implement review comments

src/anchor_pkg/anchor_pkg/anchor_node.py

@@ -14,12 +14,11 @@ from .connector import (
     NoValidDeviceException,
     NoWorkingDeviceException,
 )
-from .convert import string_to_viccan
+from .convert import string_to_viccan, viccan_to_string
-import sys
 import threading
 
-from std_msgs.msg import String, Header
 from astra_msgs.msg import VicCAN
+from std_msgs.msg import String
 
 
 class Anchor(Node):
@@ -33,12 +32,16 @@ class Anchor(Node):
         - VicCAN messages for Arm node
     * /anchor/from_vic/bio
         - VicCAN messages for Bio node
+    * /anchor/to_vic/debug
+        - A string copy of the messages published to ./relay are published here
 
     Subscribers:
     * /anchor/from_vic/mock_mcu
         - For testing without an actual MCU, publish strings here as if they came from an MCU
     * /anchor/to_vic/relay
         - Core, Arm, and Bio publish VicCAN messages to this topic to send to the MCU
+    * /anchor/to_vic/relay_string
+        - Send raw strings to connectors. Does not work for connectors that require conversion (like CANConnector)
     """
 
     connector: Connector
@@ -59,31 +62,96 @@ class Anchor(Node):
             ),
         )
 
+        self.declare_parameter(
+            "can_override",
+            "",
+            ParameterDescriptor(
+                name="can_override",
+                description="Overrides which CAN channel will be used. Defaults to ''.",
+                type=ParameterType.PARAMETER_STRING,
+                additional_constraints="Must be a valid CAN network that shows up in `ip link show`.",
+            ),
+        )
+
+        # ROS2 Topic Setup
+
+        # Publishers
+        self.fromvic_debug_pub_ = self.create_publisher(  # only used by serial
+            String,
+            "/anchor/from_vic/debug",
+            20,
+        )
+        self.fromvic_core_pub_ = self.create_publisher(
+            VicCAN,
+            "/anchor/from_vic/core",
+            20,
+        )
+        self.fromvic_arm_pub_ = self.create_publisher(
+            VicCAN,
+            "/anchor/from_vic/arm",
+            20,
+        )
+        self.fromvic_bio_pub_ = self.create_publisher(
+            VicCAN,
+            "/anchor/from_vic/bio",
+            20,
+        )
+        # Debug publisher
+        self.tovic_debug_pub_ = self.create_publisher(
+            VicCAN,
+            "/anchor/to_vic/debug",
+            20,
+        )
+
+        # Subscribers
+        self.tovic_sub_ = self.create_subscription(
+            VicCAN,
+            "/anchor/to_vic/relay",
+            self.write_connector,
+            20,
+        )
+        self.mock_mcu_sub_ = self.create_subscription(
+            String,
+            "/anchor/from_vic/mock_mcu",
+            self.on_mock_fromvic,
+            20,
+        )
+        self.tovic_string_sub_ = self.create_subscription(
+            String,
+            "/anchor/to_vic/relay_string",
+            self.connector.write_raw,
+            20,
+        )
+
         # Determine which connector to use. Options are Mock, Serial, and CAN
         connector_select = (
             self.get_parameter("connector").get_parameter_value().string_value
         )
-
+        can_override = (
+            self.get_parameter("can_override").get_parameter_value().string_value
+        )
         match connector_select:
             case "serial":
                 logger.info("using serial connector")
-                self.connector = SerialConnector(self.get_logger())
+                self.connector = SerialConnector(logger, self.get_clock())
             case "can":
                 logger.info("using CAN connector")
-                self.connector = CANConnector(self.get_logger())
+                self.connector = CANConnector(logger, self.get_clock(), can_override)
             case "mock":
                 logger.info("using mock connector")
-                self.connector = MockConnector(self.get_logger())
+                self.connector = MockConnector(logger, self.get_clock())
             case "auto":
                 logger.info("automatically determining connector")
                 try:
                     logger.info("trying CAN connector")
-                    self.connector = CANConnector(self.get_logger())
+                    self.connector = CANConnector(
+                        logger, self.get_clock(), can_override
+                    )
                 except (NoValidDeviceException, NoWorkingDeviceException, TypeError):
                     logger.info("CAN connector failed, trying serial connector")
-                    self.connector = SerialConnector(self.get_logger())
+                    self.connector = SerialConnector(logger, self.get_clock())
             case _:
-                self.get_logger().fatal(
+                logger.fatal(
                     f"invalid value for connector parameter: {connector_select}"
                 )
                 exit(1)
@@ -91,46 +159,26 @@ class Anchor(Node):
         # Close devices on exit
         atexit.register(self.cleanup)
 
