.delay_us(90);
        } else {
            pin.set_low().unwrap();
            delay.delay_us(90);

            pin.set_high().unwrap();
            delay.delay_us(5);
        }
    }
}

fn onewire_read_byte<T>(pin: &mut T, delay: &delay::Delay) -> u8
where
    T: digital::InputPin + digital::OutputPin,
{
    let mut byte: u8 = 0;

    for _ in 0..8 {
        byte >>= 1;

        pin.set_low().unwrap();
        delay.delay_us(5);

        pin.set_high().unwrap();
        delay.delay_us(5);

        if pin.is_high().unwrap() {
            byte |= 0x80;
        }

        delay.delay_us(60);
    }

    byte
}