From 22b3b2307d7ca25dd5be4293d2e1fe03a8d70a43 Mon Sep 17 00:00:00 2001
From: Priec <filippriec@gmail.com>
Date: Sun, 17 May 2026 22:47:31 +0200
Subject: [PATCH] redesign of sent data

---
 2sem_sem2/src/bin/main.rs |  5 ++-
 2sem_sem2/src/send.rs     | 76 ++++++++++++++++++++++-----------------
 2 files changed, 46 insertions(+), 35 deletions(-)

diff --git a/2sem_sem2/src/bin/main.rs b/2sem_sem2/src/bin/main.rs
index 2560b0b..7940917 100644
--- a/2sem_sem2/src/bin/main.rs
+++ b/2sem_sem2/src/bin/main.rs
@@ -37,7 +37,7 @@ async fn main(spawner: Spawner) {
 
     spawner.spawn(bit_send(tx, sender_receiver)).unwrap();
     spawner.spawn(bit_receive_and_decode(rx)).unwrap();
-    spawner.spawn(bit_decode(receiver_reader)).unwrap();
+    // spawner.spawn(bit_decode(receiver_reader)).unwrap();
 
     info!("starting echo");
     let mut v: Vec<u8, 38, u8> = Vec::new();
@@ -51,7 +51,6 @@ async fn main(spawner: Spawner) {
         info!("enkodovane, posielame do pipy...");
         nrz(&v, &sender).await;
 
-        let _ = Timer::after(Duration::from_millis(1000));
-        embassy_time::block_for(Duration::from_millis(1000));
+        Timer::after(Duration::from_millis(1000)).await;
     }
 }
diff --git a/2sem_sem2/src/send.rs b/2sem_sem2/src/send.rs
index 8df3687..ebdf57c 100644
--- a/2sem_sem2/src/send.rs
+++ b/2sem_sem2/src/send.rs
@@ -10,58 +10,70 @@ use embassy_sync::{
 use embassy_time::{Duration, Ticker};
 use heapless::Vec;
 
-static SEND_ALLOWED: AtomicBool = AtomicBool::new(true);
+const START: u8 = 0x7E;
+const STOP: u8 = 0x81;
+const BIT_PERIOD: Duration = Duration::from_millis(10);
 
-pub fn encode(word: &str, v: &mut Vec<u8, 38, u8>) {
-    v.clear();
-    for byte in word.bytes() {
-        for bit in 0..8 {
-            let bit_value = (byte >> (7 - bit)) & 1;
-            if v.push(bit_value).is_err() {
-                info!("we panick boyz");
-                return;
-            }
+type Tx = Sender<'static, CriticalSectionRawMutex, u8, 128>;
+
+fn crc8(data: &[u8]) -> u8 {
+    let mut crc: u8 = 0;
+    for &b in data {
+        crc ^= b;
+        for _ in 0..8 {
+            let mask = if (crc & 0x80) != 0 { 0x07 } else { 0 };
+            crc = (crc << 1) ^ mask;
         }
     }
+    crc
+}
+
+async fn send_byte(byte: u8, tx: &Tx) {
+    for i in (0..8).rev() {
+        tx.send((byte >> i) & 1).await;
+    }
 }
 
-pub async fn nrz(
-    enkodovany: &Vec<u8, 38, u8>,
-    sender: &Sender<'_, CriticalSectionRawMutex, u8, 64>,
-) {
-    if !SEND_ALLOWED.load(Ordering::Relaxed) {
-        return;
-    }
-    let sync_hod: u8 = 0xAA;
-    let start_bits: u8 = 0xAB;
-    let sequence = [sync_hod, start_bits];
+/// [START] [LEN] [PAYLOAD ...] [CRC] [P] [STOP]
+pub async fn nrz(payload: &[u8], tx: &Tx) {
+    // start
+    send_byte(START, tx).await;
 
-    for byte in sequence {
-        for i in (0..8).rev() {
-            sender.send((byte >> i) & 1).await;
-        }
+    // len
+    let len = payload.len() as u8;
+    send_byte(len, tx).await;
+    for &b in payload {
+        send_byte(b, tx).await;
     }
 
-    for &bit in enkodovany {
-        sender.send(bit).await;
+    let mut buf: Vec<u8, 64> = Vec::new();
+    let _ = buf.push(len);
+    for &b in payload {
+        let _ = buf.push(b);
     }
+    let crc = crc8(&buf);
+    send_byte(crc, tx).await;
 
-    for i in (0..8).rev() {
-        sender.send((sync_hod >> i) & 1).await;
+    let mut ones = len.count_ones() + crc.count_ones();
+    for &b in payload {
+        ones += b.count_ones();
     }
+    tx.send((ones as u8) & 1).await;
+
+    send_byte(STOP, tx).await;
 
     // idle
-    sender.send(1).await;
+    tx.send(1).await;
 }
 
 #[embassy_executor::task]
 pub async fn bit_send(
     mut pin: Output<'static>,
-    receiver: Receiver<'static, CriticalSectionRawMutex, u8, 64>,
+    rx: Receiver<'static, CriticalSectionRawMutex, u8, 64>,
 ) {
-    let mut ticker = Ticker::every(Duration::from_millis(10));
+    let mut ticker = Ticker::every(BIT_PERIOD);
     loop {
-        let bit = receiver.receive().await;
+        let bit = rx.receive().await;
         if bit == 1 {
             pin.set_high();
         } else {