plug-in for Ascension MotionStar

[Eunice]

Hi,
We are having trouble to add Ascension MotionStar sensors in Vizard.

Is there a plug-in for Ascension MotionStar wireless sensors? I note there is only flockofbirds plug-in for Ascension in the Vizard25 plug-ins folder.

I also found a peripherals web page:
http://www.worldviz.net/peripherals/peripherals.html
But there's no demos for downloading at all.

any suggestions? Many thanks.

~ Eunice

[tobin]

The only support for Ascension products that we currently provide is our flock of birds plug-in. Unfortunatley we have not tested it on a Motion Star model and therefore do not know if it works for it too or not. Have you tried this?

[Eunice]

Thank you for your reply, tobin.

I tried flockofbirds using the following script:
------------
import viz

viz.go()

myTracker = viz.add('flockofbirds.dls') #McMaster_bike.dls') #dualflock.dls')
myObject = viz.add('ball.wrl')
myObject.link(myTracker)

def mytimer(num):
pos = myObject.get(viz.POSITION)
print 'My object is here: ', pos

viz.callback(viz.TIMER_EVENT,mytimer)
viz.starttimer(0,1.0,viz.PERPETUAL)
-------------

It doesn't show error, but seems that it couldn't read the tracking data when I moved the sensor. Here's the output:

----------------------
************************************************** *
* VIZARD 2.51c *
* *
************************************************** *

flockofbirds.dls WorldViz Flock of Birds Driver v0.1
Loading File: ball.wrl
My object is here: [0.45710232853889465, -0.45710232853889465, 0.45710232853889465]
My object is here: [0.45710232853889465, -0.45710232853889465, 0.45710232853889465]
My object is here: [0.45710232853889465, -0.45710232853889465, 0.45710232853889465]
My object is here: [0.45710232853889465, -0.45710232853889465, 0.45710232853889465]
...
------------------------

and the LED indicator on the backpack doesn't look right. We use MotionStar Wireless sensors. Normally the LED on the backpack, which connects to sensors, shows green if it talks to the base station. But when we run the vizard script above, the LED shows red/orange blink which means waiting for the base station.

We do have a software with the Wireless pack that can show the sensors' data, and when it runs the LED on the backpack is green.

I think that flockofbirds plug-in doesn't work for MotionStar Wireless.

Any suggestions? Many thanks.

[farshizzo]

Hi,

The flockofbirds plugin uses the following variables to initialize, make sure they are correct:

PORT_FOB - The serial port number which the motion star is connected to (default = 1)

NUM_FOB - The number of sensors that are plugged into the motion star (default = 1)

BAUD_FOB - The baud rate of the serial communication (default = 115200)

So, if you had 3 sensors connected on COM2, you would do the following:PORT_FOB = 2
NUM_FOB = 3
tracker_1 = viz.add('flockofbirds.dls')
tracker_2 = viz.add('flockofbirds.dls')
tracker_3 = viz.add('flockofbirds.dls')I realize that the MotionStar is capable of sending data over an Ethernet connection. If this is the case for you, then we will need to modify our plugin to support this, as it currently only checks the serial port.

[Eunice]

The MotionStar Wireless we use connects on COM1, and I'm only test one sensor (we actually have ten, but I only plug one sensor into the backpack). I did explicitly set PORT_FOB and NUM_FOB though the default values are correct:

########
PORT_FOB = 1
NUM_FOB = 1
tracker_1 = viz.add('flockofbirds.dls')

myObject = viz.add('ball.wrl')
myObject.link(tracker_1)
###########

Still, the LED on backpack doesn't show green, and the ball doesn't move when I move the sensor.

Any idea? Thank you.

[Eunice]

I got a reply from the Ascension technical support:

"An Ethernet plugin is REQUIRED to talk to a MotionStar Wired, Wireless, or the 3DNavigator.

If Vizard does not have an Ethernet MotionStar plugin (not the same as the serial Flock plugin) then the MotionStar Wireless system will not work.

The Ethernet MotionStar products use a different protocol for data, and are not compatible."

Will you please modify the code to support this? Many thanks in advance.

[tobin]

Yes, our understanding now is that Motion Stars (wired) come in two flavors, a Wired RS-232 and a Wired Ethernet. For the former, we have been informed by Ascension that the protocol is exactly the same as the Flock of Birds and therefore our existing driver should work fine. For the latter, a new driver is neccesary. We are obtaining such a device immediately and will create the required driver for the Wired Ethernet Motion Star. Apparently the Wireless Motion Star speaks the same protocol as the Wired Ethernet and therefore our new driver should work on the Wireless model as well.

We'll post when we have a working Ethernet driver.

[Eunice]

Okay, thanks for your help. Looking forward to the ethernet plugin.

[Eunice]

Hi
Do you have any idea when the MotionStar plugin will be ready? Our project is stuck without tracking data. Thanks.

[tobin]

Our Motion Star CPU card blew out 3 weeks ago and we only just got the replacement in so that's why we're so delayed. It will be addressed immediately this week and you'll hopefully soon have positive results.

Sorry for the inconvenience.

[tobin]

Here's our first release of the MotionStar plug-in for an ethernet based system. It requires that BASE.EXE be running on the server. For testing, simply place the attached .DLS file in your project folder and follow the example shown in the sample script.

Please let us know if this is working for you or not. We will be releasing a final version next week that includes more control but it would be useful to hear how this first pass works for you.

www.worldviz.com/download/files/MotionStarPlugin.zip

[Eunice]

It works! Thank you so much.

[Eunice]

One thing I'm not clear is the data format of output orientation. Which format it outputs, rotation, matrix, or quaternions, when I call sensor.get()?

It seems the data format is controlled by ethernet commands?

[farshizzo]

Hi,

The format of the orientation is in euler angles. It is values 3-5 in the data list.

[Eunice]

Thanks again for your help.

Using <node3d>.link, the linked object show very little movement, though the sensor moves over a big distance in the real world.

Do I have to manually get data from the sensor and translate the linked object to scale-up the movement?

[farshizzo]

Hi,

I just tried the MotionStar here, and the units seem to be accurate. Keep in mind that the units are in meters. If you want to scale the movement then you will need to get the data manually and apply the scale factor.

[Eunice]

Thanks again!

Is it possible to get the c++ source code of your MS plugin?

[tobin]

Yes, on an "as-is" basis. We will not provide free support for our plug-in C/C++ code. The license is also LGPL. The project is built with MSVC 7.

If you're interested, please let us know.