Hey guys. So I’m still very new to LabVIEW (though thankfully not to programming in general). I finally got our cRIO imaged today and managed to deploy the starting code that FRC provides – unedited – over to our cRIO.
The last two years we’ve used 2 logitech joysticks, but long story short, we’re switching to a controller this year and I do not have contact with our programmer for the last 2 years. Everything I learn will be from chief delphi, other online sources, and studying his code from last year.
So now my question: What’s different between coding for 2 joysticks and coding for a controller? It has two joysticks and a dpad as well as some buttons, but when I tried running the starting code with it, only the left joystick worked.
Rather than programming Joystick 1 and Joystick 2, each with 2 axes, do I need to program Joystick 1 with 4 axes and just make it so that the first 2 axes are the left joystick and the second 2 axes are the right joystick?
What else might I run into trouble with?
Thanks for any/all help! I’ll update this with a link to the specific Logitech controller we’re using in the morning when I’m at school
From your description, you have it under control. You may want to pay attention to the positive/negative direction of the coordinate system, but the change you described should work.
To tell the difference easily if it ever happens to you again, just open your Driver Station and go to Setup with the controller connected to the PC.
You’ll see a drag&drop list of all the joysticks connected (if a joystick doesn’t appear, just push a button on it and the list would refresh). The first joystick in the list is the one you set to “USB 1 port” in your code’s Begin.vi, the second is USB 2 etc.
You’ll also notice that a controller would only take one slot in said list, while your 2 older joysticks would take one slot each. So, going by this logic, you’d need to use just one reference for the controller in LabVIEW like you said. Some joysticks and controllers (typically the vast majority of them other than Logitech Attack 3 or Xbox 360 controller) are completely messed up when it comes to axes/buttons ordering, you can either fix that by utilizing the appropriate drivers or making a small LabVIEW program with indicators for all the joystick’s outputs and make a chart out of it.
Tip: In my experience, it’s much easier to test your code with joysticks though, especially the ones that have winch/throttle axes as they’re so flexible and you can assign certain tested variables to those extra axes and you get so many options with all these buttons on 2 joysticks. Plus, pulling the trigger feels MUCH more natural with a joystick to me when testing a shooting system, and the migration to a controller (in case the driver wants that) can be done very easily even without the robot between the end of the build season and the competition. But all in all it’s your choice of course
The attached picture shows how to show a button’s state on the panel of teleop. If you want to show it on the dashboard, that involves writing it to a SmartDashboard variable and modifying the dashboard. Fortunately, the default dashboard already shows the state of all buttons and several axes.
how do you get the Button 1 part? I got the JoystickGet.VI and tried right-clicking on the button area on its right side, but couldn’t figure out how to add a Button like in the picture
right-click -> Cluster, Class, Variant Palette -> Unbundle By Name
Then wire the resulting box to the output node on the Get (either Axes or Buttons).
The resulting box can be changed to the button/axis you want, or expanded to reveal several buttons/axes.
Another way, for looking at everything on the Joystick, is to right-click -> Create -> Indicator
for both the buttons and the axes.
Mark McLeod’s way to handle it is the best in that case (making an indicator for the entire cluster), but also note this:
In some cases, you may want to see what kind of data flows on a certain wire while running deployed code. In that case, you don’t have to create an indicator for each wire before running your code, simply press on the wire while the code is deployed and running to display a probe of its data.
I just made a program in LabVIEW (attached pictures of the Block Diagram and Front Panel). After making it as pictured, I plugged in my controller via USB port and clicked “Run Continuously” in LabVIEW
However none of the lights lit up when I pressed the buttons on the controller
Your program is only a sub vi and won’t perform on it’s own.
It’s missing some essential stuff like communication with the Driver Station that reads the joystick.
You also need to have the Driver Station app running along with your LabVIEW session.
It would be easiest if you created a default robot project, from the Getting Started window, then added your code to the project.
The default project has most of what you need already, including one joystick.
We can walk you through the steps to take. For example,
Create a Robot Project (inserting your team number into the IP address)
Expand the Team Code
folder 1. Edit the Teleop.vi
block diagram 1. To begin with use just the Joystick that is already there to display it’s buttons.
Open the Robot Main.vi
Press the Run
arrow to start your project 1. Plug your game controller into your laptop
Start the Driver Station app.
Go to the Driver Station Setup
tab and see if the game controller is listed on the right in the first/top position. If not then click and drag it up to the USB 1 spot. 1. Enable the Driver Station.
Go to the Teleop front panel to see your button displays.
As Mark pointed out, your VI was running on the PC, not on the cRIO. The WPILib VIs to read the joysticks don’t work that way, and will be zeroes instead. The Joystick VIs work via the driverstation protocol and the VIs read those values on the cRIO.
Thanks for the detailed help! I tried doing this however, after I deploy the code to the cRIO and open the drive station, it says I lose connection with the cRIO and boots me. Happened two times so far but I’ll try it more with another cable after school.
Also, running RobotMain.vi does not show the lights that I linked to the 12 buttons of joystick 1 in teleop. Should I run teleop.vi instead of RobotMain.vi?
You start the run from RobotMain because it’s at the top of the calling tree and starts everything else, so for instance, Begin.vi gets called to open all your devices before Teleop gets called to handle your driver controls.
Then you switch to the Teleop front panel to watch the indicators you added.
You should be running both LabVIEW and the Driver Station from the same laptop, same account.
Don’t switch accounts or anything like that.
It is also possible to run the Driver Station on a separate computer and the LabVIEW from a programming laptop. You just have to make sure the IPs don’t conflict, e.g., the Driver Station computer is 10.37.53.5, and the programming computer is 10.37.35.6
You will need to run RobotMain, and then on the driver station panel, enable the robot in teleop mode.
This is more complicated than it would need to be to simply read from a joystick, but that is because it is assuming that your purpose in doing this is to safely drive a robot on a FIRST field.
The DS actually reads the joysticks and communicates it to the robot. Your code reads the joystick settings from the robot service, and then you can turn on motors, etc. The DS and robotMain framework also control which code on your robot is actually executed and whether it is allowed to turn motors.
IT WORKED! HUZZAH!! I wish yall could have seen my reaction
I think my issue earlier was that the power cable from the cRIO to the Power Distribytion Board is… less than reliable. However this time I was able to MAKE SURE nothing happened, so I didn’t lose connection to the cRIO, so it worked flawlessly I was able to note which buttons corresponded to which “Buttons” in LabVIEW via the LED Lights vi.
Thank yall very much for the help (and patience). I really do appreciate it
I was able to note which buttons corresponded to which “Buttons” in LabVIEW via the LED Lights vi.