HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

OF COURSE... "Murphy's Law" for a rookie team...

Our Victors controlling our arm rise/fall have suddenly stopped being Enabled... we use a PWM splitter from Slot 5 on the Digital Sidecar to command the two Victors that each spin a Window Motor that are combined to move a gear box...

Everything was working fine, has been working fine, until a team member pulled the PWM connector (from the Y-side) out of one of the two Victors (connected by the PWM Y-splitter) while they were ENABLED...

We have swapped out new cables... but here's the scratch-your-head part, we have five other Victors that work fine (4 CIMS, 1 bane bots gripper motor) and they enable just fine from their respective slots on the DS and when we move the new cable over to these Victors to test, they will SOMETIMES Enable and other times NOT Enable?!!

Where's the "flakiness" coming from? We've swapped-out the DS with a new one and have the same problem...

Could there be a voltage/amperage problem that causes DS "flakiness"? We get the MOST "flakiness" from when the PWM Y-splitter is attached from one DS slot to TWO Victors?!

IF we can't resolve this... I can't see how we can justify driving 14 hours each way from San Antonio to Kansas City...

THANK YOU in advance for help!

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

Two questions:

1) Have you removed the locking pins from your window motors? That can cause everything to bind up, causing some things to work one way but not others.
2) Are you sure you're not getting 12V from the Victor outputs? (It's not stated in the original post, so I figure it's worth asking. If you are, I bet it's the locking pins from above.)

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

It's not the Windows Motors as we have the same problem whether they're connected or not...

We can't get the TWO Victors that drive the TWO Windows Motors to ENABLE... BOTH Victors are connected to Slot 5 in the DS via PWM Y-splitter...

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

First, determine if the problem is with the PWM or with the Victors. Put the robot up on blocks and swap a PWM from a working Jag and move it to one of the questionable ones, if the victor works, your PWM is the problem. Otherwise, your victor is the problem and might need to be replaced. I would venture to say that more likely though, the PWM is the problem. The PWM connections on the Victors are kind of finicky. I find myself needing to unplug and replug the PWM several times to get it to work. Also, make sure that the PWM is pushed in all the way and not resting on a pin that is out of alignment. All of these would cause the victor to not receive a signal from the cRIO and not work.

Hope you get it fixed,

Patrick

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

We have tried switching the PWM from the windows motor Victors that aren't working with two of the CIM motor Victors and it is still not ENABLING consistently. Everything seems to be pushed in correctly, and we have, over the course of troubleshooting the problem, unplugged and replugged the PWM dozens of times. We are still getting a "flaky" voltage readout after all of these things.

The "flaky" readout is from the tip of the PWM, not the DS.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

Michael,
While the buffers on the DSC should be able to handle the removal of a PWM cable it is entirely possible that in trying to reinsert the cable a voltage was conducted backward into the DSC. The PWM cable does carry +5 volts and power common. The +5 volts is used to power the opto-couplers inside the Victors. My first recommendation is to find a new PWM cable and connect it in place of the PWM wiring currently on the robot. If the Victor then enables, you can guess that the 'y' cable or the PWM cables are at fault. If the Victor does not not enable as before, try connecting to a know good Victor. It is unlikely that the Victor could be damaged by pulling out the connector but it possible. I am guessing that you have checked that the PWM cable is fully inserted. These connectors do require some experience to get them fully into the connector body on the Victor. When fully inserted, 1/8" or less of the brown PWM connector is visible above the case of the Victor. Hope this helps. I would bet that the trip would not be in vain as other teams are sure to help you when you arrive.
Al

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

Just for the hell of it, try checking the voltage between your frame and any of the negative ports on your PD board. We had a problem last season where we were discharging voltage onto the frame and that F'ed all of the electronics up.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

Al,

We have replaced the PWM cables several times (including the Y-splitter), and we are still getting "flaky results". We also replaced the Victor and the DS, as said before. The PWM cable has been confirmed to be in there. So what we have basically done is confirmed that the PWM cable and the Victor itself is not at fault, and the PWM is fully inserted into the Victor.

We aren't sure what is left to troubleshoot at this point; we believe we have narrowed down the problem to either the PWM connected to the DS or the Victor, as when we checked the voltage from the tip of the PWM, it was fluctuating every time.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

The PD isn't in contact with the frame and shouldn't be discharging.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

I would try unplugging everything, from the cRIO to the motor and try brand new components where you can and hopefully in reassembling them you will fix the problem. It also is possible that you have multiple faulty PWM cables. I don't know why but it always seems that we have more that don't work than do work. Also, with the blinking light on the victor, it doesn't change color or pattern when you ENABLE/DISABLE the robot from the driver station right? If it does, it means that the PWM is not the problem, but overcurrenting or something else is going on.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

The blinking light on the Victor doesn't change color or pattern when we ENABLE/DISABLE the robot, it blinks at the same rate. However, we did rewire and put together a seperate PD and when we ENABLED the Victors that were plugged into it, they briefly turn red when we ENABLE.

As for your first idea of unplugging and putting in brand new components, we are planning on doing this as a last resort if we cannot troubleshoot and eliminate the problem.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

Look for grounding problems. If you leave out the ground lines to the DSC the PWM can become flaky. I had a team that left off the ground lines because they were not using any power on the DSC. Turns out you need them anyway.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

I also posted on your FB wall. Let me know if you're still having problems, I can probably drive down there Thursday if you need the help or possibly late Wednesday.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

James, THAT'S an awesome offer... we have to leave Thursday with the trailer to get to Cow Town by Friday afternoon... the students are flying Friday/Sunday... we'll be in my garage/shop starting today, Wednesday, at 5:00pm and we're removing/disassembling the entire electrical/electronic system and will rebuild on a table from scratch with new wiring... if we can get it to work properly, we'll scramble to get it re-installed and finish putting the arm ballast (surgical tubing) on in Kansas City... since we lost Mon-Wed dealing with this, we won't get to "detail" the robot and more importantly we'll miss the two days of practice with the newly grafted-on 148 Raptor gripper...

IF you can come here today... that would be awesome... we'll feed you well... ;-)

Please call me if this is something you can do today... THANKS!!

210-858-8575

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

To ALL who have replied with advice... THANK YOU, THANK YOU!

We _appreciate_ the time/effort of everyone who contributes to Chief Delphi... hopefully, someday soon we'll be experienced/seasoned enough to contribute advice ourselves... ;-)

--Michael Blake

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

We'll help out however we can when you arrive in KC. Things seem to be going smoothly with our robot, so our pit crew should be free to dig through our tools and spare parts to assist whenever possible. We are leaving school early to be there at 2:00 Friday when the doors open.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

Have you tried using a different port on the Digital Sidecar? Would a Jaguar work?

We have some really good electrical mentors on 1939. We'd be happy to help you out when you get to K.C. We hope you are able to make the trip!

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

Michael,
This experience will put you in a position to start. Let us know what you find.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

We experienced a similar problem at WPI this year. The problem disappeared when we re-imaged the cRIO to V29, even though we weren't using CAN. We never made any further inquiries into the problem, so I can't verify the validity of that fix. Regardless, I would try making sure the firmware on the cRIO is properly imaged. It doesn't hurt.

Jack

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

sorry if i missread it, have you tried to move the slot on the Digital Sidcar?
it could be that you messed up the slot 5. if it still doesnt work maybe try to not use a Y and see if that fixes it. i dont see where the flakyness could come from..

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

This was EXACTLY our problem... thanks so much for mentioning this!
Also I want to thank James Tonthat for coming down to help us as well!!

Thanks everyone for helping we really appreciate this... The robot is now working again. :)

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

When dealing with Victors and PWM cables, "seems to be" isn't good enough. :p Occasionally you need someone with years of experience to be able to tell that something literally doesn't feel right, and to apply the proper subtle touch to get the connector to seat properly.

That's the one thing about Victors I don't miss when using Jaguars instead.

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

L O L! I was thinking that was the issue! In reading the thread, I was just about to say something about this, based on the statement:

"The blinking light on the Victor doesn't change color or pattern when we ENABLE/DISABLE the robot, it blinks at the same rate."

******

The orange LED should stop blinking and remain SOLID ON when a Victor is enabled and neutral. When you said it kept blinking, that pointed directly to the PWM cable not being properly seated.

Sometimes you literally have to jiggle the crap out of the PWM cable in order for the connection to be true (sorry Al - sometimes you just have to get medieval on electrical components to get them to do your bidding) ;) .

Once the connection goes true, it tends to stay that way...unless the PWM cable wiggles loose. Once you know the PWM connection is good, HOT GLUE the PWM connector to the Victor housing to keep it in place - saves you a TON of headache later on!

3138 had this same problem this past build season when they called me kinda freaked out. They were about to throw their Victors out! They were not privy to the "Victor PWM cable shimmy".

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

***SORRY for the LATE posting here... after the Cow Town ThrowDown I started getting ill which led to an emergency hospitalization with some upcoming surgery to fix the situation... OF COURSE, I'm scheduling surgery _around_ the build-season... ;-)***

WELL... it turned out that the problem was proper insertion on the PWM connectors into the Victor sockets...

THANKS to James Tonthat/Texas Torque #1477 who was AWESOME with his last minute offer to drive down 90 minutes from Austin to San Antonio to help us troubleshoot the problem!!

Turns out you have to be VERY careful/precise with the insertion into the Victors... that's actually a skill you have to develop to get it _just_ right... ;-)

Re: HELP! Cow Town ThrowDown Partcipation in Jeopardy!
 

I hope all goes well with your surgery. Make sure you don't overdo it.

I needed some minor surgery last winter. I scheduled it for between ship day (bag day) and our Week 1 competition - the day before, in fact. My doctor let me go, but wouldn't let me drive to the event or do any lifting. I was still bleeding, but it all worked out. Try not to do anything stupid like that.