esp32c3 运行 Rust(三)

上篇已经实现通过按钮控制 LED，现在让我们使用实现呼吸灯效果。

环境

OS: Ubuntu 20.04.4 LTS
Rust: rustc 1.62.0-nightly
IDE: VsCode
ESP32C3: ESP-C3-13-Kit 开发板

GPIO title
GPIO4 Green LED

GPIO	title
GPIO4	Green LED

创建项目

使用如下命令创建 ledc-simple 项目，并修改项目配置

cargo generate --git https://github.com/esp-rs/esp-idf-template cargo

创建细节参见 esp32c3 运行 Rust(〇) 中 创建项目 HelloWorld。

让 LED 闪烁起来吧

安装相关依赖

在 Cargo.toml 中添加相关依赖

embedded-hal 嵌入式系统的硬件抽象层
esp-idf-hal ESP32[-XX] + ESP-IDF 的 embedded-hal 实现
anyhow

# ...
[dependencies]
# ...
esp-idf-sys = { version = "0.31.1", features = ["binstart"] }
embedded-hal = "0.2.7" # 添加这行
esp-idf-hal = "0.36.0" # 添加这行
anyhow = "1.0.57" #  添加这行
# ...

设置引脚

//...
use esp_idf_hal::peripherals::Peripherals;
//...

fn main() -> anyhow::Result<()> {
    //...
    let peripherals = Peripherals::take().unwrap();
    //...
}

生成 PWM 信号通道

//...
use esp_idf_hal::{
    ledc::{
        config::TimerConfig,
        Timer,
        Channel,
    }
};
//...
fn main() -> anyhow::Result<()> {
    //...
    // 定时器配置
    let config = TimerConfig::default().frequency(25.kHz().into());
    // 创建定时器
    let timer = Timer::new(peripherals.ledc.timer0, &config)?;
    // 创建 LED 控制输出通道
    let mut channel = Channel::new(peripherals.ledc.channel0, &timer, peripherals.pins.gpio4)?;
    //...
}

获取最大占空比
```
let max_duty = channel.get_max_duty();
```

设置新的占空比

for numerator in (0..max_duty).cycle() {
    println!("Duty {}/5", numerator);
    channel.set_duty(numerator)?;
    FreeRtos.delay_us(1000_u16);
}

编译并上传

连接开发板，使用如下命令编译并上传
```
cargo espflash --release --monitor /dev/ttyUSB0
```

完整代码

use esp_idf_sys as _; // If using the `binstart` feature of `esp-idf-sys`, always keep this module imported

use embedded_hal::blocking::delay::DelayUs;

use esp_idf_hal::{
    delay::FreeRtos,
    ledc::{config::TimerConfig, Channel, Timer},
    peripherals::Peripherals,
    prelude::*,
};

use anyhow;
fn main() -> anyhow::Result<()> {
    // Temporary. Will disappear once ESP-IDF 4.4 is released, but for now it is necessary to call this function once,
    // or else some patches to the runtime implemented by esp-idf-sys might not link properly.
    esp_idf_sys::link_patches();
    
    println!("configuring output channel");

    let peripherals = Peripherals::take().unwrap();
    let config = TimerConfig::default().frequency(25.kHz().into());
    let timer = Timer::new(peripherals.ledc.timer0, &config)?;
    let mut channel = Channel::new(peripherals.ledc.channel0, &timer, peripherals.pins.gpio4)?;

    println!("Starting duty-cycle loop");
    let max_duty = channel.get_max_duty();
    for numerator in (0..max_duty).cycle() {
        println!("Duty {}/5", numerator);
        channel.set_duty(numerator)?;
        FreeRtos.delay_us(1000_u16);
    }
    
    loop {
        FreeRtos.delay_us(1000_u16);
    }
}

呼吸灯效果

已经实现了 LED 灯由灭变亮的渐变效果，现在实现由亮变灭的效果。完整代码如下

use esp_idf_sys as _; // If using the `binstart` feature of `esp-idf-sys`, always keep this module imported

use embedded_hal::blocking::delay::DelayUs;

use esp_idf_hal::{
  delay::FreeRtos,
  ledc::{config::TimerConfig, Channel, Timer},
  peripherals::Peripherals,
  prelude::*,
};

use anyhow;
fn main() -> anyhow::Result<()> {
  // Temporary. Will disappear once ESP-IDF 4.4 is released, but for now it is necessary to call this function once,
  // or else some patches to the runtime implemented by esp-idf-sys might not link properly.
  esp_idf_sys::link_patches();

  let peripherals = Peripherals::take().unwrap();
  let config = TimerConfig::default().frequency(25.kHz().into());
  let timer = Timer::new(peripherals.ledc.timer0, &config)?;
  let mut channel = Channel::new(peripherals.ledc.channel0, &timer, peripherals.pins.gpio4)?;

  let max_duty = channel.get_max_duty();
  
  loop {
    for numerator in 0..max_duty {
      channel.set_duty(numerator)?;
      FreeRtos.delay_us(10000_u16);
    }
    FreeRtos.delay_us(10000_u16);
    for numerator in (0..max_duty).rev() {
      channel.set_duty(numerator)?;
      FreeRtos.delay_us(10000_u16);
    }
    FreeRtos.delay_us(10000_u16);
  }
}

esp32c3 运行 Rust(三)

esp32c3 运行 Rust(三)

环境

创建项目

让 LED 闪烁起来吧

完整代码

呼吸灯效果

参考