Refactor for Support DHT11

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "dht-pio"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2021"
 
 license = "MIT"

readme.md

@@ -28,6 +28,6 @@ For the moment, the crates have only been tested on a Raspberry Pico.
 - [ ] Finish Readme
 - [x] Add CRC read
 - [x] Check CRC
-- [ ] DHT11 support
+- [x] DHT11 support
 - [ ] Test DHT11
 - [ ] Document code

readme_fr.md

@@ -31,6 +31,6 @@ Pour le moment le crates n'a été testé que sur un Raspberry Pico.
 - [ ] Finir le Readme
 - [x] Ajouter la lecture du CRC
 - [x] Vérifier le CRC
-- [ ] Support du DHT11
+- [x] Support du DHT11
 - [ ] Tester DHT11
 - [ ] Documenter le code

src/dht.rs

@@ -0,0 +1,92 @@
+use cortex_m::delay::Delay;
+use pio_proc::pio_file;
+use rp2040_hal::gpio::AnyPin;
+use rp2040_hal::pio::{PIOExt, Running, StateMachine, StateMachineIndex, Tx};
+use rp2040_hal::pio::{Rx, UninitStateMachine};
+
+use crate::DhtError;
+
+pub struct DhtPio<P: PIOExt, STI: StateMachineIndex> {
+    // sm: PicoStateMachine<P, STI>,
+    sm: StateMachine<(P, STI), Running>,
+    rx_fifo: Rx<(P, STI)>,
+    tx_fifo: Tx<(P, STI)>,
+}
+
+impl<P: PIOExt, STI: StateMachineIndex> DhtPio<P, STI> {
+    pub fn new<I: AnyPin<Function = P::PinFunction>>(
+        mut pio: rp2040_hal::pio::PIO<P>,
+        sm: UninitStateMachine<(P, STI)>,
+        dht_pin: I,
+    ) -> Self {
+        let program = pio_file!("./src/dht.pio");
+
+        let pin = dht_pin.into();
+
+        let installed = pio.install(&program.program).unwrap();
+
+        let (int, frac) = (125, 0);
+        let (mut sm, rx, tx) = rp2040_hal::pio::PIOBuilder::from_program(installed)
+            .set_pins(pin.id().num, 1)
+            .clock_divisor_fixed_point(int, frac)
+            .push_threshold(32)
+            .build(sm);
+        sm.set_pindirs([(pin.id().num, rp2040_hal::pio::PinDir::Output)]);
+
+        Self {
+            sm: sm.start(),
+            rx_fifo: rx,
+            tx_fifo: tx,
+        }
+    }
+
+    pub fn read_data(&mut self, delay: &mut Delay) -> Result<(u32, u32), DhtError> {
+        let mut timeout = 2000;
+        let mut raw: [Option<u32>; 2] = [None; 2];
+
+        self.tx_fifo.write(1);
+
+        while timeout > 0 && raw[1].is_none() {
+            match self.rx_fifo.read() {
+                Some(d) => {
+                    if raw[0].is_none() {
+                        raw[0] = Some(d);
+                    } else {
+                        raw[1] = Some(d);
+                    }
+                }
+                None => (),
+            }
+
+            delay.delay_ms(1);
+            timeout -= 1;
+        }
+
+        if timeout <= 0 {
+            self.sm.restart();
+            return Err(DhtError::Timeout);
+        }
+
+        let data = raw[0].unwrap();
+        let crc = raw[1].unwrap();
+
+        if Self::compute_crc(data) != crc {
+            return Err(DhtError::CrcMismatch(
+                raw[0].unwrap_or(0),
+                raw[1].unwrap_or(0),
+            ));
+        }
+
+        Ok((data & 0x0000FFFF, (data & 0xFFFF0000) >> 16))
+    }
+
+    fn compute_crc(data: u32) -> u32 {
+        let mut crc: u32 = 0;
+        crc += data & 0x000000FF;
+        crc += (data & 0x0000FF00) >> 8;
+        crc += (data & 0x00FF0000) >> 16;
+        crc += (data & 0xFF000000) >> 24;
+
+        crc % 256
+    }
+}

src/lib.rs

@@ -1,10 +1,12 @@
 #![no_std]
 
 use cortex_m::delay::Delay;
-use pio_proc::pio_file;
 use rp2040_hal::gpio::AnyPin;
-use rp2040_hal::pio::{PIOExt, Running, StateMachine, StateMachineIndex, Tx};
-use rp2040_hal::pio::{Rx, UninitStateMachine};
+use rp2040_hal::pio::UninitStateMachine;
+use rp2040_hal::pio::{PIOExt, StateMachineIndex};
+
+mod dht;
+use dht::DhtPio;
 
 #[derive(Debug)]
 pub enum DhtError {
@@ -22,94 +24,61 @@ pub struct DhtResult {
     pub humidity: f32,
 }
 
