Polhemus Patriot & vvvv?

vvvv beta general
1

Hello!
I’ve got a big problem. I know that there is a Tracker device for Polhemus iso TrakII in vvvv but all i got is a lousy patriot tracker :). i really do not know how i get data from the tracker into vvvv can someone help me?

i setted up an vrpn server where i can gather data from but how? some one any idea? i am slightly desperated right now…

2

did you already tried to use the IsoTrak version?

in case it does not work, it should be definately possible to patch a driver in vvvv. Can you point us to a taxt file with a description of the serial command set of the Patriot? i can take a look.
RS232, Tokenizer and Ord should be valuable nodes for this topic

3

actually I never heard of VRPN before and just googled it. Looks like a VRPN node could be a reasonable extension to vvvv. In case you desparetely need this node, we can make you an offer for inclusion in the next release.

In case you dig up a documentation how a VRPN client communicates with a VRPN server over TCP/IP this could be an alternative strategy for patching a client. i spend 2 minutes on the website and found nothing. maybe someone else?

4

Hi!
i dont know if ihave catched u right but here is a part of the config file for vrpn.

  • ###############################################################################
  • Liberty Tracker. Runs a Polhemus Liberty tracker that is attached to a serial
  • port or USB port on this machine. Arguments that go on the first line
  • char name_of_this_device
  • char name_of_serial_or_usb_device
  • int baud_rate_of_serial_device (not used when the device is USB)
  • It is possible to add additional commands that will be sent to the tracker
  • by putting the backslash character () at the end of the config line. This
  • will cause the following line to be read in and sent to the Liberty during
  • the reset routine. You can add additional lines by putting a slash at the
  • end of each command line but the last. Each line will be sent to the Fastrak
  • with a newline at the end of it. If a line starts with an asterisk (*), then
  • it is treated as a line telling how long to sleep, with the integer number of
  • seconds following the *.

  • Example when Liberty is attached via USB

  • The BAUD Rate is needed, although it is not used

  • vrpn_Tracker_Liberty Liberty /dev/usb/ttyUSB0 115200

  • Example when Liberty is attached via Serial

  • vrpn_Tracker_Liberty Liberty /dev/ttyS0 115200
    vrpn_Tracker_Liberty Patriot COM1 57600

i just tried a NULL tracker as dummy. it is a bit more complicated i think as explained.
the whole problem is:
there is one laptop with the tracker and the server running… and another computer with vvvv running where i want to get the tracker position.

i got the server from a previus projekt where we used the tracker with Virtools and there there was a building block where u can say tracker and localhost (or any other ip) to use this trackerdata.

ok im not really into vvvv and the server code or stuff like that. but im willing to work on that :) thx for the quick help and hopefully it is going on ;)

5

www.vrpn.org is a great and easy to use site :rolleyes:

but however maybe this link helps out there are some explanations how to create a sender or stuff like that but i really cannot get, what they want to tell me how i creat one :( but i still read through…

6

used the tracker with Virtools and there there was a building
block where u can say tracker and localhost (or any other ip) to
use this trackerdata.

unfortunately vvvv doesnt provide a node like this up until now. we´d need to program one into vvvv, and the code on the VRPN page would be a great help in doing so. if you are able to touch money we can think about this. it can think of it being cheaper than buying an IsoTrak.

Apart from that there still might be the possibility of patching a driver: I spend some more twenty minutes trying to track down the data format how the devices communicate on a network level without using the provided VRPN DLLs. Unfortunately i did not find anything. Somebody needs to dig deeper here, or use something like EtherReal to observe the actual traffic on the net. It might be some really trivial format, it might be not. Depending on that it might or might not be feasible to create a patch which is able to speak to a VRPN server.

here is a part of the config file for vrpn.
sorry that doesnt help. check if polhemus provides a document of how to talk with the Tracker directly via RS232. The idea would be skipping VRPN here. The code within the IsoTrak node is not complicated at all, so this particular brand might be similarily simple to decode.

7

Hello again!
the problem is i cannot afford either an iso trak nor the development to bring up a node for that. :(
i borrowed the tracker from the univerity im studying at.

so i think the idea of patching a driver is the best solution.

im trieing to get more and deeper informatioen on how the tracker communicates with Rs232 and post it here…

8

maybe this helps:
http://www.vrgeeks.org/vrpn/tutorial---use-vrpn

i really would like to use it with Kinect andFlexible Action and Articulated Skeleton Toolkit (FAAST)

9

VRPN: A Device-Independent, Network-Transparent VR Peripheral System.
pdf