Victor 888 PWM Problems
 

Hello everyone!

I am here on behalf of FRC Team 5196, Breaking Bot, and we're experiencing some problems. After the second our kits arrived where we were hosting kickoff, we began to build the kit bot and finished it with in a few hours, as well as all of the programming aspects such as flashing the cRIO and the wireless bridge. When we finally set the robot on the ground to test it with a joystick, the Victor 888 motor controllers would not stop flashing amber/orange, which (according to the manual) indicates that they are receiving no PWM signal.

We disconnected one of them from the motor and hooked it's power and PWM cables to our only Jaguar motor controller and it worked completely fine. We then took the Victor 888 inside and tested it's PWM with an Arduino and oscilloscope and it was still creating the same problems.

Is anyone else experiencing these problems with the new Victor motor controllers, or does anyone know how we can troubleshoot the problem?

Thanks!
FRC Team 5196, Breaking Bot

Re: Victor 888 PWM Problems
 

Hey again!

After further investigation, we disassembled the Victor 888 and connected the Arduino directly into the sockets for the PWM connectors and it worked and turned a motor.

We confirmed this by reassembling the Victor and placing the PWM male cable as far into the socket as possible and tested the controller. This resulted in the flashing orange light. We then removed the shell of the Victor and placed the PWM male cable as far into the socket as possible again and tested the controller. This resulted in the controller detecting the PWM connection and spinning the motor.

With the shell removed from the controller, we tested the female socket to see where the PWM signal was not detected. The PWM signal was detected all throughout the female socket aside from being removed.

From our testing there is an issue with the shell interfering with the PWM connection with the motor controller.

Sorry for the double post, and hopefully other teams with the same problems see this!

Re: Victor 888 PWM Problems
 

Hey! A Dog IRL!

In your code, whether it be Labview, C++ or Java, have you set your motor controller type to the Victor type? FRC code is defaulted to Jaguar, and that doesn't work with Victor, so you'd have to change it, recompile, and load it back onto the bot.

Re: Victor 888 PWM Problems
 

Getting your PWM cables seating into a Victor with the shell on it is challenging. This is a good thing, it means that the cable is less likely to fall out at an inopportune time. You are most likely not getting the cable fully seated into the port.

Re: Victor 888 PWM Problems
 

Yeah, we actually fixed it by using 22 gauge wire and plugging that directly into the connectors as a temporary solution until we develop a better one. We have that connected to the PWM cable.

Re: Victor 888 PWM Problems
 

Make sure all your pins are straight before inserting the connector. You will need to put a fair amount force into the connector. It needs to go down quite a ways. Take it out and try again if you don't get it the first time.

Re: Victor 888 PWM Problems
 

Be careful with the "fair amount of force" thing. If it takes too much force, you're probably bending the pins.

Does anyone reading this have an 888 with the PWM connector fully seated? And if so, would you please measure and post how far the fully seated connector extends out from the body of the 888? If your installed connector substantially exceeds this measurement it is probably not fully seated.

Re: Victor 888 PWM Problems
 

That's why I said make sure the pins are straight, but yeah, don't apply too much force, and don't use an arbor press or a hammer or anything like that.

Re: Victor 888 PWM Problems
 

OK. Attached. About 0.26 inch, fully seated.

Re: Victor 888 PWM Problems
 

Victors have always been notorious for this problem. It takes a real knack to get them in right, especially when they're buried behind or under some other component, as they always are.

The Talons, which have the same style connection, don't seem to have this problem.

No idea why one would be better.

Re: Victor 888 PWM Problems
 

Did you test this with a motor to see if it worked?

Re: Victor 888 PWM Problems
 

Yes. The test data can be found here.

Re: Victor 888 PWM Problems
 

No, test the new KOP Victor 888 that you were able to plug PWM into.

Re: Victor 888 PWM Problems
 

If I read this correctly by the OP they say the Victors work with other forms of PWM source so to go to the next step.

Are the 3 power LEDs ALL on, on the digital side card?

Please make sure that the 6 volt jumper is removed on digital side car as well.

And one last thing, double check that the PWM cable is installed so that the grounds match.

Re: Victor 888 PWM Problems
 

Yes, test results are here.