LabVIEW code to drive 4 motor chassis

[team5622]

Starting with the initial arcade mode robot project, we'd like to modify it to drive 4 motors instead of 2. We modified Begin to replace the Open 2 Motor control with an Open 4 Motor Control. The Open 4 Motor Control help does not list the Talon. We're using all Talons. Is this a problem?

We added the PWM controls and connected them to the Open 4 Motor.

That's basically it. I could maybe provide more details about what we did that didn't work, but I don't think that would help much. The 2 Talons we added do not light up like the first 2 do and the 2 new motors don't move.

We're looking for a simple way to drive our chassis with 4 motors instead of 2.

[GeeTwo]

Do you intend that the two additional motors will "slave" to the first two, or did you intend to control them independently?

If the former, then my recollection of the LWCVI class I took a few years back was that you just put the new motors in your wiring diagram near the old ones, and wire them with all the same inputs as the one's they're mimicking.

[team5622]

Yes. I want the two new motors to each do the exact same thing as one of the first two motors. We are trying to do what you say to do. Maybe I should post a pic of our block diagram.

[Mark McLeod]

Does your Open 4 Motor look like this?
You can drag and drop this picture into your Begin.vi to look at the actual code.

[team5622]

It looks amazingly similar, if not the same. I dropped the snippet in and compared manually. One difference: We have all 4 T/F inputs connected to boolean constants.

[team5622]

[ebmonon36]

You mentioned that the Talons don't light up like the others. Are you getting any lights on the Talons, or are they just not blinking red and green like the others? If the Talon lights stay orange, then it could be a PWM cable either not plugged in or faulty.

[team5622]

We may have zeroed in on LabVIEW code too quickly. We'll do some hardware swapping this afternoon. Thank you.

[team5622]

The problem was we were not deploying and running the code.

Now we have all the Talons lighting up and working. We've been playing with the Inverted options, but it seems like no matter what combination we use, we either can't turn or can't move at all. Should we be able to run 4 motors in arcade mode drive? We don't want tank because we have other plans for Joystick 2.

[team5622]

Success!!!! We just had to try enough combinations.

[Mark McLeod]

That should work alright then for four Talons.
The additional inverts are fine.

So,

• Double check the orientation of the PWM cables going to the two Talons that don't light up.
• Pull the breakers for the Talons that are working, then test using the unlit Talons to see if they output any power. It's possible they just need to be calibrated.
• You can also try taking one of the PWM cables running to a working Talon and connect it to one of the non-working Talons to see if it's the cable itself.