(Add) ntrip_client.py GGA sentence generation and sending

src/fc_network_module/fc_network_module/ntrip_client.py

@@ -8,11 +8,65 @@ from rclpy.node import Node
 from rclpy.qos import QoSProfile, HistoryPolicy, ReliabilityPolicy, DurabilityPolicy
 from mavros_msgs.msg import RTCM
 
+# TODO: ROS_DOMAIN_ID 要補一下
+
+class GGA_stream():
+
+    @classmethod
+    def nmea_checksum(cls, body: str) -> str:
+        """body 不含 '$' 與 '*checksum'，例如 'GPGGA,123519,...'"""
+        value = 0
+        for ch in body:
+            value ^= ord(ch)
+        return f"{value:02X}"
+
+    @classmethod
+    def decimal_to_nmea_dm(cls, deg: float, *, is_latitude: bool) -> tuple[str, str]:
+        """十進位度 → NMEA 的 (d)dmm.mmmm 與半球字元。"""
+        if is_latitude:
+            hemi = "N" if deg >= 0 else "S"
+            deg_width = 2
+        else:
+            hemi = "E" if deg >= 0 else "W"
+            deg_width = 3
+        deg = abs(deg)
+        d = int(deg)
+        m = (deg - d) * 60.0
+        return f"{d:0{deg_width}d}{m:07.4f}", hemi
+
+    @classmethod
+    def build_gga_sentence(cls, lat_deg: float, lon_deg: float, alt_m: float = 100.0) -> bytes:
+        """
+        組一筆 $GPGGA 句子（含 checksum) 回傳 bytes 可直接 sock.sendall。
+
+        lat_deg / lon_deg : 十進位經緯度(北、東為正)。
+        測試時請改成 mount 服務範圍內的近似位置；正式使用應來自 GNSS 真實定位。
+        """
+        utc = time.gmtime()
+        t_str = f"{utc.tm_hour:02d}{utc.tm_min:02d}{utc.tm_sec:02d}.00"
+
+        lat_dm, ns = cls.decimal_to_nmea_dm(lat_deg, is_latitude=True)
+        lon_dm, ew = cls.decimal_to_nmea_dm(lon_deg, is_latitude=False)
+
+        # quality=1（GPS fix）、8 顆星、HDOP=1.0 僅供測試示意
+        body = (
+            f"GPGGA,{t_str},{lat_dm},{ns},{lon_dm},{ew},"
+            f"1,08,1.0,{alt_m:.1f},M,0.0,M,,"
+        )
+        sentence = f"${body}*{cls.nmea_checksum(body)}\r\n"
+        return sentence.encode("ascii")
+
+    @classmethod
+    def send_gga(cls, sock: socket.socket, lat_deg: float, lon_deg: float, alt_m: float = 100.0) -> str:
+        """送出 GGA，回傳可讀句子供列印。"""
+        payload = cls.build_gga_sentence(lat_deg, lon_deg, alt_m)
+        sock.sendall(payload)
+        return payload.decode("ascii").strip()
 
 class NtripClientNode(Node):
-    """連線 NTRIP caster，接收 RTCM3 資料流並發布至 ROS2 topic。"""
+    """連線 NTRIP caster, 接收 RTCM3 資料流並發布至 ROS2 topic """
 
-    RECONNECT_BASE_SEC = 2.0
+    RECONNECT_BASE_SEC = 10.0
     RECONNECT_MAX_SEC = 60.0
 
     def __init__(self):
@@ -21,9 +75,15 @@ class NtripClientNode(Node):
         self.declare_parameter('host', 'rtk2go.com')
         self.declare_parameter('port', 2101)
         self.declare_parameter('mountpoint', '')
-        self.declare_parameter('username', '')
+        self.declare_parameter('username', 'template@mail.com')
         self.declare_parameter('password', '')
 
+        self.declare_parameter('gga_on', False)
+        self.declare_parameter('gga_lat', None)
+        self.declare_parameter('gga_lon', None)
+        self.declare_parameter('gga_alt_m', 100)
+        self.declare_parameter('gga_interval_sec', 300)
+
         rtcm_qos = QoSProfile(
             history=HistoryPolicy.KEEP_LAST,
             depth=1,
@@ -43,28 +103,36 @@ class NtripClientNode(Node):
     def _receive_loop(self):
         backoff = self.RECONNECT_BASE_SEC
 
-        while self._running:
-            host = self.get_parameter('host').value
-            port = self.get_parameter('port').value
-            mount = self.get_parameter('mountpoint').value
-            user = self.get_parameter('username').value
-            pwd = self.get_parameter('password').value
+        host = self.get_parameter('host').value
+        port = self.get_parameter('port').value
+        mountpoint = self.get_parameter('mountpoint').value
+        user = self.get_parameter('username').value
+        pwd = self.get_parameter('password').value
 
-            if not mount:
-                self.get_logger().error('mountpoint 參數未設定，等待重試...')
-                time.sleep(backoff)
-                continue
+        if not mountpoint:
+            self.get_logger().error('mountpoint 參數未設定...')
+            return
+
+        while self._running:
 
             sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             sock.settimeout(10)
 
+            self.gga_lat = self.get_parameter('gga_lat').value
+            self.gga_lon = self.get_parameter('gga_lon').value
+            self.gga_alt_m = self.get_parameter('gga_alt_m').value
+            self.gga_interval_sec = self.get_parameter('gga_interval_sec').value
+            self.gga_on = self.get_parameter('gga_on').value
+            self.gga_on = self.gga_lat is not None and self.gga_lon is not None and self.gga_on
+
+
             try:
-                self.get_logger().info(f'正在連線 {host}:{port}/{mount} ...')
+                self.get_logger().info(f'正在連線 {host}:{port}/{mountpoint} ...')
                 sock.connect((host, port))
 
                 auth = base64.b64encode(f'{user}:{pwd}'.encode()).decode()
                 request = (
-                    f'GET /{mount} HTTP/1.0\r\n'
+                    f'GET /{mountpoint} HTTP/1.0\r\n'
                     f'User-Agent: NTRIP PythonClient\r\n'
                     f'Authorization: Basic {auth}\r\n'
                     f'Connection: close\r\n\r\n'
@@ -78,7 +146,9 @@ class NtripClientNode(Node):
                     )
                     raise ConnectionError('handshake failed')
 
-                self.get_logger().info(f'已連接至 {mount}，開始接收 RTCM 資料流')
+                self.get_logger().info(f'已成功連接至 {mountpoint}')
+
+
                 backoff = self.RECONNECT_BASE_SEC
 
                 self._read_stream(sock)
@@ -93,14 +163,21 @@ class NtripClientNode(Node):
 
     def _read_stream(self, sock: socket.socket):
         buf = b''
+        last_gga_time = 0.0
 
         while self._running:
+            now = time.time()
+            if self.gga_on and (now - last_gga_time >= self.gga_interval_sec):
+                line = GGA_stream.send_gga(sock, self.gga_lat, self.gga_lon, self.gga_alt_m)
+                self.get_logger().info(f"[GGA] {line}")
+                last_gga_time = now
+
             try:
                 chunk = sock.recv(4096)
             except socket.timeout:
                 continue
             if not chunk:
-                break
+                raise ConnectionError("stream ended. Empty Chunk")
             buf += chunk
 
             while len(buf) >= 6: