pin level agnostic

2sem_sem2/.gitignore

@@ -1 +1,2 @@
 /target
+x.txt

2sem_sem2/src/bin/main.rs

@@ -11,12 +11,13 @@ use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
 use embassy_sync::channel::Channel;
 use embassy_time::Duration;
 use semestralka2::receive::bit_receive_and_decode;
-use semestralka2::send::nrz;
+use semestralka2::level_for_bit;
 use semestralka2::send::Tx;
+use semestralka2::send::{bit_send, msg_encode};
 
 use {defmt_rtt as _, panic_probe as _};
 
-static PIPE: Channel<CriticalSectionRawMutex, u8, 128> = Channel::new();
+static PIPE_SEND: Channel<CriticalSectionRawMutex, u8, 128> = Channel::new();
 static PIPE_REC: Channel<CriticalSectionRawMutex, u8, 128> = Channel::new();
 // static REC_ALLOWED: AtomicBool = AtomicBool::new(true);
 
@@ -25,22 +26,31 @@ async fn main(spawner: Spawner) {
     info!("tititititi");
 
     let p = embassy_stm32::init(Default::default());
-    let tx = Output::new(p.PF2, gpio::Level::High, gpio::Speed::VeryHigh);
+    let tx = Output::new(
+        p.PF2,
+        if level_for_bit(1) {
+            gpio::Level::High
+        } else {
+            gpio::Level::Low
+        },
+        gpio::Speed::VeryHigh,
+    );
     let rx = ExtiInput::new(p.PA3, p.EXTI3, Pull::Up);
 
-    let sender = PIPE.sender();
-    let receiver = PIPE.receiver();
+    let sender = PIPE_SEND.sender();
+    let receiver = PIPE_SEND.receiver();
 
-    spawner.spawn(bit_send(tx, receiver)).unwrap();
-    spawner.spawn(bit_receive_and_decode(rx)).unwrap();
+    let e_nrz = semestralka2::Encoding::Nrz;
+    spawner.spawn(bit_send(tx, receiver, e_nrz)).unwrap();
+    spawner.spawn(bit_receive_and_decode(rx, e_nrz)).unwrap();
 
     info!("starting loop");
     loop {
-        nrz(b"ahoj", &sender).await;
-        nrz(b"hello", &sender).await;
+        msg_encode(b"ahoj", &sender).await;
+        msg_encode(b"hello", &sender).await;
 
         let data = [0x01, 0x02, 0x03, 0x04];
-        nrz(&data, &sender).await;
+        msg_encode(&data, &sender).await;
 
         info!("frame sent");
         embassy_time::Timer::after(Duration::from_secs(1)).await;

2sem_sem2/src/lib.rs

@@ -2,3 +2,20 @@
 
 pub mod receive;
 pub mod send;
+
+#[derive(Copy, Clone, PartialEq)]
+pub enum Encoding {
+    Nrz,
+    Nrzi,
+    Manchester,
+}
+
+pub const LOGIC_ONE_HIGH: bool = true;
+
+pub fn level_for_bit(bit: u8) -> bool {
+    (bit != 0) == LOGIC_ONE_HIGH
+}
+
+pub fn bit_for_level(level: bool) -> u8 {
+    if level == LOGIC_ONE_HIGH { 1 } else { 0 }
+}

2sem_sem2/src/receive.rs

@@ -1,6 +1,8 @@
 use defmt::info;
 use embassy_stm32::exti::ExtiInput;
-use embassy_time::{Duration, Timer};
+use embassy_time::{Ticker, Timer};
+
+use crate::{Encoding, bit_for_level, level_for_bit};
 
 const START: u8 = 0x7E;
 const STOP: u8 = 0x81;
@@ -18,32 +20,99 @@ fn crc8(crc: u8, byte: u8) -> u8 {
     c
 }
 
