View Full Version : ROS + Kinetc

12-28-2012, 04:38 PM
So how do i connect my Kinetc sensor to my MB??? It has a weird USB looking connector... I did a bit of research and saw this cable: http://www.amazon.com/Xbox-360-Kinect-Hyperkin-AC-Adapter/dp/B0057K045O/ref=sr_1_4?rps=1&ie=UTF8&qid=1356728403&sr=8-4&keywords=Xbox+360+Kinect+AC+Adapter%2F+Power+Suppl y

It has USB and power... If i get that adapter do i need to use that power cable as well? or usb is enough??

Is there another kinetic available and i got the wrong one?

12-28-2012, 08:35 PM
There are two versions of the Kinect: Kinect for Windows (K4W) and the older Kinect Xbox360. The newer version can use 'near' mode with the Windows Kinect SDK, while the older Xbox360 version cannot use near mode. The older Xbox360 Kinect comes in two packages/bundles: one with an external power supply that transforms the custom USB-ish connector into a plain USB-A connector (bundled with Kinect Adventures or some similarly worthless thing), while the other is meant to plug directly into the newer Xbox360 using only the custom USB-ish connector. If you do not have the power supply with the converter plug on it, you should be able to get an inexpensive spare at a place like newegg or maybe best buy (the one you linked should work as well). Putting a Kinect on a bot involves cutting the power supply's cable and splicing on whatever connector you want to allow it to be powered off a 12V batttery (11.1V from a LiPo usually works well enough).

If you have not already bought the Kinect, you could always go with an ASUS Xtion PRO LIVE which is powered completely over USB but costs about $60 more than the Kinect. It does not have motors in the base or the really sophisticated microphone array, but it can output the QVGA-resolution depthmap at 60 fps instead of the 30 fps to which the Kinect is limited (default is VGA-resolution at 30 fps for both).

12-28-2012, 09:08 PM
I havent purchased it yet, but saw it at my friends house and saw the connector.. So i get a discount on the K4W i get it for $150 since im a student (http://www.microsoftstore.com/store/msstore/en_US/pd/productID.246711100/search.true)

So eventuallyi want my bot to visualize the room its at, be able to move with out hitting something (so it will have to create a map of its location)... I also like what maxell bot did on the chess board, so why not i want to be able to identify chess piece and be able to move them to a desired location...

I do see more documentation on the Kinect for my requirements should i consider the Asus one???
Also i just called game stop and they sell used kinetics with the ac adapter for $69.... So the K4W cost $150 is it worth it the extra money? what is this "near" mode you talk about?

edit: What is Near Mode? (http://www.microsoft.com/en-us/kinectforwindows/news/faq.aspx#)Near Mode enables the depth sensor to see objects as close as 40 centimeters and also communicates more information about depth values outside the range than was previously available. There is also improved synchronization between color and depth, mapping depth to color, and a full frame API.

12-28-2012, 09:09 PM
So the one for windows gets full power from a single USB? no need to get extra power adapter?

12-28-2012, 09:24 PM
The Kinect and Xtion are both based on PrimeSense depth sensing technology (a form of structured lighting with a custom IC to handle all calculations). PrimeSense created the OpenNI interface/consortium to allow it to sell its chips to multiple vendors and have the devices all work relatively well with the same code. ROS uses the openni interface, so the Kinect, Xtion, and PrimeSense DevKit all work equally well. The Xtion shares the DevKit's advantage of needing only a single USB-A connection for both data transfer and power. The Xtion is also able to produce the QVGA depth map at 60 hz instead of 30 hz, but that might not matter much to your application.

All Kinect sensors require 12V external power. The Kinect4Windows and the Kinect Xbox360 bundled with Kinect Adventures both include an external power supply that provides the 12V as well as converting the custom USB connector to a standard USB-A connector. Any Kinect can be powered directly through the custom USB connector available on newer revisions of the XBox360.

Unless someone has managed to get the Kinect4Windows near mode working under linux, it is not worth the additional cost over a Kinect Xbox360. IIRC, there was a wrapper of some sort that could allow one to access the Kinect4Windows drivers as if it were the OpenNI interface, but that is windows only and I don't remember it working all that well (or near mode being all that useful).

12-28-2012, 09:35 PM
so in your opinion the Xtion is a better bet?

12-28-2012, 09:57 PM
For a size comparison, see here (http://www.pointclouds.org/documentation/tutorials/openni_grabber.php).
The rest is simply "what do you want to do with it" and "how much are you willing to spend/hack" to get to that point. The kinect is cheap, but it requires external power and is quite bulky and heavy. The Xtion is small, lightweight, USB powered, but really expensive. Both should work fine with ROS, and I seem to remember Maxwell at one point using the PrimeSense Reference Design (although that might just be vague recollections of a garage sale thread).

12-28-2012, 10:15 PM
how is that Primesense Reference Design (http://www.primesense.com/?p=514)?? how does it compare with the Xtion??

12-28-2012, 10:22 PM
Not sure it is available anymore and I think it was about as expensive as the K4W and Xtion Pro Live (maybe more, don't remember). The Kinect and Xtion are essentially the same hardware as the Reference Design (note the name) stuffed into different packages with a few add-ons (microphone arrays, motors, etc.).

