V5 brain ports break continually


#1
While running the programs on our cars,certain motors ( always some concerned with claws or the motors connected to long wires) always stop suddenly and the red lights on motors start flickering. 
We've found that if we connect them to other ports,stopped motors work normally again.  But the ports these motors previously connected to break completely, and the new ports we use will also break after some time.

All of our V5 brains have such issue, and it seems to happen quite easily.
We’ve also checked our programs and our structures to avoid the motors from overload.
How to solve the problem?


#2

We also meet this problem.
This is S-E-R-I-O-U-S ! ! ! ! ! ! ! ! ! ! ! ! !

After the first week, four ports of two brains broke out. We thought that it might be our program mistake. So We just set the motor at speed zero.
BUT now our four v5 brain had 15 broken ports in all.
Please someone tell me what i did make this happen.


#3

It might be the cable connecting the motor to the V5 Brain. A few weeks ago we had the same issue and the motor was blinking red. Our team found out it was the wire, it needed to be rebuilt.


#4

If you haven’t already try updating the firmware on your brain. We found that the latest update made the system a lot more stable so it might have a fix for your problem.


#5

Are you saying that even after a restart, the ports that stopped working still don’t work?


#6

We’ve already updated the brains to the lastest version and changed the motors or cables, but the issue still not solved. Broken ports remains, and new ports keep breaking.
If the problem can’t be solved, we may not have enough ports to support our cars during competitions. :frowning:


#7

Have you contacted VEX Support?


#8

Do you plug and unplug the wires constantly? That might be a problem.


#9

The motor is in charge of reducing power if it overheats, that is not something handled by the V5 brain, so there should be no need to reset the brain. If you had a bad cable and short-circuited the power for a smart port, that port will be disabled, but only until the short is removed.


#10

Can you provide any more details ? How long are the “long wires” ? Did you make these yourself or are they the long smart cables provided by VEX ?
When the motor port stopped working, was the brain turned on ? Were you running a program ?


#11

Our team summarized some details.

  1. In the “device” window, the broken ports can detect which kind of device is plugged to it like the nomal ports, but the nomal ports feedback immediately while the broken ports need someone to reopen the device window.
  2. We can’t control the motors through the broken ports, using the smart cables provided by VEX .
  3. We all know that the red light of the smart ports will blink quickly when the motor is running ,but the red light of the broken ports will always turn on an,go off after 1 second and turn on repeatedly.
  4. We think it might be a software / system problem.
  5. ALL our broken ports was connected to long wires,but it might be by coincidence.
  6. We have motors running at much higher speed than thosed connected with the broken ports, but their ports never get a problem.

#12

Thanks for the feedback.


#13

The same as APTXOUS.
BTW all broken ports are using 1500mm cables provided by VEX.


#14

We see a slightly different symptoms which seem to be related rather to a mechanical design issues.

Our motors often go in and out of presence. If the program of the device info doesn’t see the motor, we just push on the connector a little and it will start working. Even with short cables. Even with the original pre-made cables, all with the official connectors.

What I have realized is that the connectors, well clicked into the socket, have a very significant play - I don’t remember seeing this problem or that amount of play with the beta HW.


#15

Thanks Petr. Yes, I don’t remember any problems of this sort reported with beta hardware.


#16

If I use an 80 meter wire will I encounter any problems? My robot is expanding really high


#17

I’d better avoid feeding trolls, though in Beta, I tried crimping the whole V5 cable stock (was it 25 or 50ft?) and used it for a single-motor RD4B. Worked like a charm with no discernible performance penalty.
Long cable will certainly eat into the cable and battery voltage drop budget that the motor usually compensates, but those 8+m caused no troubles and I doubt you really have that need :slight_smile:


#18

It’s pretty cool though that you can use really long cables though. The only problem I see is that if the write gets messed up at any point you have to replace the entire thing (unless there are connectors I am unaware of), but even if this happens you can easily make two shorter cables.


#19

I haven’t had the beta kit so I can’t compare but there is definitely a lot of play in the connectors with our production kit. I don’t think it causes any issues with our electrical connections though.


#20

While testing motors connected to normal ports in the ‘devices’ window the lights on the connectors flicker, which is normal.
But when our ports die, the lights seem to flicker more frequently.
If we test the motors on these broken ports in the ‘devices’ window after we stop the program, the lights won’t respond.