-async fn sample_byte(pin: &mut ExtiInput<'static>, bit_time: Duration) -> u8 {
+async fn sample_byte(
+    pin: &mut ExtiInput<'static>,
+    encoding: Encoding,
+    ticker: &mut Ticker,
+    last_physical_level: &mut bool,
+    bit_time: embassy_time::Duration,
+) -> u8 {
     let mut byte = 0u8;
     for _ in 0..8 {
-        let bit = if pin.is_high() { 1 } else { 0 };
+        let current_level = pin.is_high();
+        let bit = match encoding {
+            Encoding::Nrz => {
+                let bit = bit_for_level(pin.is_high());
+                ticker.next().await;
+                bit
+            }
+            Encoding::Nrzi => {
+                let bit = if current_level != *last_physical_level {
+                    1
+                } else {
+                    0
+                };
+                *last_physical_level = current_level;
+                ticker.next().await;
+                bit
+            }
+            Encoding::Manchester => {
+                Timer::after(bit_time / 4).await;
+                let first_half = pin.is_high();
+
+                Timer::after(bit_time / 2).await;
+                let second_half = pin.is_high();
+
+                Timer::after(bit_time / 4).await;
+
+                if first_half == level_for_bit(1) && second_half == level_for_bit(0) {
+                    1
+                } else {
+                    0
+                }
+            }
+        };
         byte = (byte << 1) | bit;
-        Timer::after(bit_time).await;
     }
     byte
 }
 
 #[embassy_executor::task]
-pub async fn bit_receive_and_decode(mut pin: ExtiInput<'static>) {
+pub async fn bit_receive_and_decode(mut pin: ExtiInput<'static>, encoding: Encoding) {
     loop {
         pin.wait_for_falling_edge().await;
-
         let t1 = embassy_time::Instant::now();
 
         pin.wait_for_rising_edge().await;
         let bit_time = embassy_time::Instant::now().duration_since(t1);
 
+        // stred data bitu
+        if encoding != Encoding::Manchester {
             Timer::after(bit_time / 2).await;
+        }
+
+        let mut ticker = Ticker::every(bit_time);
+        let mut last_level = level_for_bit(1);
+
         let mut start_byte = 0u8;
         for _ in 0..7 {
-            let bit = if pin.is_high() { 1 } else { 0 };
+            let bit = match encoding {
+                Encoding::Nrz => {
+                    let bit = bit_for_level(pin.is_high());
+                    ticker.next().await;
+                    bit
+                }
+                Encoding::Nrzi => {
+                    let current_level = pin.is_high();
+                    let b = if current_level != last_level { 1 } else { 0 };
+                    last_level = current_level;
+                    ticker.next().await;
+                    b
+                }
+                Encoding::Manchester => {
+                    Timer::after(bit_time / 4).await;
+                    let first_pol = pin.is_high();
+                    Timer::after(bit_time / 2).await;
+                    let second_pol = pin.is_high();
+                    Timer::after(bit_time / 4).await;
+                    if first_pol == level_for_bit(1) && second_pol == level_for_bit(0) {
+                        1
+                    } else {
+                        0
+                    }
+                }
+            };
             start_byte = (start_byte << 1) | bit;
-            Timer::after(bit_time).await;
         }
 
         if start_byte != START {
@@ -52,7 +121,7 @@ pub async fn bit_receive_and_decode(mut pin: ExtiInput<'static>) {
         }
 
         // len
-        let len = sample_byte(&mut pin, bit_time).await;
+        let len = sample_byte(&mut pin, encoding, &mut ticker, &mut last_level, bit_time).await;
         if len as usize > MAX_PAYLOAD {
             info!("bad len {}", len);
             continue;
@@ -61,18 +130,44 @@ pub async fn bit_receive_and_decode(mut pin: ExtiInput<'static>) {
         // payload
         let mut payload = [0u8; MAX_PAYLOAD];
         for i in 0..(len as usize) {
-            payload[i] = sample_byte(&mut pin, bit_time).await;
+            payload[i] =
+                sample_byte(&mut pin, encoding, &mut ticker, &mut last_level, bit_time).await;
         }
 
         // crc
-        let crc_recv = sample_byte(&mut pin, bit_time).await;
+        let crc_recv =
+            sample_byte(&mut pin, encoding, &mut ticker, &mut last_level, bit_time).await;
 
