[EWCP] Beta Testing Cast with Jared from team 341

[thefro526]

This past week, we had the pleasure of recording a side cast on the 2012 Beta Testing Hardware and Software With Jared Russell from Team 341. For those of you who haven't been able to make it to a Beta Test Presentation, it's an excellent resource to keep in the loop.

Some of the topics we hit on:

-What is new to the control system in 2012
-The choices that teams will have to make (What language to use? To buy a new cRIO or not?)
-An overview of the hardware and software that has been beta tested, including lessons learned
-How the Microsoft Kinect works, how it works with the FRC control system, and what we learned about utilizing it effectively
-General best practices for an effective control system in 2012

The recording is available here: http://recordings.talkshoe.com/TC-98466/TS-569882.mp3 or it can be found on iTunes.

There is also a thread on FIRST forums for this: http://forums.usfirst.org/showthread.php?t=18372

[Peter Matteson]

Can you clarify one item for me from the cast.

Which controller is actually the more tollerant one of low battery voltage? It sounded like the cRIO 2 was but then I thought it some actually said it was the original cRIO.

Also if you could post the laptop specs you think are adequete for a driver station to run the Kinnect with minimal lag that would be appreciated since I think we will need to upgrade to run it.

Thanks!
Pete

[Akash Rastogi]

Originally Posted by Peter Matteson

Also if you could post the laptop specs you think are adequete for a driver station to run the Kinnect with minimal lag that would be appreciated since I think we will need to upgrade to run it.

Thanks!
Pete

Discussed it at Ramp Riot with Jared and before the EWCP cast, he recommends using a laptop with an i5 processor and at least 2 gigs of RAM (most laptops nowadays have above this anyway).

I believe anything above the power of the Atom processors should be adequate though along with the higher end AMD dual-core processors.

I'm sure Jared will chime in soon.

[thefro526]

Originally Posted by Peter Matteson

Which controller is actually the more tollerant one of low battery voltage? It sounded like the cRIO 2 was but then I thought it some actually said it was the original cRIO.

The cRio II should be more tolerant of low battery voltages. Sorry for any confusion.

[Mark McLeod]

Of course, if the lower voltage tolerance of the cRIO II becomes a factor on the robot, then the bridge is probably going to croak for an even longer recovery period.

[Jared Russell]

Peter:

Definitely the cRIO FRC-II. It is rated for 9-30VDC supply versus 19-30VDC for the original 8 slot model (via the 24V output from the PDB).

As for laptop specs for minimizing lag from the Kinect, unfortunately I can only offer you a couple of data points.

On our Toshiba netbook (very similar specs to the Classmate), we saw on average ~500-1000ms of latency from movement to robot response. With our core i5 laptop with 4GB of memory, we saw ~100-200ms of latency.* These numbers seem to be consistent with others doing the beta test. The difference in latency is tremendous when it comes to controlling the robot at anything above very slow speeds.

Since the "long pole in the tent" is the processing of the Kinect point cloud data (and not the FRC server application, driver station, or wireless link delay), you can actually test a candidate laptop for yourself before kickoff. If you download the Kinect SDK from here (http://kinectforwindows.org/) and install on a Windows 7 PC, you can run the "Skeleton Tracker" sample app and get a good feel for what latency you can expect for a given laptop.

* By the way, with some laptops you will notice much better performance when running on AC power than while on battery (due to power management settings on the PC).

[Akash Rastogi]

Jared, is it true that you will need Windows 7 on the laptop? (I forget where I read/heard that)

[Jared Russell]

(To use the Kinect) Yes. Currently, Windows 7 is all that is supported. I do not know of plans to support any other operating systems at this time.

[Tom Bottiglieri]

Originally Posted by Jared341

Peter:

Definitely the cRIO FRC-II. It is rated for 9-30VDC supply versus 19-30VDC for the original 8 slot model (via the 24V output from the PDB).

As for laptop specs for minimizing lag from the Kinect, unfortunately I can only offer you a couple of data points.

On our Toshiba netbook (very similar specs to the Classmate), we saw on average ~500-1000ms of latency from movement to robot response. With our core i5 laptop with 4GB of memory, we saw ~100-200ms of latency.* These numbers seem to be consistent with others doing the beta test. The difference in latency is tremendous when it comes to controlling the robot at anything above very slow speeds.

Since the "long pole in the tent" is the processing of the Kinect point cloud data (and not the FRC server application, driver station, or wireless link delay), you can actually test a candidate laptop for yourself before kickoff. If you download the Kinect SDK from here (http://kinectforwindows.org/) and install on a Windows 7 PC, you can run the "Skeleton Tracker" sample app and get a good feel for what latency you can expect for a given laptop.

* By the way, with some laptops you will notice much better performance when running on AC power than while on battery (due to power management settings on the PC).

The Kinect Server pipes over a socket, right?

I don't see why the sensor won't be connected to some mega box on the field and pumped to the teams' DS over the network. I don't think each team will be required to supply a Kinect and a beefy laptop for each match. Then again..

[Jared Russell]

Originally Posted by Tom Bottiglieri

The Kinect Server pipes over a socket, right?

I don't see why the sensor won't be connected to some mega box on the field and pumped to the teams' DS over the network. I don't think each team will be required to supply a Kinect and a beefy laptop for each match. Then again..

Yes, the Kinect server uses a simple socket that communicates directly with the Driver Station application. Currently, the Kinect server is launched when you start the Driver Station, which suggests to me that, at this time, it seems like a "bring your own laptop" CONOPS is what FIRST has in mind.

While the arrangement you speak of would make sense, I am not sure that it is in the cards for 2012. Even if it is, you will probably still want a decent laptop for pre-competition testing.

[Joe Ross]

Originally Posted by Tom Bottiglieri

The Kinect Server pipes over a socket, right?

I don't see why the sensor won't be connected to some mega box on the field and pumped to the teams' DS over the network. I don't think each team will be required to supply a Kinect and a beefy laptop for each match. Then again..

In this scenario, teams would have to upload their modified kinect server to the "mega box" on the field.

[Jared Russell]

Originally Posted by Joe Ross

In this scenario, teams would have to upload their modified kinect server to the "mega box" on the field.

That's a great point. The Kinect server application is free to be modified by the teams, which is an argument in favor of the "bring your own laptop" arrangement.