-        # ROS2 Topic Setup
-
-        # Publishers
-        self.fromvic_debug_pub_ = self.create_publisher(
-            String, "/anchor/from_vic/debug", 20
-        )
-        self.fromvic_core_pub_ = self.create_publisher(
-            VicCAN, "/anchor/from_vic/core", 20
-        )
-        self.fromvic_arm_pub_ = self.create_publisher(
-            VicCAN, "/anchor/from_vic/arm", 20
-        )
-        self.fromvic_bio_pub_ = self.create_publisher(
-            VicCAN, "/anchor/from_vic/bio", 20
-        )
-
-        # Subscribers
-        self.tovic_sub_ = self.create_subscription(
-            VicCAN, "/anchor/to_vic/relay", self.connector.write, 20
-        )
-        self.mock_mcu_sub_ = self.create_subscription(
-            String, "/anchor/from_vic/mock_mcu", self.on_mock_fromvic, 20
-        )
-
     def cleanup(self):
         self.connector.cleanup()
 
-    def read_MCU(self):
+    def read_connector(self):
-        """Check the USB serial port for new data from the MCU, and publish string to appropriate topics"""
+        """Check the connector for new data from the MCU, and publish string to appropriate topics"""
-        output = self.connector.read()
+        viccan, raw = self.connector.read()
 
-        if not output:
+        if raw:
-            return
+            self.fromvic_debug_pub_.publish(String(data=raw))
 
-        self.relay_fromvic(output)
+        if viccan:
+            self.relay_fromvic(viccan)
+
+    def write_connector(self, msg: VicCAN):
+        """Write to the connector and send a copy to /anchor/to_vic/debug"""
+        self.connector.write(msg)
+        self.tovic_debug_pub_.publish(viccan_to_string(msg))
 
     def relay_fromvic(self, msg: VicCAN):
-        """Relay a string message from the MCU to the appropriate VicCAN topic"""
+        """Relay a message from the MCU to the appropriate VicCAN topic"""
-        msg.header = Header(stamp=self.get_clock().now().to_msg(), frame_id="from_vic")
-
         if msg.mcu_name == "core":
             self.fromvic_core_pub_.publish(msg)
         elif msg.mcu_name == "arm" or msg.mcu_name == "digit":
@@ -139,10 +187,12 @@ class Anchor(Node):
             self.fromvic_bio_pub_.publish(msg)
 
     def on_mock_fromvic(self, msg: String):
+        """Relay a message as if it came from the MCU"""
         viccan = string_to_viccan(
             msg.data,
             "mock",
             self.get_logger(),
+            self.get_clock().now().to_msg(),
         )
         if viccan:
             self.relay_fromvic(viccan)
@@ -158,16 +208,9 @@ def main(args=None):
 
         rate = anchor_node.create_rate(100)  # 100 Hz -- arbitrary rate
         while rclpy.ok():
-            anchor_node.read_MCU()  # Check the MCU for updates
+            anchor_node.read_connector()  # Check the connector for updates
             rate.sleep()
     except (KeyboardInterrupt, ExternalShutdownException):
         print("Caught shutdown signal, shutting down...")
     finally:
         rclpy.try_shutdown()
-
-
-if __name__ == "__main__":
-    signal.signal(
-        signal.SIGTERM, lambda signum, frame: sys.exit(0)
-    )  # Catch termination signals and exit cleanly
-    main()

src/anchor_pkg/anchor_pkg/connector.py

@@ -1,7 +1,8 @@
 from abc import ABC, abstractmethod
 from astra_msgs.msg import VicCAN
+from rclpy.clock import Clock
 from rclpy.impl.rcutils_logger import RcutilsLogger
-from .convert import string_to_viccan
+from .convert import string_to_viccan as _string_to_viccan, viccan_to_string
 
