feat(protocol): add packet protocol

client/src/protocol_parser.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+"""
+FR-1.4 Data Transmission Protocol Parser (v1)
+12-byte binary packet: [0xAA][TYPE=0x02][LEN=8][TIMESTAMP(4)][RMS_DB(2)][FREQ_HZ(2)][CRC8(1)]
+"""
+
+import struct
+from typing import Optional, NamedTuple
+from dataclasses import dataclass
+
+
+class AudioMetrics(NamedTuple):
+    """Parsed audio metrics packet"""
+    timestamp_ms: int
+    rms_db: float
+    freq_hz: int
+    valid: bool = True
+
+
+@dataclass
+class ProtocolStats:
+    """Protocol statistics"""
+    packets_received: int = 0
+    crc_errors: int = 0
+    length_errors: int = 0
+    range_errors: int = 0
+
+
+class ProtocolParser:
+    """
+    Stream parser for FR-1.4 protocol with automatic resynchronization.
+    """
+
+    SOF = 0xAA
+    TYPE_AUDIO_V1 = 0x02
+    PAYLOAD_LEN = 0x08
+    PACKET_SIZE = 12
+
+    def __init__(self):
+        self.buffer = bytearray()
+        self.stats = ProtocolStats()
+
+    @staticmethod
+    def _crc8_atm(data: bytes) -> int:
+        """CRC-8/ATM: poly=0x07, init=0x00, refin=false, refout=false, xorout=0x00"""
+        crc = 0x00
+        for byte in data:
+            crc ^= byte
+            for _ in range(8):
+                if crc & 0x80:
+                    crc = ((crc << 1) ^ 0x07) & 0xFF
+                else:
+                    crc = (crc << 1) & 0xFF
+        return crc
+
+    def feed(self, data: bytes) -> list[AudioMetrics]:
+        """
+        Feed incoming bytes, return list of parsed packets.
+
+        Args:
+            data: Raw bytes from serial port
+
+        Returns:
+            List of successfully parsed AudioMetrics
+        """
+        self.buffer.extend(data)
+        packets = []
+
+        while len(self.buffer) >= self.PACKET_SIZE:
+            # Find SOF
+            sof_idx = self.buffer.find(self.SOF)
+            if sof_idx == -1:
+                # No SOF found, discard all but last byte
+                self.buffer = self.buffer[-1:]
+                break
+
+            # Discard bytes before SOF
+            if sof_idx > 0:
+                self.buffer = self.buffer[sof_idx:]
+
+            # Need at least 3 bytes for SOF + TYPE + LEN
+            if len(self.buffer) < 3:
+                break
+
+            packet_type = self.buffer[1]
+            payload_len = self.buffer[2]
+
+            # Validate TYPE and LEN
+            if packet_type != self.TYPE_AUDIO_V1 or payload_len != self.PAYLOAD_LEN:
+                self.stats.length_errors += 1
+                self.buffer.pop(0)  # Remove false SOF, retry
+                continue
+
+            # Full packet size = SOF(1) + TYPE(1) + LEN(1) + PAYLOAD(8) + CRC(1) = 12
+            total_len = 3 + payload_len + 1
+            if len(self.buffer) < total_len:
+                break  # Wait for more data
+
+            packet = bytes(self.buffer[:total_len])
+
+            # Verify CRC (over bytes 1..10: TYPE, LEN, payload)
+            crc_data = packet[1:11]
+            expected_crc = packet[11]
+            calculated_crc = self._crc8_atm(crc_data)
+
+            if calculated_crc != expected_crc:
+                self.stats.crc_errors += 1
+                self.buffer.pop(0)  # Remove bad packet, retry
+                continue
+
+            # Parse payload (little-endian)
+            timestamp_ms, rms_db_x10, freq_hz = struct.unpack_from('<IhH', packet, 3)
+
+            # Convert and validate ranges
+            rms_db = rms_db_x10 / 10.0
+            valid = True
+            if not (-40.0 <= rms_db <= 80.0) or not (100 <= freq_hz <= 8000):
+                self.stats.range_errors += 1
+                valid = False
+
+            self.stats.packets_received += 1
+            packets.append(AudioMetrics(
+                timestamp_ms=timestamp_ms,
+                rms_db=rms_db,
+                freq_hz=freq_hz,
+                valid=valid
+            ))
+
+            # Remove processed packet
+            self.buffer = self.buffer[total_len:]
+
+        return packets
+
+    def get_stats(self) -> ProtocolStats:
+        """Get current statistics"""
+        return self.stats

