Add BME280 logic

Cargo.toml

@@ -2,4 +2,12 @@
 name = "room-monitor"
 version = "0.1.0"
 
-[dependencies]
+[dependencies]
+anyhow = "1.0.75"
+env_logger = "0.10.1"
+log = "0.4.20"
+mockall = "0.11.4"
+
+[target.'cfg(target_os = "linux")'.dependencies]
+bme280 = "0.4.4"
+linux-embedded-hal = "0.4.0-alpha.2"

Dockerfile

@@ -1,8 +1,8 @@
-FROM rust:1.67 as builder
+FROM rust:latest as builder
 WORKDIR /usr/src/myapp
 COPY . .
 RUN cargo install --path .
 
-FROM debian:bullseye-slim
+FROM debian
 COPY --from=builder /usr/local/cargo/bin/room-monitor /usr/local/bin/room-monitor
 CMD ["room-monitor"]

src/driver/linux.rs

@@ -0,0 +1,36 @@
+extern crate bme280;
+extern crate linux_embedded_hal as hal;
+
+use super::{BME280Driver, Readings};
+
+pub struct LinuxBME280Driver {
+    bme280: bme280::i2c::BME280<hal::I2cdev>,
+}
+
+impl LinuxBME280Driver {
+    pub fn new() -> anyhow::Result<Self> {
+        match hal::I2cdev::new("/dev/i2c-1") {
+            Ok(i2c_bus) => {
+                let mut bme280 = bme280::i2c::BME280::new_primary(i2c_bus);
+                match bme280.init(&mut hal::Delay) {
+                    Ok(_) => Ok(Self { bme280 }),
+                    Err(_) => Err(anyhow::anyhow!("Failed to init BME280.")),
+                }
+            }
+            Err(_) => Err(anyhow::anyhow!("Failed to open I2C bus.")),
+        }
+    }
+}
+
+impl BME280Driver for LinuxBME280Driver {
+    fn read(&mut self) -> anyhow::Result<Readings> {
+        match self.bme280.measure(&mut hal::Delay) {
+            Ok(measurements) => Ok(Readings {
+                temperature: measurements.temperature,
+                pressure: measurements.pressure,
+                humidity: measurements.humidity,
+            }),
+            Err(_) => Err(anyhow::anyhow!("Failed to read measurements.")),
+        }
+    }
+}

src/driver/mod.rs

@@ -0,0 +1,32 @@
+#[cfg(target_os = "linux")]
+pub mod linux;
+
+#[cfg(target_os = "linux")]
+pub fn get_bme280_driver() -> anyhow::Result<impl BME280Driver> {
+    Ok(linux::LinuxBME280Driver::new()?)
+}
+
+#[cfg(not(target_os = "linux"))]
+pub fn get_bme280_driver() -> anyhow::Result<impl BME280Driver> {
+    let mut driver = MockBME280Driver::new();
+    driver.expect_read().returning(|| {
+        Ok(Readings {
+            temperature: 18.5,
+            pressure: 1013.25,
+            humidity: 45.0,
+        })
+    });
+
+    Ok(driver)
+}
+
+pub struct Readings {
+    pub temperature: f32,
+    pub pressure: f32,
+    pub humidity: f32,
+}
+
+#[mockall::automock]
+pub trait BME280Driver {
+    fn read(&mut self) -> anyhow::Result<Readings>;
+}

src/main.rs

@@ -1,3 +1,59 @@
+pub mod driver;
+
+use driver::{get_bme280_driver, BME280Driver};
+use std::thread::sleep;
+use std::time::Duration;
+
+const LOOP_RATE_S: u64 = 1;
+
 fn main() {
-    println!("Hello, world!");
+    setup_logging();
+
+    log::info!("Application started");
+
+    let driver = get_bme280_driver().expect("Failed to get BME280 driver");
+    let mut runner = Runner::new(driver);
+
+    loop {
+        if let Err(e) = runner.step() {
+            log::error!("Error steppinf runner: {}", e);
+        }
+
+        sleep(Duration::from_secs(LOOP_RATE_S));
+    }
+}
+
+fn setup_logging() {
+    let mut builder = env_logger::Builder::from_default_env();
+    builder
+        .filter_level(log::LevelFilter::Debug)
+        .target(env_logger::Target::Stdout)
+        .init();
+}
+
+struct Runner<T>
+where
+    T: BME280Driver,
+{
+    driver: T,
+}
+
+impl<T> Runner<T>
+where
+    T: BME280Driver,
+{
+    fn new(driver: T) -> Self {
+        Self { driver }
+    }
+
+    fn step(&mut self) -> anyhow::Result<()> {
+        let readings = self.driver.read()?;
+        log::info!(
+            "{} degC,\t {} hPa,\t {} %",
+            readings.temperature,
+            readings.pressure,
+            readings.humidity
+        );
+        Ok(())
+    }
 }