 # CAN
 import can
@@ -39,18 +40,36 @@ class DeviceClosedException(Exception):
 
 class Connector(ABC):
     logger: RcutilsLogger
+    clock: Clock
 
-    def __init__(self, logger: RcutilsLogger):
+    def string_to_viccan(self, msg: str, mcu_name: str):
+        """function currying so that we do not need to pass logger and clock every time"""
+        return _string_to_viccan(
+            msg,
+            mcu_name,
+            self.logger,
+            self.clock.now().to_msg(),
+        )
+
+    def __init__(self, logger: RcutilsLogger, clock: Clock):
         self.logger = logger
+        self.clock = clock
 
     @abstractmethod
-    def read(self) -> VicCAN | None:
+    def read(self) -> tuple[VicCAN | None, str | None]:
+        """
+        Must return a tuple of (VicCAN, debug message or string repr of VicCAN)
+        """
         pass
 
     @abstractmethod
     def write(self, msg: VicCAN):
         pass
 
+    @abstractmethod
+    def write_raw(self, msg: str):
+        pass
+
     def cleanup(self):
         pass
 
@@ -61,8 +80,8 @@ class SerialConnector(Connector):
     serial_interface: serial.Serial
     override: bool
 
-    def __init__(self, logger: RcutilsLogger):
+    def __init__(self, logger: RcutilsLogger, clock: Clock):
-        super().__init__(logger)
+        super().__init__(logger, clock)
 
         ports = self._find_ports()
 
@@ -136,34 +155,36 @@ class SerialConnector(Connector):
                     )
 
             if serial_interface.is_open:
+                # turn relay mode off if it failed to respond with its name
+                serial_interface.write(b"can_relay_mode,off\n")
                 serial_interface.close()
         except serial.SerialException as e:
             self.logger.error(f"SerialException when asking for MCU name: {e}")
 
         return None
 
-    def read(self) -> VicCAN | None:
+    def read(self) -> tuple[VicCAN | None, str | None]:
         try:
             raw = str(self.serial_interface.readline(), "utf8")
 
             if not raw:
-                return None
+                return (None, None)
 
-            return string_to_viccan(raw, self.mcu_name, self.logger)
+            return (
+                self.string_to_viccan(raw, self.mcu_name),
+                raw,
+            )
         except serial.SerialException as e:
             self.logger.error(f"SerialException: {e}")
             raise DeviceClosedException(f"serial port {self.port} closed unexpectedly")
-        except TypeError as e:
-            self.logger.error(f"TypeError: {e}")
-            raise DeviceClosedException(f"serial port {self.port} closed unexpectedly")
         except Exception:
-            pass  # pretty much no other error matters
+            return (None, None)  # pretty much no other error matters
 
     def write(self, msg: VicCAN):
-        # go from [ w, x, y, z ] -> "w,x,y,z" & round to 7 digits max
+        self.write_raw(viccan_to_string(msg))
-        data = ",".join([str(round(x, 7)) for x in msg.data])
+
-        output = f"can_relay_tovic,{msg.mcu_name},{msg.command_id},{data}\n"
+    def write_raw(self, msg: str):
-        self.serial_interface.write(bytes(output, "utf8"))
+        self.serial_interface.write(bytes(msg, "utf8"))
 
     def cleanup(self):
         self.logger.info(f"closing serial port if open {self.port}")
@@ -175,17 +196,26 @@ class SerialConnector(Connector):
 
 
 class CANConnector(Connector):
-    def __init__(self, logger: RcutilsLogger):
+    def __init__(self, logger: RcutilsLogger, clock: Clock, can_override: str):
-        super().__init__(logger)
+        super().__init__(logger, clock)
 
         self.can_channel: str | None = None
         self.can_bus: can.BusABC | None = None
 
