Supported Sensors

Phidget Spatial


Sensor background and requirements

The PhidgetSpatial combines the functionality of a 3-axis compass, a 3-axis gyroscope, and a 3-axis accelerometer all in one convenient package. It has enhanced precision in the accelerometer when measuring less than ±2g, and enhanced gyroscope precision at speeds less than 100°/s. The transition from high precision to low precision mode and back is completely seamless and automatic.

Hardware requirements

  • An ECU with a USB port
  • An ECU with PolySync Core installed

Configuring the PolySync Core driver

Adding the sensor to the SDF

Using the Configurator tool, add a sensor node to the SDF.

The PhidgetSpatial ‘Node Interface’ name is phidget-spatial.

Validating the sensor is properly configured

If you’re approaching a new PolySync system or need to validate an existing configuration you can use the following checklist to ensure the sensor is properly configured.

Setup checklist

  • The sensor is connected to a USB port

Starting the PolySync driver

The configuration set in the Configurator is loaded from the SDF when the dynamic driver starts. It connects to the sensor through the USB port, requests the data, and waits for confirmation that the sensor configuration is valid.

When the dynamic driver receives the first packet of data, it begins processing and abstracting the data from the OEM data structure in a high-level hardware agnostic message type. In this case the IMU data is placed in a ps_imu_msg.

  1. Power the ECU on
  2. Optionally follow the set up checklist
  3. Start the PolySync Core manager
    • $ sudo service polysync-core-manager start
  4. Start the dynamic driver process

Starting the node manually on the command line

To start a dynamic driver node on the command line, the node must first be defined in the SDF using the Configurator application.

Each node defined in the Configurator has a unique node ID which points to the nodes configuration. This article explains how to find the node ID.

Command line flags and usage

Once the node ID is known (substitute for X), the dynamic driver node for the supported sensor can be started with the base command:

$ polysync-core-dynamic-driver -n X

Each sensor supports an array of command line arguments. To see a full list of command line arguments, pass the -h help flag:

$ polysync-core-dynamic-driver -n X -h  |  less

There’s a lot of output so we recommend you pipe the output to less, but it’s not required.

Flag Required Description Arguments
-d No enable additional debugging output in the interface
-e No export a JSON support string describing the interface, used by the SDF configuration tool
-h No Show the help message
-i <> No Use provided PAL interface file instead of what is stored in the SDF Path to the dyanmic driver interface PAL shared object library
-n <N> Yes SDF node configuration identifier for the node SDF node ID from the Configurator, [0-65536]
-o No Reserved
-O No check the node SDF configuration for required updates and exit option (returns exit status zero if no change required)
-p <file.plog> No Use provided logfile in Record and Replay operations instead of the default File path to a PolySync plog logfile
-s <psync.sdf> No Use provided SDF instead of the default File path to an SDF file
-u No Allow updates to the SDF configuration during the normal runtime if needed (does not exit)
-U No Update the node SDF configuration and exit
-w No Disable the hardware interface(s), allowing the node to run without hardware connected - also known as replay mode
DTC codes
DTC value DTC name Fault description Notes
304 DTC_NOINTERFACE Interface not available Activated when the sensor is not reachable at the port set in the Configurator; activated when the sensor becomes unreachable during runtime

Accessing sensor data

When the dynamic driver node is operating in an OK state then data is being published to the global PolySync bus, and any node can subscribe to the high-level message type(s) output by the dynamic driver node.

There are several tools that PolySync Core provides to quickly validate that data exists on the bus.

Access sensor data with PolySync nodes that subscribe to the sensor’s output message types.

Input / output message types

The Phidget Spatial dynamic driver node outputs the following message types to the bus. You can enable and disable the publishing of specific message types in the Configurator.

Message API Docs Notes
Publishes pre-defined ps_imu_msg Sensor Data Model

Platform motion message fields

Data Type Name Description Message field polulated by this sensor
ps_msg_header header PolySync message header. Yes
ps_sensor_descriptor sensor_descriptor Sensor descriptor. Yes
ps_timestamp timestamp Sample timestamp. Yes
ps_native_timestamp native_timestamp Native timestamp for the motion data sample. Provided by some devices. Check ps_native_timestamp.format for meaning. Format value PSYNC_NATIVE_TIMESTAMP_FORMAT_INVALID means not available. Yes
DDS_double orientation [4] Orientation quaternion. Value PSYNC_ORIENTATION_NOT_AVAILABLE means given axis component not available. [xyzw quaternion]
DDS_double rotation_rate [3] Rotation rate. Value PSYNC_ROTATION_RATE_NOT_AVAILABLE means given axis component not available. [xyz radians/second] Yes
DDS_double velocity [3] Velocity. Value PSYNC_VELOCITY_NOT_AVAILABLE means given axis component not available. [xyz meters/second] Yes
DDS_double acceleration [3] Acceleration. Value PSYNC_ACCELERATION_NOT_AVAILABLE means given axis component not available. [xyz meters/second^2] Yes

Filtering incoming data for this sensor

An application that subscribes to a given message type is able to see data from more than one sensor or source.

Applications can filter for specific sensors and data sources in the message callback in C applications, or the messageEvent in C++ applications.

Filter incoming messages for this sensor with ps_sensor_kind value 360.

You can find all sensor descriptor values in this article.