Mecanum Implementation in LabView

Previous question resolved. New question: When we slide to the right, the voltage drops to below 9 volts and kills the robot. This only happens when we try to strafe/run diagonally right.
This was a problem on the Ultimate Ascent robot we built except it was to the left instead. We haven’t figured out the problem for this yet.
Is it a coding problem?
Or a wiring problem?

Previous question resolved, new one now, the cRIO wipes the code every time we do a power cycle.
We’ve checked the little box during imaging for labview, and it doesn’t keep the code.
In LabView, we are trying to invert the motors and it would give me the problem attached.

It looks like you attached a PWM enum type to the true/false type of the invert motor inputs.

You need to delete that data connection, then hover over the Invert input until you see the wire spool cursor, then right-click and choose Create->Constant.

It should create the correct T/F input.

It should look like this:

Okay I got that on the program…
Now to redeploy to the robot.
Since we’re on the topic of deploying code, the cRIO wipes the code every time we do a power cycle.
We’ve checked the little box during imaging for labview, and it doesn’t keep the code.

Are you doing the explicit steps to compile and download the code to the robot?
On the Project Explorer window expand Build Specifications, then right-click on the entry under that for the pop-up menu:

  1. Build
    *]Run as startup
    or are you using the Run arrow (Debug-only)?

On the bottom of your Project Explorer, you will see “Build Specifications”. Expand that, and you will see “FRC Robot Boot-Up Deployment”. Right click on this and select “Build”. This will build your project (it does not need an active connection to the robot to do this). Once this has completed, right click again and select “Run as Startup”. When it has completed, it will ask you if you want to reboot the controller (select yes, it will reboot automatically). Your code should then be persistent on the controller.

Cool! Thanks guys.
Now onto the next problem… haha
When we slide to the right, the voltage drops to below 9 volts and kills the robot. This only happens when we try to strafe/run diagonally right.
This was a problem on the Ultimate Ascent robot we built except it was to the left instead. We haven’t figured out the problem for this yet.

Define “kills the robot”. Does it lose communication with the Driver Station?

Strafing will take much more power than simply going forward/backwards. Try using a fully charged battery and see if it clears up. If not, check your wiring. Remember that the 12 volt to 5 volt converter for the radio MUST be in the dedicated 12 volt port on the front of the Power Distribution Board and the cRIO MUST use the 24 volt port located in the same area.

The robot loses communication with the driver station and disables the teleop.
Well it can’t be wiring, everything is wired correctly according to diagrams, and the battery was running at 12.4 volts with no load according to the driver station. When we strafe right it drops to nearly 9 volts. It doesn’t happen when we strafe left or move in any other direction.

If you’re ever losing communication, it can most certainly be a problem with the wiring. You say everything is wired correctly, but until you itemize every connection between the Power Distribution Board and the D-Link router we’re not going to know whether what you think is correct is actually the way it needs to be done.

The good news is that your issue is repeatable.

So make it happen again and collect as much data as you can about it to answer these questions…

The devices almost all have LEDs and a boot sequence. Does the cRIO reboot? Does the radio reboot? Does the camera reboot?

Look at the Charts tab of the DS. How low did the yellow voltage plot go before the disconnect?

If the radio is the only device to reboot, trace wires and verify that it is connected through the regulator and the special 12V connector on the end of the PD near the cRIO. The link below, radio section shows images.

http://wpilib.screenstepslive.com/s/3120/m/8559/l/92626-wiring-the-2014-frc-control-system

If it is just the cRIO, then verify it is connected to its special boosted location on the PD.

If these seem correct, it may be informative to measure with a multimeter to verify the regulation features are working properly.

That is enough If … then conjecture. Let us know the results of the test.

Greg McKaskle

We’ve noticed that one of the motors (specifically front right) gets hotter than the rest of the motors after a prolonged amount of use. There is one gearbox that binds slightly and wouldn’t spin as well as the others, and that might be what the motor is attached to.
Would that be the problem?

I’m not at all a wiring person but I’m guessing something related to backflow on the CIM?

On the gearbox that binds, open it up and check out the insides. On the gears inside the box, you will notice a small raised “flange” on one side of the gear right around the center. That little flange needs to go towards the case of the gearbox to keep it spaced away from the sides. When it is done right, all those flanges should be sitting right against the bearings in the case. Check to see if you don’t have gears facing the wrong way, as this could cause too much friction and bind it up.

Yeah I’m assuming that that’s one of the problems because the code we uploaded was autogenerated by LabView. It can’t have been a coding problem because that code wasn’t modified.