-pub struct DhtPio<P: PIOExt, STI: StateMachineIndex> {
-    // sm: PicoStateMachine<P, STI>,
-    sm: StateMachine<(P, STI), Running>,
-    rx_fifo: Rx<(P, STI)>,
-    tx_fifo: Tx<(P, STI)>,
+pub struct Dht22<P: PIOExt, STI: StateMachineIndex> {
+    dht: DhtPio<P, STI>,
 }
 
-impl<P: PIOExt, STI: StateMachineIndex> DhtPio<P, STI> {
+impl<P: PIOExt, STI: StateMachineIndex> Dht22<P, STI> {
     pub fn new<I: AnyPin<Function = P::PinFunction>>(
-        mut pio: rp2040_hal::pio::PIO<P>,
+        pio: rp2040_hal::pio::PIO<P>,
         sm: UninitStateMachine<(P, STI)>,
         dht_pin: I,
     ) -> Self {
-        let program = pio_file!("./src/dht.pio");
-
-        let pin = dht_pin.into();
-
-        let installed = pio.install(&program.program).unwrap();
-
-        let (int, frac) = (125, 0);
-        let (mut sm, rx, tx) = rp2040_hal::pio::PIOBuilder::from_program(installed)
-            .set_pins(pin.id().num, 1)
-            .clock_divisor_fixed_point(int, frac)
-            .push_threshold(32)
-            .build(sm);
-        sm.set_pindirs([(pin.id().num, rp2040_hal::pio::PinDir::Output)]);
-
         Self {
-            sm: sm.start(),
-            rx_fifo: rx,
-            tx_fifo: tx,
+            dht: DhtPio::new(pio, sm, dht_pin),
         }
     }
 
-    /// Read data from the sensor. This blocking function (for maximum timeout of 2 seconds).
-    pub fn read_data(&mut self, delay: &mut Delay) -> Result<DhtResult, DhtError> {
-        let mut timeout = 2000;
-        let mut raw: [Option<u32>; 2] = [None; 2];
+    pub fn read(&mut self, delay: &mut Delay) -> Result<DhtResult, DhtError> {
+        let (t, h) = self.dht.read_data(delay)?;
+        let mut final_t: i32 = (t & 0x7FFF) as i32;
 
-        self.tx_fifo.write(1);
-
-        while timeout > 0 && raw[1].is_none() {
-            match self.rx_fifo.read() {
-                Some(d) => {
-                    if raw[0].is_none() {
-                        raw[0] = Some(d);
-                    } else {
-                        raw[1] = Some(d);
+        if (t & 0x8000) > 0 {
+            final_t *= -1;
         }
-                }
-                None => (),
-            }
-
-            delay.delay_ms(1);
-            timeout -= 1;
-        }
-
-        if timeout <= 0 {
-            self.sm.restart();
-            return Err(DhtError::Timeout);
-        }
-
-        let data = raw[0].unwrap();
-        let crc = raw[1].unwrap();
-
-        if Self::compute_crc(data) != crc {
-            return Err(DhtError::CrcMismatch(
-                raw[0].unwrap_or(0),
-                raw[1].unwrap_or(0),
-            ));
-        }
-
-        let t_raw = data & 0x0000FFFF;
-        let h_raw = (data & 0xFFFF0000) >> 16;
 
         Ok(DhtResult {
-            temperature: t_raw as f32 / 10.0,
-            humidity: h_raw as f32 / 10.0,
+            temperature: final_t as f32 / 10.0,
+            humidity: h as f32 / 10.0,
         })
     }
+}
+pub struct Dht11<P: PIOExt, STI: StateMachineIndex> {
+    dht: DhtPio<P, STI>,
+}
 
-    fn compute_crc(data: u32) -> u32 {
-        let mut crc: u32 = 0;
-        crc += data & 0x000000FF;
-        crc += (data & 0x0000FF00) >> 8;
-        crc += (data & 0x00FF0000) >> 16;
-        crc += (data & 0xFF000000) >> 24;
-
-        crc % 256
+impl<P: PIOExt, STI: StateMachineIndex> Dht11<P, STI> {
+    pub fn new<I: AnyPin<Function = P::PinFunction>>(
+        pio: rp2040_hal::pio::PIO<P>,
+        sm: UninitStateMachine<(P, STI)>,
+        dht_pin: I,
+    ) -> Self {
+        Self {
+            dht: DhtPio::new(pio, sm, dht_pin),
+        }
+    }
+
+    pub fn read(&mut self, delay: &mut Delay) -> Result<DhtResult, DhtError> {
+        let (t, h) = self.dht.read_data(delay)?;
+        let mut final_t: i32 = ((t & 0x7FFF) >> 8) as i32;
+
+        if (t & 0x8000) > 0 {
+            final_t *= -1;
+        }
+
+        Ok(DhtResult {
+            temperature: final_t as f32,
+            humidity: (h >> 8) as f32,
+        })
     }
 }