wip

.gitignore

@@ -0,0 +1 @@
+/target

.vscode/settings.json

@@ -0,0 +1,4 @@
+{
+    "editor.formatOnSave": true,
+    "rust-analyzer.check.command": "clippy"
+}

.vscode/tasks.json

@@ -0,0 +1,15 @@
+{
+	"version": "2.0.0",
+	"tasks": [
+		{
+			"type": "process",
+			"command": "cross",
+			"args": ["build", "--target","arm-unknown-linux-gnueabihf"],
+			"problemMatcher": [
+				"$rustc"
+			],
+			"group": "build",
+			"label": "rust: cargo build"
+		}
+	]
+} 

Cargo.lock

@@ -0,0 +1,67 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "bitflags"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf4b9d6a944f767f8e5e0db018570623c85f3d925ac718db4e06d0187adb21c1"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "cfg_aliases"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
+
+[[package]]
+name = "interrupts"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1ccb0bdc9cefc5772ebc23d9bd94aabf408ab6753735f1936ac6ed7e714c8c6"
+dependencies = [
+ "cfg-if",
+ "nix",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.153"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c198f91728a82281a64e1f4f9eeb25d82cb32a5de251c6bd1b5154d63a8e7bd"
+
+[[package]]
+name = "nix"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
+dependencies = [
+ "bitflags",
+ "cfg-if",
+ "cfg_aliases",
+ "libc",
+]
+
+[[package]]
+name = "rpitest"
+version = "0.1.0"
+dependencies = [
+ "interrupts",
+ "libc",
+ "rppal",
+]
+
+[[package]]
+name = "rppal"
+version = "0.17.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1dc171bbe325b04172e18d917c58c2cf1fb5adfd9ffabb1d6b3d62ba4c1c1331"
+dependencies = [
+ "libc",
+]

Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "rpitest"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+rppal = "0.17.1"
+#rumqttc = "0.24.0"
+interrupts = "0.1.5"
+libc = "0.2.153"

src/dht11.rs

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+use std::{
+    error::Error,
+    thread,
+    time::{Duration, Instant},
+};
+
+use rppal::gpio::Gpio;
+
+pub struct Dht11Data {
+    pub temperature: f32,
+    pub humidity: f32,
+}
+pub struct Dht11Sensor {
+    pin: rppal::gpio::IoPin,
+}
+impl Dht11Sensor {
+    pub fn new(pin: u8) -> Result<Dht11Sensor, Box<dyn Error>> {
+        let pin = Gpio::new()?.get(pin)?.into_io(rppal::gpio::Mode::Input);
+        Ok(Dht11Sensor { pin })
+    }
+
+    fn expect_pulse(&mut self, expected_level: bool) -> Result<Duration, Box<dyn Error>> {
+        let started = Instant::now();
+        loop {
+            if self.pin.is_high() != expected_level {
+                break;
+            }
+            if started.elapsed() >= Duration::from_micros(1000) {
+                return Err(std::io::Error::new(
+                    std::io::ErrorKind::InvalidData,
+                    "Timeout while reading pulse",
+                )
+                .into());
+            }
+
+            thread::sleep(Duration::from_micros(1));
+        }
+        Ok(started.elapsed())
+    }
+
+    pub fn read(&mut self) -> Result<Dht11Data, Box<dyn Error>> {
+        use rppal::gpio::{Bias, Mode};
+
+        let mut data = [0; 5];
+        let mut cycles: [Duration; 80] = [Duration::from_micros(0); 80];
+
+        let guard = interrupts::disable();
+
+        self.pin.set_mode(Mode::Input);
+        self.pin.set_bias(Bias::PullUp);
+        thread::sleep(Duration::from_millis(1));
+
+        self.pin.set_mode(Mode::Output);
+        self.pin.set_low();
+        thread::sleep(Duration::from_millis(20));
+
+        // Timing Critical Code
+        self.pin.set_mode(Mode::Input);
+        self.pin.set_bias(Bias::PullUp);
+        thread::sleep(Duration::from_micros(55));
+
+        self.expect_pulse(false)?;
+        self.expect_pulse(true)?;
+        for i in (0..80).step_by(2) {
+            cycles[i] = self.expect_pulse(false)?;
+            cycles[i + 1] = self.expect_pulse(true)?;
+        }
+
+        for i in 0..40 {
+            let low_cycles = cycles[2 * i];
+            let high_cycles = cycles[2 * i + 1];
+            data[i / 8] <<= 1;
+            if high_cycles > low_cycles {
+                data[i / 8] |= 1;
+            }
+        }
+
+        if data[4] != ((data[0] + data[1] + data[2] + data[3]) & 0xFF) {
+            return Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidData,
+                "DHT Checksum Failure",
+            )
+            .into());
+        }
+
+        let mut temperature = data[2] as f32;
+        if data[3] & 0x80 != 0 {
+            temperature = -1. - temperature;
+        }
+        temperature += ((data[3] & 0x0F) as f32) * 0.1;
+
+        let mut humidity = data[0] as f32;
+        humidity += (data[1] as f32) * 0.1;
+
+        Ok(Dht11Data {
+            temperature,
+            humidity,
+        })
+    }
+}

src/main.rs

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+use std::{error::Error, thread, time::Duration};
+
+use dht11::Dht11Sensor;
+
+mod dht11;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    unsafe {
+        libc::setpriority(libc::PRIO_PROCESS, 0, -20);
+    }
+    let mut sensor = Dht11Sensor::new(2)?;
+    loop {
+        match sensor.read() {
+            Ok(data) => println!(
+                "Humidity: {}; Temperature: {}",
+                data.humidity, data.temperature
+            ),
+            Err(msg) => println!("Error: {}", msg),
+        }
+        thread::sleep(Duration::from_millis(2000));
+    }
+
+    Ok(())
+}