A platform agnostic driver to interface with the HC-SR04 (ultrasonic distance)
- Platform agnostic using
embedded-haltraits - Support for both blocking and non-blocking measurements
- Distance measurements with accurate timing using embedded clocks
Add this to your Cargo.toml:
[dependencies]
hc-sr04 = "0.2.0"For a complete working example using ESP32, check out the examples/esp32-example directory. Here's a basic demonstration of how to use the HC-SR04 ultrasonic distance sensor with the esp-idf-hal crate:
use esp_idf_hal::{delay::Delay, peripherals::Peripherals};
use hc_sr04::HcSr04;
use log::{error, info};
// Create clock implementation for ESP32
struct SystemClock;
impl embedded_timers::clock::Clock for SystemClock {
type Instant = embedded_timers::instant::Instant32<1_000_000>;
fn now(&self) -> Self::Instant {
embedded_timers::instant::Instant32::new(unsafe {
esp_idf_sys::esp_timer_get_time() as u32
})
}
}
// Initialize sensor with ESP32 pins
let peripherals = Peripherals::take().unwrap();
let echo_pin = esp_idf_hal::gpio::PinDriver::input(pins.gpio9).unwrap();
let trigger_pin = esp_idf_hal::gpio::PinDriver::output(pins.gpio10).unwrap();
let clock = SystemClock;
let delay = Delay::new(1000);
let mut sensor = HcSr04::new(trigger_pin, echo_pin, clock, delay);
// Take measurements
match sensor.measure() {
Ok(distance) => info!("Distance: {} cm ({} mm)", distance.cm(), distance.mm()),
Err(e) => error!("Error: {:?}", e),
}The driver triggers the HC-SR04 sensor and measures the duration of the echo pulse to calculate distance. It supports:
- Trigger pulse generation
- Echo pulse timing measurement
- Distance calculation
- Error handling for timeout and pin failures
Licensed under either of
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.