Fix line requests in take_measurement

Cargo.toml

@@ -23,6 +23,7 @@ rppal = { version = "0.13.1", features = ["hal"] }
 ssd1351 = { git = "https://github.com/FliegendeWurst/ssd1351-rust" }
 display-interface-spi = "0.4.1"
 ureq = { version = "2.4.0", default-features = false }
+#gpio-am2302-rs = { git = "https://github.com/FliegendeWurst/gpio-am2302-rs" }
 
 [profile.release]
 codegen-units = 1

src/bin/take_measurement.rs

@@ -31,6 +31,10 @@ fn main() {
 		.unwrap();
 	while temps.len() < 5 && attempts < 10 {
 		if let Ok((rh, temp)) = raspi_oled::am2302_reading(&line) {
+			// TODO: try out gpio_am2302_rs!
+			//if let Ok(reading) = gpio_am2302_rs::try_read(26) {
+			//let rh = reading.humidity as i64;
+			//let temp = (reading.temperature * 10.0) as i64;
 			if rh > 0 && temp < 500 {
 				rhs.push(rh);
 				temps.push(temp);
@@ -43,10 +47,13 @@ fn main() {
 		// median = hopefully no faulty readings
 		temps.sort();
 		rhs.sort();
+		let rh = rhs[rhs.len() / 2];
+		let temp = temps[temps.len() / 2];
+		println!("info: acquired {} readings (temps {:?}, rhs {:?}), using rh {} and temp {}", temps.len(), temps, rhs, rh, temp);
 		database
 			.execute(
 				"INSERT INTO sensor_readings (time, humidity, celsius) VALUES (?1, ?2, ?3)",
-				params![time.as_secs(), rhs[rhs.len() / 2], temps[temps.len() / 2]],
+				params![time.as_secs(), rh, temp],
 			)
 			.unwrap();
 	}

src/lib.rs

@@ -76,6 +76,7 @@ fn read_events(line: &gpio_cdev::Line, timeout: std::time::Duration) -> Result<V
 		}
 	}
 	if events.len() < 81 {
+		println!("error: only got {} events", events.len());
 		return Err(SensorError::Timeout);
 	}
 	Ok(events)
@@ -162,15 +163,14 @@ impl From<gpio_cdev::Error> for SensorError {
 }
 
 pub fn am2302_reading(line: &Line) -> Result<(u16, u16), SensorError> {
-	line.request(LineRequestFlags::OUTPUT, 1, "rust-am2302").unwrap();
+	let out = line.request(LineRequestFlags::OUTPUT, 1, "rust-am2302").unwrap();
+	out.set_value(1)?;
 	sleep(Duration::from_millis(500));
 	set_max_priority();
 	// set low for 20 ms
-	if let Err(e) = line.request(LineRequestFlags::OUTPUT, 0, "rust-am2302") {
-		set_normal_priority();
-		return Err(SensorError::Io(e));
-	}
+	out.set_value(0)?;
 	sleep(Duration::from_millis(3));
+	drop(out);
 
 	let events = read_events(&line, Duration::from_secs(1));
 	println!("{:?} {:?}", events, events.as_ref().map(|x| x.len()));