client/src/receiver.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+"""
+Example client for FR-1.4 protocol
+"""
+import serial
+import time
+from protocol_parser import ProtocolParser
+
+
+def main():
+    SERIAL_PORT = "/dev/ttyACM0"
+    BAUDRATE = 115200
+
+    parser = ProtocolParser()
+
+    try:
+        with serial.Serial(SERIAL_PORT, BAUDRATE, timeout=1) as ser:
+            print(f"Connected to {SERIAL_PORT}")
+
+            while True:
+                # Read available data
+                if ser.in_waiting > 0:
+                    data = ser.read(ser.in_waiting)
+
+                    # Parse packets
+                    packets = parser.feed(data)
+                    for pkt in packets:
+                        if pkt.valid:
+                            print(
+                                f"[{pkt.timestamp_ms:010d}] "
+                                f"RMS: {pkt.rms_db:+6.1f} dB  "
+                                f"Freq: {pkt.freq_hz:4d} Hz"
+                            )
+                        else:
+                            print(f"[WARN] Invalid packet: {pkt}")
+
+                    # Show stats every 100 packets
+                    stats = parser.get_stats()
+                    if stats.packets_received % 100 == 0 and stats.packets_received > 0:
+                        print(
+                            f"Stats: RX={stats.packets_received} "
+                            f"CRC_err={stats.crc_errors} "
+                            f"LEN_err={stats.length_errors} "
+                            f"Range_err={stats.range_errors}"
+                        )
+
+                time.sleep(0.01)
+
+    except KeyboardInterrupt:
+        print("\nExiting...")
+    except serial.SerialException as e:
+        print(f"Error: {e}")
+
+
+if __name__ == "__main__":
+    main()

client/src/reveier.py

@@ -1,43 +0,0 @@
-#!/usr/bin/env python3
-import sys
-import time
-
-import serial
-
-# Настройки порта
-SERIAL_PORT = "/dev/ttyACM0"
-BAUD_RATE = 115200
-
-
-def read_serial_data():
-    try:
-        # Открытие порта. Timeout позволяет прерывать блокирующее чтение.
-        ser = serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=1)
-        print(f"Connected to {SERIAL_PORT}")
-
-        while True:
-            if ser.in_waiting > 0:
-                # Чтение строки, декодирование и удаление пробелов
-                line = ser.readline().decode("utf-8", errors="replace").strip()
-                if line:
-                    print(f"[RX]: {line}")
-            else:
-                # Небольшая пауза, чтобы не грузить CPU ПК
-                time.sleep(0.01)
-
-    except serial.SerialException as e:
-        print(f"Error opening serial port: {e}")
-        print(
-            "Hint: Check if /dev/ttyACM0 exists and you have permissions (group uucp)."
-        )
-    except KeyboardInterrupt:
-        print("\nExiting...")
-    except:
-        print("\nAn error occure!")
-    finally:
-        if "ser" in locals() and ser.is_open:
-            ser.close()
-
-
-if __name__ == "__main__":
-    read_serial_data()

client/src/test_usb.py

@@ -1,19 +0,0 @@
-#!/usr/bin/env python3
-import serial
-import time
-
-port = serial.Serial("/dev/ttyACM0", 115200, timeout=1)
-print(f"Connected to {port.name}")
-
-port.write(b"test\n")
-time.sleep(0.1)
-
-# Читаем 5 секунд
-start = time.time()
-while time.time() - start < 5:
-    if port.in_waiting:
-        data = port.read(port.in_waiting)
-        print(f"RX: {data.decode('utf-8', errors='replace')}", end="")
-    time.sleep(0.1)
-
-port.close()

firmware/App/Inc/protocol.h

@@ -0,0 +1,40 @@
+#ifndef PROTOCOL_H
+#define PROTOCOL_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+// Protocol Constants
+#define PROTOCOL_SOF 0xAA
+#define PACKET_TYPE_AUDIO 0x02
+#define PACKET_LEN_V1 0x08  // Payload length (excluding SOF, TYPE, LEN, CRC)
+#define PACKET_TOTAL_SIZE 12
+
+// CRC8-ATM Constants
+#define CRC8_POLY 0x07
+#define CRC8_INIT 0x00
+
+/**
+ * @brief  Calculates CRC-8/ATM over the data buffer.
+ *         Polynomial: x^8 + x^2 + x + 1 (0x07)
+ *         Init: 0x00, RefIn: false, RefOut: false, XorOut: 0x00
+ * @param  data Pointer to data buffer
+ * @param  len  Length of data
+ * @return Calculated CRC8
+ */
+uint8_t crc8_atm(const uint8_t *data, size_t len);
+
+/**
+ * @brief Encodes the audio metric packet into the wire format.
+ * @param buf Output buffer (must be at least 12 bytes)
+ * @param timestamp_ms Timestamp in milliseconds
+ * @param rms_dbfs RMS value in dBFS (float)
+ * @param freq_hz Peak frequency in Hz (float)
+ */
+void protocol_pack_v1(
+    uint8_t *buf,
+    uint32_t timestamp_ms,
+    float rms_dbfs,
+    float freq_hz);
+
+#endif  // PROTOCOL_H

firmware/App/Src/main.c

@@ -3,6 +3,7 @@
 #include "FreeRTOS.h"
 #include "audio_adc.h"
 #include "audio_processor.h"  // НОВОЕ
+#include "protocol.h"
 #include "queue.h"
 #include "stm32f1xx.h"
 #include "task.h"
@@ -19,13 +20,12 @@ void vApplicationStackOverflowHook(TaskHandle_t xTask, char *pcTaskName) {
 
 // === Структуры данных ===
 
-// НОВОЕ: пакет с результатами FFT
 typedef struct {
     float rms_dbfs;
     float peak_hz;
     float peak_mag;
     uint8_t clipped;
-    uint32_t buffer_num;
+    uint32_t timestamp_ms;
 } audio_metrics_packet_t;
 
 static QueueHandle_t audio_metrics_queue = NULL;
@@ -119,7 +119,8 @@ void audio_process_task(void *param) {
                     .peak_hz = metrics.peak_hz,
                     .peak_mag = metrics.peak_mag,
                     .clipped = metrics.clipped,
-                    .buffer_num = buffer_counter};
+                    .timestamp_ms = xTaskGetTickCount(),
+                };
                 xQueueSend(audio_metrics_queue, &packet, 0);
             }
         }
@@ -128,83 +129,37 @@ void audio_process_task(void *param) {
 
 void cdc_task(void *param) {
     (void)param;
-
+    // Buffer for the FR-1.4 packet (12 bytes)
-    char tx_buffer[256];
+    uint8_t tx_buffer[PACKET_TOTAL_SIZE];
-    uint32_t heartbeat_counter = 0;
 
     while (1) {
-        heartbeat_counter++;
+        // Check if USB is connected
+        if (tud_cdc_connected()) {
+            audio_metrics_packet_t packet;
 
-        // Heartbeat каждые 100 циклов
+            // Wait for data from DSP task
-        if (heartbeat_counter % 100 == 0 && tud_cdc_connected()) {
+            if (xQueueReceive(
-            uint32_t current_buffer_count = audio_adc_get_buffer_count();
+                    audio_metrics_queue,
+                    &packet,
+                    pdMS_TO_TICKS(10)) == pdPASS) {
+                // Pack data according to FR-1.4 spec
+                protocol_pack_v1(
+                    tx_buffer,
+                    packet.timestamp_ms,
+                    packet.rms_dbfs,
+                    packet.peak_hz);
 
