dvl_a50_serial_python

A ROS 2 driver for the Water Linked DVL A50, written in Python and communicating over a serial connection.

This package parses velocity, transducer, and dead reckoning data from the DVL hardware, translating it into standard ROS 2 topics and service handlers.

---

Features

• Parses DVL protocols: modern velocity reports (wrz), transducer metrics (wru), dead reckoning (wrp), version metadata (wrv), and configurations (wrc).
• Verifies checksums on incoming messages using a standard CRC-8 calculation.
• Supports dynamic parameter updates at runtime for device configuration.
• Provides standard service interfaces to calibrate the device, toggle acoustics, trigger pings, reset dead reckoning, and query configuration.

---

Configuration Parameters

All parameters can be configured via YAML parameters or overridden at runtime:

Parameter	Type	Default	Description
port	string	"/dev/dvl"	Serial device path.
baud_rate	int	115200	Baud rate of the serial connection.
frame	string	"dvl_a50_link"	Header frame ID for published messages.
speed_of_sound	double	1500.0	Target speed of sound in water (m/s).
mounting_rotation_offset	double	0.0	Mounting rotation offset (degrees).
led_enabled	bool	true	Enable or disable physical LEDs on the device.
range_mode	string	"auto"	Altitude search range specifier: "auto", "=a" (locked to mode 0-4), "a<=b" (search modes a through b), or "wt" (water tracking).
periodic_cycling_enabled	bool	true	Toggle periodic cycling modes.
enable_on_activate	bool	true	Auto-start acoustic pinging when the node starts.
topic_velocity	string	"velocity"	Topic name for DVL velocity data.
topic_dead_reckoning	string	"dead_reckoning"	Topic name for DVL dead reckoning data.
topic_odometry	string	"odometry"	Topic name for standard Odometry message outputs.
timeout_configure_ms	int	5000	Timeout limit for sending configurations.
timeout_reset_dead_reckoning_ms	int	5000	Timeout limit for resetting dead reckoning.
timeout_calibrate_gyro_ms	int	20000	Timeout limit for persistently calibrating the gyroscope.
timeout_trigger_ping_ms	int	5000	Timeout limit for manual ping triggers.
timeout_set_protocol_ms	int	5000	Timeout limit for setting the communication protocol.
timeout_get_config_ms	int	5000	Timeout limit for retrieving configurations.

---

ROS Interfaces

Published Topics

Topic Name	Message Type	Description
velocity	dvl_msgs/msg/DVL	Measured linear velocities, calculated FOM, altitude, status, and beam-by-beam metrics.
dead_reckoning	dvl_msgs/msg/DVLDR	Integrated 3D coordinates, orientation (Euler), status, and standard deviation.
odometry	nav_msgs/msg/Odometry	Fused robot state estimation: velocities and covariance are derived from wrz, while position and orientation are derived from wrp.

Services

Service Name	Service Type	Description
enable	std_srvs/srv/Trigger	Activates acoustic pings on the device.
disable	std_srvs/srv/Trigger	Deactivates acoustic pings on the device.
calibrate_gyro	std_srvs/srv/Trigger	Starts the persistent gyroscope calibration sequence (wcg\n).
reset_dead_reckoning	std_srvs/srv/Trigger	Resets the DVL's integrated coordinate frame back to zero (wcr\n).
trigger_ping	std_srvs/srv/Trigger	Triggers a single manual acoustic ping (wct\n).
get_config	dvl_msgs/srv/GetConfig	Queries the active operational parameters from DVL non-volatile memory.

---

Build and Run

Build the Package

From your ROS 2 workspace root directory:

colcon build --packages-select dvl_a50_serial_python

Launch the Driver

Run the driver using the default YAML parameters under the /dvl namespace:

ros2 launch dvl_a50_serial_python dvl_a50_serial_python.launch.py