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Firstly I’m a complete beginner so please be kind to me. I’m creating a two wheel robot that can turn left and right and reverse with LED’s and it runs off myRio and wrote out what I want my code to do as shown in the first image. My professor then quickly drafted me some code to show me an example of what it looked like and now i am trying to replicate the picture I have of that code as I only have it saved as an image and can’t actually see the functions as shown in the second image. I’ve gotten so far with replicating the code on labview however don’t know how to implement the parts highlighted in yellow on the third image please help. My email is


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Message 1 of 19
I haven't looked at your pictures but, I'll pass on a lesson I learned from these forums while beating my own head against the same problem. Altenbach or someone may even post a link.

Don't try to reinvent ARCTANGENT!

"Should be" isn't "Is" -Jay
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Message 2 of 19

At this point of exploration, Leave all the hardware out of it and write a simple computer simulation that shows the result when you operate the controls.


Work out the logic until you are happy, then add the hardware. Start with the learning resources listed at the top of the forum.


Please offer us consistent pictures. For example your front panel does not contain anything labeled "Throttle" or "slide". Personally I probably would use a steering control that is zero for straight, negative for left, and positive for right. You can handle the math on the diagram accordingly. Same for the throttle.


Your diagram seems overly convoluted. I am sure it could be simplified dramatically!


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Message 3 of 19

"Enable", "Direction", & "Direction 2" are terminals of front panel controls.

The items with blue halos are Express VIs (I think from DAQ Assistant).

The "Simple Error Handler" is in: Functions → Programming → Dialog and User Interface.

"Reset" is probably under Functions → Instrument I/O.

Note: You can pin any palette, then click on "Search" to find a function.

"If you weren't supposed to push it, it wouldn't be a button."
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Message 4 of 19

@paul_cardinale wrote:

"Reset" is probably under Functions → Instrument I/O.

  • We can provide much better help if you attach entire VIs (a.k.a. "LabVIEW Code") rather than pictures of (portions of) the Block Diagram.  Imagine I showed you a printout of a 4-page listing of a C++ program, but it only showed, for example, the "True" branches of IF statements (hmm, I hope there are IF statements in C++).
  • Be sure to tell us which version of LabVIEW (2019?  earlier?  later?) and whether 32-bit or 64-bit LabVIEW (I'm pretty sure you'll need to be running 32-bit LabVIEW, on 64-bit Windows 10, of course).
  • I assume you have the myRIO Toolkit installed (which means you are running LabVIEW 2019 or earlier).  The myRIO Reset function can be found in the myRIO Palette under Device Management.
  • I absolutely agree with the earlier suggestions to initially "forget about the hardware" and figure out (pencil and paper are just fine) how to "model" how your two-wheel Robot will behave.
    • What happens if the wheels turn at the same speed?
    • What happens if one wheel turns at a rate of 75% of the other wheel?  How about 25%?  How about one wheel stationary?
    • What if the wheels turn at the same rate, but in different directions?
    • How does the size of the Robot influence its movement trajectory in the above cases?
  • How do you want to specify (i.e. control) the movement of the Robot?  I presume one component to control is velocity, presumably of the Robot's center.  Note this is easy to define/control if the Robot is moving in a straight line -- think about what you'd want to do if the Robot is moving in some other fashion.
  • Is there another Control that you might want to design?
  • You might want to know something about the Robot's Position and Orientation.  How would you express these (i.e. what is a convenient Coordinate system for each one)?  You might consider a pair of "Indicators" to show these.
  • Think about an Automobile.  The previous three points have analogs in a car (the third point has two indicators ...).  What (automobile) Control hasn't been mentioned (besides, of course, the Radio)?  Do you need to worry about it right now?

Once you have some idea of what you want to do, and what some Controls and Indicators might be useful, start sketching out how you might implement them.  To help you think "digitally", start with the Robot at rest at position 0, 0, with heading 0° (East -- do you understand why I chose East?  Think X-Y Coordinates ...).  How would you compute the position and heading at 1 second intervals, given that you know the Control setting at these same intervals?  [Make it easy on yourself -- start by varying only Speed.  What if you make Speed negative?  Can you do that in a car?].


Now learn a little LabVIEW.  Learn about Loops and Shift Registers (which let you keep track of things like Position and Heading that change at regular intervals) and the Wait (ms) function (that puts time into your loop so you can, in fact, make it run once/second).  Use Indicators to tell you where you are in space, as well as your current Heading, and try to "go somewhere".


Once you can do this "on the screen", you can start to worry about how to make your two-wheeled Robot, controlled by your myRIO, do the same thing.  It won't be that difficult if you already have a good idea of what you need to do!


Bob Schor

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Message 5 of 19

Thank you so much for replying but I can’t find the DAQ assistant this is what I’m seeing?

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Message 6 of 19



why do you look inside the ExpressVI palette when you want to look for MeasurementIO functions?


Did you install DAQmx?

Which version of DAQmx did install and which LabVIEW version do you use?

Did you install DAQmx in the right order (after your LabVIEW installation)?


Why do you ask for DAQAssistent at all when you want to work with your myRIO and the related myRIO functions???

Best regards,

using LV2016/2019/2020 on Win8.1/10+cRIO
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Message 7 of 19

One other thing to note (and I know I am way late to the party): Members here prefer that you upload your VIs instead of pictures. Try and Save to a Previous Version (LabVIEW 2018 - 18.0) should suffice for most members.


Stay away from loading images unless absolutely necessary

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Message 8 of 19

@Eric1977 wrote:

One other thing to note (and I know I am way late to the party): Members here prefer that you upload your VIs instead of pictures. Try and Save to a Previous Version (LabVIEW 2018 - 18.0) should suffice for most members.


Stay away from loading images unless absolutely necessary

Inline snippets are appreciated by those of us who post by phone....


Where is that LabVIEW viewer for mobile app anyway?Oh only 6 kudos? B@@÷+%$# 

"Should be" isn't "Is" -Jay
Message 9 of 19


please can someone create this for me in labview I cant find any icons and my project is due tomorrow. It's a two wheel robot powered by myrio and had left, right and reverse lights. Thank you 

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Message 10 of 19