Added NFC implementation into refactored structure

src/drivers/nfc_pn532.rs

@@ -1 +1,118 @@
-// Drivers nfc_pn532 module
+use core::convert::Infallible;
+use esp_hal::gpio::interconnect::{PeripheralInput, PeripheralOutput};
+use esp_hal::i2c::master::{Config as I2cConfig, I2c};
+use esp_hal::peripherals::I2C0;
+use esp_hal::time::{Duration, Instant, Rate};
+use log::{error, info};
+use pn532::i2c::I2CInterface;
+use pn532::requests::SAMMode;
+use pn532::{nb, Pn532, Request};
+
+/// Timer implementation required by `pn532::CountDown`.
+pub struct TimerWrapper {
+    start: Instant,
+    duration: Duration,
+    counter: u32,
+}
+
+impl TimerWrapper {
+    pub fn new() -> Self {
+        Self {
+            start: Instant::now(),
+            duration: Duration::ZERO,
+            counter: 0,
+        }
+    }
+}
+
+impl Default for TimerWrapper {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl pn532::CountDown for TimerWrapper {
+    type Time = Duration;
+
+    fn start<T>(&mut self, timeout: T)
+    where
+        T: Into<Self::Time>,
+    {
+        // without this debug log, it works worse: stuck in NFC card search without ever returning.
+        self.start = esp_println::dbg!(Instant::now());
+        self.duration = timeout.into();
+        self.counter = 0;
+    }
+
+    fn wait(&mut self) -> nb::Result<(), Infallible> {
+        let elapsed = self.start.elapsed();
+        self.counter += 1;
+        if self.counter.is_multiple_of(1) {
+            info!("Elapsed: {elapsed}");
+        }
+        if elapsed >= self.duration {
+            Ok(())
+        } else {
+            Err(nb::Error::WouldBlock)
+        }
+    }
+}
+
+pub type Pn532Device<'a> = Pn532<I2CInterface<I2c<'a, esp_hal::Blocking>>, TimerWrapper, 32>;
+
+/// PN532 NFC reader driver.
+pub struct NfcPn532Driver<'a> {
+    pn532: Pn532Device<'a>,
+}
+
+impl<'a> NfcPn532Driver<'a> {
+    pub fn new<SDA, SCL>(i2c0: I2C0<'static>, sda: SDA, scl: SCL) -> Self
+    where
+        SDA: PeripheralInput<'static> + PeripheralOutput<'static>,
+        SCL: PeripheralInput<'static> + PeripheralOutput<'static>,
+    {
+        let config = I2cConfig::default().with_frequency(Rate::from_khz(100));
+        let i2c = I2c::new(i2c0, config)
+            .expect("Failed to init I2C")
+            .with_sda(sda)
+            .with_scl(scl);
+
+        let pn532 = Pn532::new(I2CInterface { i2c }, TimerWrapper::new());
+        Self { pn532 }
+    }
+
+    pub fn configure_sam(&mut self, timeout: Duration) -> Result<(), ()> {
+        if let Err(e) = self.pn532.process(
+            &Request::sam_configuration(SAMMode::Normal, false),
+            0,
+            timeout,
+        ) {
+            error!("Could not initialize PN532: {e:?}");
+            Err(())
+        } else {
+            info!("Successfully init'ed PN532");
+            Ok(())
+        }
+    }
+
+    pub fn read_card(&mut self, timeout: Duration) -> Option<[u8; 4]> {
+        if let Ok(uid) = self.pn532.process(&Request::INLIST_ONE_ISO_A_TARGET, 7, timeout) {
+            info!("uid = {uid:?}");
+            if let Ok(result) = self.pn532.process(&Request::ntag_read(10), 17, timeout) {
+                info!("page 10: {:?}", &result[1..5]);
+                let mut data = [0u8; 4];
+                data.copy_from_slice(&result[1..5]);
+                Some(data)
+            } else {
+                None
+            }
+        } else {
+            info!("No NFC card found.");
+            None
+        }
+    }
+
+    pub fn device_mut(&mut self) -> &mut Pn532Device<'a> {
+        &mut self.pn532
+    }
+}