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cRIO-FRC Training Video: Joystick Motor Control in 10 Minutes!

This is the first installment of cRIO-FRC training being produced by National Instruments. Expect more videos like this as well as text companion material in the next couple of weeks.

FIRST Robotics Competition: Joystick Motor Control in 10 Minutes

Please post feedback! We want to make our training material the best possible.

Cheers,

Mark

NI FIRST Support

Mark
NI App Software R&D
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Excelent! Excelent! Excelent! Excelent! I haven't seen the movie yet but this is extremely helpful! It gives us a good idea of how we control, communicate and oporate the cRIO

Thank you sooooo much!

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I finally saw the video and I am extremely impressed. Thank you so much, this is really helpful. It seems that we will be using pre-designed VIs for the FRC competition. They look nice and simple; similar to the Mindstorms NXT VIs. This is nice to know that it won't be so complecated. Opening up comunication looks very simple too. I especially like that.

Could you give a movie for all the people that love C+? I'm sure that they would appreaciate it. Or is WPI working on making the C+ default code? Would they be doing that? Or is it the other way around: that WPI is making the default code for LabVIEW? I think the former is what I heard.

Could you also explain more about the "IP address code" (that's probably not the right name) and the things that needed to be set in the beginning that were related to the network?

And what is the Watchdog VI for? To cancel this Watchdog option, yes, but what is Watchdog in the first place?

Thanks again,

LabViewEnthusiast

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LabViewEnthusiast wrote:

Could you give a movie for all the people that love C+? I'm sure that they would appreaciate it. Or is WPI working on making the C+ default code? Would they be doing that? Or is it the other way around: that WPI is making the default code for LabVIEW? I think the former is what I heard.

The C/C++ libraries are being created by WPI. Any training material for C/C++ will also be produced by WPI. Unfortunately I do not know the details of what WPI is planning. Here is a temporary link to Beta Documentation from WPI.

LabViewEnthusiast wrote:

Could you also explain more about the "IP address code" (that's probably not the right name) and the things that needed to be set in the beginning that were related to the network?

I am not sure I completely understand the question, but I will try and address it the best possible. In the video Ben gives his PC a static IP address that will place it on the same subnet as the cRIO-FRC, which also has a static IP address. In the video Ben uses a 255.255.255.0 subnet mask. In actual competition teams will be using a 255.0.0.0 subnet mask.

LabViewEnthusiast wrote:

And what is the Watchdog VI for? To cancel this Watchdog option, yes, but what is Watchdog in the first place?

The user Watchdog VIs are part of a safety feature that allows teams to setup watchdog functions on their cRIO-FRC. If the watchdog is enabled and not "feed" within a specified amount of time all motors and actuators are shut down. There will be example programs that ship with LabVIEW FRC Edition demonstrating this feature. It should be noted that in the latest builds of WPIlib the user watchdog is disabled by default, and does not need to be explicitly set to disabled as demonstrated in the video.

Mark
NI App Software R&D
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Thanks for your reply. It was very helpful.

One thing though. I understand what the watchdog feature is and that it is a safety feature, but what is an example where you would want to use it?

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It wasn't really clear to me, but I'm guessing that "LabVIEW 2009 FRC Edition" (as shown in the video) is not available for download yet. Is this the case? If not, I would really like to familiarize myself with the FRC-specific VI. Thanks!

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The LabVIEW FRC Editon 2009 will ship with the KOP. It is not available for download.

You can download the evalution version of LabVIEW 8.5.1 here.

Mark
NI App Software R&D
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@ LabViewEnthusiast wrote:

Thanks for your reply. It was very helpful.

One thing though. I understand what the watchdog feature is and that it is a safety feature, but what is an example where you would want to use it?

One example would be to use an accelerometer (to measure tilt) to check if the robot has been turned on its side. If the robot was knocked over you could use the watchdog to programmatically stop all of your motors and actuators from running.

Mark
NI App Software R&D
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Many times a watchdog is used to halt your system as a safety feature. If your program hangs because of a bug in your code, it causes the system to stop automatically.

As an analogy, imagine a burgler alarm where you have to call the police every hour. If someone breaks into your house and hurts you, you wouldn't be able to make your hourly call. The police would notice and come rushing to your house.

A software watchdog works the same way. Your code has to update the watchdog every so often. If the code doesn't update the watchdog because your code goes into an infinite loop, the watchdog automatically shuts down the robot outputs so that it doesn't go crashing into a wall.

Joel Sumner
NI-Shanghai
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are we going to be able to download and play with the Robotics VI's prior to recieving the LabVIEW FRC Edition 2009 in the KOP?

Around 3:45 into the video, Ben creates a new FRC cRIO Robot Project. Later in the video, Ben drops in pre-configured FRC VI's from the Robotics Library. Is this library and project available to download into my LabVIEW software? If so, how?

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