-        if self.can_channel is None:
         avail = can.interfaces.socketcan.SocketcanBus._detect_available_configs()
 
         if len(avail) == 0:
             raise NoValidDeviceException("no CAN interfaces found")
+
+        # filter to busses whose channel matches the can_override
+        if can_override:
+            avail = list(
+                filter(
+                    lambda b: b.get("channel") == can_override,
+                    avail,
+                )
+            )
+
         if (l := len(avail)) > 1:
             channels = ", ".join(str(b.get("channel")) for b in avail)
             raise MultipleValidDevicesException(
@@ -208,9 +238,9 @@ class CANConnector(Connector):
             )
 
         if self.can_channel and self.can_channel.startswith("v"):
-            self.logger.warn("using virtual CAN interface; this is likely vcan*")
+            self.logger.warn("likely using virtual CAN interface")
 
-    def read(self) -> VicCAN | None:
+    def read(self) -> tuple[VicCAN | None, str | None]:
         if not self.can_bus:
             raise DeviceClosedException("CAN bus not initialized")
 
@@ -221,7 +251,7 @@ class CANConnector(Connector):
             raise DeviceClosedException("CAN bus closed unexpectedly")
 
         if message is None:
-            return None
+            return (None, None)
 
         arbitration_id = message.arbitration_id & 0x7FF
         data_bytes = bytes(message.data)
@@ -244,7 +274,7 @@ class CANConnector(Connector):
             self.logger.warn(
                 f"received CAN frame with unknown MCU key {mcu_key}; id=0x{arbitration_id:X}"
             )
-            return None
+            return (None, None)
 
         data: list[float] = []
 
@@ -256,7 +286,7 @@ class CANConnector(Connector):
                     self.logger.warn(
                         f"received double payload with insufficient length {len(data_bytes)}; dropping frame"
                     )
-                    return None
+                    return (None, None)
                 (value,) = struct.unpack("<d", data_bytes[:8])
                 data = [float(value)]
             elif data_type_key == 1:
@@ -264,7 +294,7 @@ class CANConnector(Connector):
                     self.logger.warn(
                         f"received float32x2 payload with insufficient length {len(data_bytes)}; dropping frame"
                     )
-                    return None
+                    return (None, None)
                 v1, v2 = struct.unpack("<ff", data_bytes[:8])
                 data = [float(v1), float(v2)]
             elif data_type_key == 2:
@@ -272,17 +302,17 @@ class CANConnector(Connector):
                     self.logger.warn(
                         f"received int16x4 payload with insufficient length {len(data_bytes)}; dropping frame"
                     )
-                    return None
+                    return (None, None)
                 i1, i2, i3, i4 = struct.unpack("<hhhh", data_bytes[:8])
                 data = [float(i1), float(i2), float(i3), float(i4)]
             else:
                 self.logger.warn(
                     f"received CAN frame with unknown data_type_key {data_type_key}; id=0x{arbitration_id:X}"
                 )
-                return None
+                return (None, None)
         except struct.error as e:
             self.logger.error(f"error unpacking CAN payload: {e}")
-            return None
+            return (None, None)
 
         viccan = VicCAN(
             mcu_name=mcu_name,
@@ -295,7 +325,11 @@ class CANConnector(Connector):
             f"decoded as VicCAN(mcu_name={viccan.mcu_name}, command_id={viccan.command_id}, data={viccan.data})"
         )
 
