Refactor DHT11 sensor handling and ensure safe GPIO pin state on drop

src/dht11.rs

@@ -20,6 +20,7 @@ pub enum Error<E> {
 /// A DHT11 device.
 pub struct Dht11<GPIO, D>
 where
+    GPIO: InputPin + OutputPin,
     D: DelayNs,
 {
     /// The concrete GPIO pin implementation.
@@ -118,3 +119,15 @@ where
         Ok(u32::from(count))
     }
 }
+
+impl<GPIO, D, E> Drop for Dht11<GPIO, D>
+where
+    GPIO: InputPin<Error = E> + OutputPin<Error = E>,
+    D: DelayNs,
+{
+    fn drop(&mut self) {
+        // Set pin high (floating with pull-up) as safe state
+        // Ignore errors during drop
+        let _ = self.gpio.set_high();
+    }
+}

src/sensors_task.rs

@@ -38,16 +38,12 @@ pub struct SensorPeripherals {
 #[embassy_executor::task]
 pub async fn sensor_task(
     sender: Sender<'static, NoopRawMutex, SensorData, 3>,
-    p: SensorPeripherals,
+    mut p: SensorPeripherals,
 ) {
     info!("Create");
 
-    let dht11_pin = OutputOpenDrain::new(p.dht11_pin, Level::High, Pull::None);
-
     let delay = Delay::new();
 
-    let mut dht11_sensor = Dht11::new(dht11_pin, delay);
-
     let mut adc2_config = AdcConfig::new();
     let mut moisture_pin = adc2_config
         .enable_pin_with_cal::<_, AdcCalCurve<ADC2>>(p.moisture_analog_pin, Attenuation::_11dB);
@@ -70,6 +66,9 @@ pub async fn sensor_task(
         let mut battery_voltage_samples: vec::Vec<u16> = vec![];
         let mut water_level_samples: vec::Vec<u16> = vec![];
 
+        let dht11_pin = OutputOpenDrain::new(&mut p.dht11_pin, Level::High, Pull::None);
+        let mut dht11_sensor: Dht11<OutputOpenDrain<'_>, Delay> = Dht11::new(dht11_pin, delay);
+
         for i in 0..SENSOR_SAMPLE_COUNT {
             info!("Reading sensor data {}/{}", (i + 1), SENSOR_SAMPLE_COUNT);