         // parita
-        let parity_recv = if pin.is_high() { 1 } else { 0 };
-        Timer::after(bit_time).await;
+        let parity_recv = match encoding {
+            Encoding::Nrz => {
+                let bit = bit_for_level(pin.is_high());
+                ticker.next().await;
+                bit
+            }
+            Encoding::Nrzi => {
+                let current_p = pin.is_high();
+                let b = if current_p != last_level { 1 } else { 0 };
+                last_level = current_p;
+                ticker.next().await;
+                b
+            }
+            Encoding::Manchester => {
+                Timer::after(bit_time / 4).await;
+                let f = pin.is_high();
+                Timer::after(bit_time / 2).await;
+                let s = pin.is_high();
+                Timer::after(bit_time / 4).await;
+                if f == level_for_bit(1) && s == level_for_bit(0) {
+                    1
+                } else {
+                    0
+                }
+            }
+        };
 
         // stop
-        let stop = sample_byte(&mut pin, bit_time).await;
+        let stop = sample_byte(&mut pin, encoding, &mut ticker, &mut last_level, bit_time).await;
         if stop != STOP {
             info!("bad stop 0x{:02X}", stop);
             continue;

2sem_sem2/src/send.rs

@@ -1,17 +1,23 @@
 // src/send.rs
 
-use embassy_stm32::gpio::Output;
+use embassy_stm32::gpio::{Level, Output};
 use embassy_sync::{
     blocking_mutex::raw::CriticalSectionRawMutex,
     channel::{Receiver, Sender},
 };
 use embassy_time::{Duration, Ticker};
 
+use crate::{level_for_bit, Encoding};
+
 const START: u8 = 0x7E;
 const STOP: u8 = 0x81;
 const BIT_PERIOD: Duration = Duration::from_millis(10);
 
-type Tx = Sender<'static, CriticalSectionRawMutex, u8, 128>;
+pub type Tx = Sender<'static, CriticalSectionRawMutex, u8, 128>;
+
+fn set_level(pin: &mut Output<'static>, is_high: bool) {
+    pin.set_level(if is_high { Level::High } else { Level::Low });
+}
 
 async fn send_byte(byte: u8, tx: &Tx) {
     for i in (0..8).rev() {
@@ -20,7 +26,7 @@ async fn send_byte(byte: u8, tx: &Tx) {
 }
 
 /// [START] [LEN] [PAYLOAD ...] [CRC] [P] [STOP]
-pub async fn nrz(payload: &[u8], tx: &Tx) {
+pub async fn msg_encode(payload: &[u8], tx: &Tx) {
     // start
     send_byte(START, tx).await;
 
@@ -66,16 +72,48 @@ fn crc8(crc: u8, byte: u8) -> u8 {
 pub async fn bit_send(
     mut pin: Output<'static>,
     rx: Receiver<'static, CriticalSectionRawMutex, u8, 128>,
+    encoding: Encoding,
 ) {
-    let mut ticker = Ticker::every(BIT_PERIOD);
+    let mut ticker = Ticker::every(BIT_PERIOD / 2);
+    let mut is_high = level_for_bit(1);
+    set_level(&mut pin, is_high);
+
     loop {
         let bit = rx.receive().await;
+        match encoding {
+            Encoding::Nrz => {
+                is_high = level_for_bit(bit);
+                set_level(&mut pin, is_high);
+                ticker.next().await;
+            }
+            // toggle, ak sme v 1, inac sa nedeje nic
+            Encoding::Nrzi => {
                 if bit == 1 {
+                    is_high = !is_high;
+                    if is_high {
                         pin.set_high();
                     } else {
                         pin.set_low();
                     }
-        // bitrate
+                }
                 ticker.next().await;
             }
+            // manchester xor tabulka
+            Encoding::Manchester => {
+                if bit == 1 {
+                    // high -> low
+                    set_level(&mut pin, level_for_bit(1));
+                    ticker.next().await;
+                    set_level(&mut pin, level_for_bit(0));
+                    ticker.next().await;
+                } else {
+                    // low -> high
+                    set_level(&mut pin, level_for_bit(0));
+                    ticker.next().await;
+                    set_level(&mut pin, level_for_bit(1));
+                    ticker.next().await;
+                }
+            }
+        };
+    }
 }