-        return viccan
+        return (
+            viccan,
+            f"{viccan.mcu_name},{viccan.command_id},"
+            + ",".join(map(str, list(viccan.data))),
+        )
 
     def write(self, msg: VicCAN):
         if not self.can_bus:
@@ -403,6 +437,9 @@ class CANConnector(Connector):
             self.logger.error(f"CAN error while sending: {e}")
             raise DeviceClosedException("CAN bus closed unexpectedly")
 
+    def write_raw(self, msg: str):
+        self.logger.warn(f"write_raw is not supported for CANConnector. msg: {msg}")
+
     def cleanup(self):
         try:
             if self.can_bus is not None:
@@ -413,11 +450,15 @@ class CANConnector(Connector):
 
 
 class MockConnector(Connector):
-    def __init__(self, logger: RcutilsLogger):
+    def __init__(self, logger: RcutilsLogger, clock: Clock):
-        super().__init__(logger)
+        super().__init__(logger, clock)
+        # No hardware interface for MockConnector. Publish to `/anchor/from_vic/mock_mcu` instead.
 
-    def read(self) -> VicCAN | None:
+    def read(self) -> tuple[VicCAN | None, str | None]:
-        return None
+        return (None, None)
 
     def write(self, msg: VicCAN):
-        print(msg)
+        pass
+
+    def write_raw(self, msg: str):
+        pass

src/anchor_pkg/anchor_pkg/convert.py

@@ -1,27 +1,19 @@
 from astra_msgs.msg import VicCAN
+from std_msgs.msg import Header
+from builtin_interfaces.msg import Time
 from rclpy.impl.rcutils_logger import RcutilsLogger
 
 
-def string_to_viccan(msg: str, mcu_name: str, logger: RcutilsLogger):
+def string_to_viccan(
+    msg: str, mcu_name: str, logger: RcutilsLogger, time: Time
+) -> VicCAN | None:
     """
     Converts the serial string VicCAN format to a ROS2 VicCAN message.
     Does not fill out the Header of the message.
-    On a failure, it will log at a debug level why it failed.
+    On a failure, it will log at a debug level why it failed and return None.
-
-    Parameters:
-      * msg: str
-        - The message in serial VicCAN format
-      * mcu_name: str
-        - The name of the MCU (e.g. core, citadel, arm)
-      * logger: RcutilsLogger
-        - A logger retrieved from node.get_logger()
-
-    Returns:
-      * VicCAN | None
-        - The VicCAN message on a success or None on a failure
     """
 
-    parts: list[str] = msg.split(",")
+    parts: list[str] = msg.strip().split(",")
 
     # don't need an extra check because len of .split output is always >= 1
     if parts[0] != "can_relay_fromvic":
@@ -34,8 +26,37 @@ def string_to_viccan(msg: str, mcu_name: str, logger: RcutilsLogger):
         logger.debug(f"got garbage (too many parts) CAN data from {mcu_name}: {msg}")
         return None
 
+    try:
+        command_id = int(parts[2])
+    except ValueError:
+        logger.debug(
+            f"got garbage (non-integer command id) CAN data from {mcu_name}: {msg}"
+        )
+        return None
+
+    if command_id not in range(64):
+        logger.debug(
+            f"got garbage (wrong command id {command_id}) CAN data from {mcu_name}: {msg}"
+        )
+        return None
+
+    try:
         return VicCAN(
+            header=Header(
+                stamp=time,
+                frame_id="from_vic",
+            ),
             mcu_name=parts[1],
-        command_id=int(parts[2]),
+            command_id=command_id,
             data=[float(x) for x in parts[3:]],
         )
+    except ValueError:
+        logger.debug(f"got garbage (non-numerical) CAN data from {mcu_name}: {msg}")
+        return None
+
+
+def viccan_to_string(viccan: VicCAN) -> str:
+    """Converts a ROS2 VicCAN message to the serial string VicCAN format."""
+    # go from [ w, x, y, z ] -> ",w,x,y,z" & round to 7 digits max
+    data = "".join([f",{round(val,7)}" for val in viccan.data])
+    return f"can_relay_tovic,{viccan.mcu_name}{data}\n"