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ethz-asl / ethzasl_xsens_driver

Driver for xsens IMUs
BSD 2-Clause "Simplified" License
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SyncOut indication #75

Open koko19 opened 6 years ago

koko19 commented 6 years ago

I have configured MTI 10 to send sync out signal, and checked using oscilloscope that it indeed does it correctly. However I am unable to find a way to detect in which message sent by the driver to ros did the sync occur. Is this possible and if yes, could you please explain how?

fcolas commented 6 years ago

Disclaimer: I never used the synchronization settings and I'm not sure I find the documentation so clear. Also, I'm not sure what you exactly want to do, nor what is your configuration (you can help on this). But from what I gathered, if properly configured (TriggerIndication function), bit 22 of the StatusWord should contain tell you when the triggered occurred. This StatusWord is not published as an independent topic (for lack of need and well-defined interface), but you can get it from the imu_data_str topic. Can you check that it is the case?

koko19 commented 6 years ago

I have two cameras which I want to sync with IMU syncOut signal. Afterwards, in order to assign correct IMU measurements to images I have to know which IMU message contained sync signal. I have configured the IMU using the Xsens SDK to send syncOut every 50ms (20Hz) and I receive that signal on the oscilloscope, however the StatusWord in imu_data_str always remains the same. Here is an example:

data: "{'Acceleration': {'Delta v.z': -0.013541683554649353, 'Delta v.y': 0.020512893795967102,\ \ 'Delta v.x': 0.00022651255130767822, 'frame': 'ENU', 'accY': 8.205488204956055,\ \ 'accX': 0.08979009836912155, 'accZ': -5.4161858558654785}, 'Timestamp': {'PacketCounter':\ \ 17525, 'SampleTimeFine': 5375072}, 'Angular Velocity': {'Delta q1': -2.9886141419410706e-05,\ \ 'Delta q0': 1.0000001192092896, 'Delta q3': -3.993697464466095e-05, 'Delta q2':\ \ -1.4726073459314648e-05, 'frame': 'ENU', 'gyrZ': -0.03194957971572876, 'gyrX':\ \ -0.023908914998173714, 'gyrY': -0.011780858039855957}, 'Temperature': {'Temp':\ \ 31.0}, 'Status': {'StatusWord': 4194305}}"

StatusWord is always 4194305.

fcolas commented 6 years ago

This value has bit 22 on with means, according to the document “When SyncOut is active this bit will rise to 1”. Can you show the output of:

rosrun xsens_driver mtdevice.py -i
fcolas commented 6 years ago

@koko19 Did you find a way to achieve what you wanted?