> For the complete documentation index, see [llms.txt](https://docs.arkelectron.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.arkelectron.com/products/sensor/ark-flow-mr/dronecan-messages.md). # DroneCAN Messages The ARK Flow MR outputs data using the DroneCAN protocol\ \ \ There are 3 onboard sensors with a corresponding message each. Optical Flow and Rangefinder data publishing is enabled by default. IMU data publishing must be enabled by setting the node parameter [CANNODE\_PUB\_IMU](/products/sensor/ark-flow-mr/firmware.md#node-parameters). * Optical Flow: `com.hex.equipment.flow` * Rangefinder: `uavcan.equipment.range_sensor` * IMU: `RawIMU` There are also messages all Nodes emit:\ * NodeStatus: `NodeStatus` * GetNodeInfo: `GetNodeInfo` #### Messages The DroneCAN messages can be found here: {% embed url="" %} *** ### `com.hex.equipment.flow` #### `Measurement` Full name: `com.hex.equipment.flow.Measurement` Default data type ID: 20200 ``` float32 integration_interval # Integration Interval in seconds float32[2] rate_gyro_integral # Integrated Gyro Data in radians float32[2] flow_integral # Integrated LOS Data in radians uint8 quality # Flow Data Quality Lowest(0)-Highest(255) Unitless ``` *** ### `uavcan.equipment.range_sensor` #### `Measurement` Full name: `uavcan.equipment.range_sensor.Measurement` Default data type ID: 1050 ``` # # Generic narrow-beam range sensor data. # uavcan.Timestamp timestamp uint8 sensor_id uavcan.CoarseOrientation beam_orientation_in_body_frame float16 field_of_view # Radians uint5 SENSOR_TYPE_UNDEFINED = 0 uint5 SENSOR_TYPE_SONAR = 1 uint5 SENSOR_TYPE_LIDAR = 2 uint5 SENSOR_TYPE_RADAR = 3 uint5 sensor_type uint3 READING_TYPE_UNDEFINED = 0 # Range is unknown uint3 READING_TYPE_VALID_RANGE = 1 # Range field contains valid distance uint3 READING_TYPE_TOO_CLOSE = 2 # Range field contains min range for the sensor uint3 READING_TYPE_TOO_FAR = 3 # Range field contains max range for the sensor uint3 reading_type float16 range # Meters ``` *** #### `RawIMU` Full name: `uavcan.equipment.ahrs.RawIMU` Default data type ID: 1003 ``` # # Raw IMU data with timestamps. # # THIS DEFINITION MAY BE CHANGED IN A NON-BACKWARD-COMPATIBLE WAY IN THE FUTURE. # # # Data acquisition timestamp in the bus shared time base. # uavcan.Timestamp timestamp # # Integration interval, seconds. # Set to a non-positive value if the integrated samples are not available # (in this case, only the latest point samples will be valid). # float32 integration_interval # # Angular velocity samples in radian/second. # The samples are represented in the body frame, the axes are ordered as follows: # 1. angular velocity around X (roll rate) # 2. angular velocity around Y (pitch rate) # 3. angular velocity around Z (yaw rate) # float16[3] rate_gyro_latest # Latest sample, radian/second float32[3] rate_gyro_integral # Integrated samples, radian/second # # Linear acceleration samples in meter/(second^2). # The samples are represented in the body frame, the axes are ordered as follows: # 1. linear acceleration along X (forward positive) # 2. linear acceleration along Y (right positive) # 3. linear acceleration along Z (down positive) # float16[3] accelerometer_latest # Latest sample, meter/(second^2) float32[3] accelerometer_integral # Integrated samples, meter/(second^2) # # Covariance matrix. The diagonal entries are ordered as follows: # 1. roll rate (radian^2)/(second^2) # 2. pitch rate (radian^2)/(second^2) # 3. yaw rate (radian^2)/(second^2) # 4. forward acceleration (meter^2)/(second^4) # 5. rightward acceleration (meter^2)/(second^4) # 6. downward acceleration (meter^2)/(second^4) # float16[<=36] covariance ```
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