-            int len = snprintf(
+                // Write to USB CDC
-                tx_buffer,
+                // Check available space just in case
-                sizeof(tx_buffer),
+                if (tud_cdc_write_available() >= sizeof(tx_buffer)) {
-                "HB:%lu Q:%u BC:%lu\r\n",
+                    tud_cdc_write(tx_buffer, sizeof(tx_buffer));
-                heartbeat_counter,
+                    tud_cdc_write_flush();
-                (unsigned)uxQueueMessagesWaiting(audio_metrics_queue),
+                }
-                current_buffer_count);
-
-            if (len > 0 && tud_cdc_write_available() >= (uint32_t)len) {
-                tud_cdc_write(tx_buffer, (uint32_t)len);
-                tud_cdc_write_flush();
-            }
-        }
-
-        // Метрики FFT
-        audio_metrics_packet_t packet;
-        if (xQueueReceive(audio_metrics_queue, &packet, pdMS_TO_TICKS(10)) ==
-            pdPASS) {
-            // fixed-point:
-            // RMS: dBFS * 10 (один знак после запятой)
-            int32_t rms_x10 = (int32_t)(packet.rms_dbfs * 10.0f);
-            int32_t rms_int = rms_x10 / 10;
-            int32_t rms_frac = rms_x10 % 10;
-            if (rms_frac < 0) rms_frac = -rms_frac;
-
-            // Freq: Hz * 10 (один знак после запятой)
-            int32_t freq_x10 = (int32_t)(packet.peak_hz * 10.0f);
-            int32_t freq_int = freq_x10 / 10;
-            int32_t freq_frac = freq_x10 % 10;
-            if (freq_frac < 0) freq_frac = -freq_frac;
-
-            // Mag: *1000 (три знака после запятой)
-            int32_t mag_x1000 = (int32_t)(packet.peak_mag * 1000.0f);
-            int32_t mag_int = mag_x1000 / 1000;
-            int32_t mag_frac = mag_x1000 % 1000;
-            if (mag_frac < 0) mag_frac = -mag_frac;
-
-            int len = snprintf(
-                tx_buffer,
-                sizeof(tx_buffer),
-                "Buf:%lu RMS:%ld.%01ld dBFS Freq:%ld.%01ld Hz Mag:%ld.%03ld "
-                "Clip:%u\r\n",
-                packet.buffer_num,
-                (long)rms_int,
-                (long)rms_frac,
-                (long)freq_int,
-                (long)freq_frac,
-                (long)mag_int,
-                (long)mag_frac,
-                (unsigned)packet.clipped);
-
-            if (len > 0 && tud_cdc_connected() &&
-                tud_cdc_write_available() >= (uint32_t)len) {
-                tud_cdc_write(tx_buffer, (uint32_t)len);
-                tud_cdc_write_flush();
-            }
-        }
-
-        // Echo
-        if (tud_cdc_available()) {
-            uint8_t buf[64];
-            uint32_t count = tud_cdc_read(buf, sizeof(buf));
-            if (tud_cdc_connected() && count > 0) {
-                tud_cdc_write(buf, count);
-                tud_cdc_write_flush();
             }
+        } else {
+            // Flush queue if USB not connected to prevent stalling DSP task
+            // or just sleep longer.
+            vTaskDelay(pdMS_TO_TICKS(100));
         }
     }
 }

firmware/App/Src/protocol.c

@@ -0,0 +1,51 @@
+#include "protocol.h"
+#include <math.h>
+
+uint8_t crc8_atm(const uint8_t *data, size_t len) {
+    uint8_t crc = CRC8_INIT;
+    for (size_t i = 0; i < len; i++) {
+        crc ^= data[i];
+        for (uint8_t j = 0; j < 8; j++) {
+            if (crc & 0x80) {
+                crc = (crc << 1) ^ CRC8_POLY;
+            } else {
+                crc <<= 1;
+            }
+        }
+    }
+    return crc;
+}
+
+void protocol_pack_v1(
+    uint8_t *buf,
+    uint32_t timestamp_ms,
+    float rms_dbfs,
+    float freq_hz) {
+    // Header
+    buf[0] = PROTOCOL_SOF;
+    buf[1] = PACKET_TYPE_AUDIO;
+    buf[2] = PACKET_LEN_V1;
+
+    // Payload: Timestamp (4 bytes, Little Endian)
+    buf[3] = (uint8_t)(timestamp_ms & 0xFF);
+    buf[4] = (uint8_t)((timestamp_ms >> 8) & 0xFF);
+    buf[5] = (uint8_t)((timestamp_ms >> 16) & 0xFF);
+    buf[6] = (uint8_t)((timestamp_ms >> 24) & 0xFF);
+
+    // Payload: RMS_DB (2 bytes, Little Endian, x10, int16)
+    // Range check implicit by int16 cast, but clamping is safer
+    // Spec: -40..80 dB -> -400..800
+    // Note: Since DSP returns dBFS (negative), we just send it as is.
+    // E.g. -60.5 dB -> -605.
+    int16_t rms_fixed = (int16_t)(rms_dbfs * 10.0f);
+    buf[7] = (uint8_t)(rms_fixed & 0xFF);
+    buf[8] = (uint8_t)((rms_fixed >> 8) & 0xFF);
+
+    // Payload: FREQ_HZ (2 bytes, Little Endian, uint16)
+    uint16_t freq_fixed = (uint16_t)freq_hz;
+    buf[9] = (uint8_t)(freq_fixed & 0xFF);
+    buf[10] = (uint8_t)((freq_fixed >> 8) & 0xFF);
+
+    // CRC8 (Calculated over bytes 1..10: TYPE, LEN, Payload)
+    buf[11] = crc8_atm(&buf[1], 10);
+}

firmware/Makefile

@@ -6,6 +6,7 @@ C_SOURCES =  \
 App/Src/main.c \
 App/Src/audio_adc.c \
 App/Src/audio_processor.c \
+App/Src/protocol.c \
 App/Src/usb_descriptors.c \
 App/Src/system_stm32f1xx.c \