12-28-2012, 11:24 PM
I guess im between the regular kinetc with ac adapter for $69 used (from game stop) or the Xtion Pro Live for $160

Advantages of Xtion i guess are single cable for data and power, less weight, better quality, and smaller size wise,lower quality mic
Disadvantages: Doesnt have servo, price

Avatanges of Kinetc price, price, has a servo, and price again, bigger array mic.
Disadvantages: Quality, weight, size

Will probably order tomorrow so ill have a bit of time to research more

12-28-2012, 11:43 PM
The motor in the kinect is not meant for continuous usage. It is a very cheap dc motor with fragile plastic gears. It is meant to adjust the view a couple times when first starting, and then just sit there for an extended period of time. The pan-tilt mechanism for the kinect on Maxwell (and many others) is made of two AX-12. The kinect mounted on Darsha (http://forums.trossenrobotics.com/showthread.php?5500-DARSha-(or-the-thread-formerly-known-as-quot-Nexus-4WD-omni-wheel-platform-quot-)&p=52118#post52118) had the motor and base cut off of the kinect to decrease excess weight/bulk and make mounting a bit cleaner (stand-offs screwed into the security screw holes in the bottom of the kinect hidden under the plastic vent).

12-29-2012, 12:03 PM
Is there any disadvantage with the Asus one then?? (Besides price) any software issues?

12-29-2012, 04:26 PM

A quick check on the ros answers site lists a possible problem with the asus when used with groovy (very frequent updates as it is still in beta testing), but not sure if that occurs very often or if it applies only to the asus.

Also, the asus has rather fragile mounting tabs, so extra mounting support is recommended. The turtlebot mounting kit for the Xtion actually holds it from the sides instead of at the little mount, but IIRC fergs had designed a very nice 3D printed mount for the Xtion.

01-03-2013, 02:55 PM
So few days ago i went to a game stop and picked up the kinect with ac adapter for $69+tax and i got it plugged in and it turns on, i can see my self, blah blah, I'll start following that book you recommended today and hopefully learn from it.. Now i now see that the Kinect is bulky and heavy... I'm still thinking about returning it and getting the Asus one, just for weight reduction and being able to power the thing using only a single USB cable.

02-11-2013, 01:25 PM
Where can i get the brakets to mount my kinect into 2 ax-12 or something like it, any one sells them?

02-11-2013, 02:14 PM
We went cheap and kinda ugly. I cut the motor/base off the kinect, then screwed standoffs into the screw holes hidden under the plastic grate on the bottom of the kinect. Those short standoffs are connected to a piece of aluminium which is connected to a standard plastic ax dynamixel frame.

02-11-2013, 03:06 PM
So you kept the kinect stand? Was looking for a way of removing it, seems weak

02-11-2013, 03:10 PM
Maybe ill make my own, will try tonight

02-11-2013, 04:38 PM
No. I cut the little pyramid shaped base, and the motor contained within it, completely off the kinect while making sure not to damage the usb cable. (http://forums.trossenrobotics.com/gallery/showimage.php?i=4635&catid=member&imageuser=4806) There are some kits out there that keep it intact, but it was just extra weight and plastic getting in the way, so I removed it. There are four or six screws in the bottom of the kinect hidden underneath the plastic vent (you have to pry it off). They are torx security bits, but can be removed pretty easily (http://forums.trossenrobotics.com/showthread.php?5500-DARSha-(or-the-thread-formerly-known-as-quot-Nexus-4WD-omni-wheel-platform-quot-)&p=52118#post52118). I removed the two torx screws closest to the center of the kinect. I then screwed two M3 or #4-40 screws through holes in a sheet of aluminium and into the plastic holes formerly occupied by the torx screws. The kinect is separated from the aluminium sheet by two 1/4" aluminium standoffs.

{__________________} <- kinect
||| ||| <- screws and standoffs
-------------- <- aluminium plate/sheet
|| || <- dynamixel bracket
~~~ <- dynamixel servo

02-11-2013, 04:47 PM
Not the site I was looking for, but works just as well as a teardown guide:


02-11-2013, 06:30 PM
so any m3 screw will fit on the screws that are covered by a xbox360 label? 1 at each side of the current base?

02-11-2013, 06:48 PM
Also how do you get rid of that plastic thing that hangs out at the end? the cable cover? (http://hsi.gatech.edu/hrl-wiki/images/d/d1/Kinect_mount12.jpg)

02-11-2013, 07:03 PM
I appear to have disposed of the receipt bearing the screws, but I have another with 1/4" long aluminium spacers for #6 screws. I do remember that I bought the screws at least an inch long and had to cut them down a bit to keep the kinect snug against the spacers. The screws were a bit smaller than the inner diameter of the spacers and I also seem to remember the screws not threading into the bolt cutter holes of the wire strippers, so I am quite certain I used M3 with the largest threads I could find. Either M3 or #4-40 should work, but all else fails, then you could do what I did and take one of the existing screws into a hardware store and directly compare and contrast with their offerings.

02-11-2013, 07:08 PM
The white plastic ball or the black rubber stress relief molding on the cable? The ball can be cut off with a pair of wire cutters. The black rubber on the cable was injection molded onto the cable and can be cut down to size, but do not attempt to pull it off or cut it completely flush with the rest of the cable or you will end up cutting into the shielding wire mesh wound around the USB cable.

The two tiny little wires that connected to the motor can be snipped off. If you want, you could further disassemble the kinect and unplug it from the board inside, but it shouldn't hurt to leave it as long as they do not short together.

02-11-2013, 09:16 PM
Taking about this: 4514

02-11-2013, 09:20 PM
i did trimed it all the way down, looks ok i guess.. Not sure if i can open it and remove the entire thing.. Anyways the plastic piece will cover that out.

02-11-2013, 11:19 PM
If you pry the two plastic grates off and remove the screws hidden underneath, then you will be able to safely slide the front and back of the shell off and completely remove the white plastic before reassembling.