Issues with Spark speed controllers

Technical Java
#1

This is a problem that a rookie team that I’m long-distance helping is having. I met with them on Saturday to teach the basics of programming in Java. They went home and they haven’t been able to get their Spark speed controllers working. When the robot is enabled, the Sparks continue blinking as if the robot was still disabled. My immediate thought is that it’s a wiring problem, but they’ve checked the wiring like ten times and it all looks fine. One thing I noticed is that they had the PWM cable coming from the roborio Y, so they can control two speed controllers with one pin on the roborio. I asked them to check it again and again, but it’s done correctly. The Sparks are created and used properly in the code, so I know the code (probably) isn’t the issue.

Spark leftSide = new Spark(0);
Spark rightSide = new Spark(1);

The PWM cables are plugged into PWM pins 0 and 1, for left and right. They aren’t plugged in backwards. The PWM cables are correctly plugged into the Sparks. The Y in the PWM cables have been done correctly. The PDP voltage and ground are going into the correct ports on the Sparks. The motor outputs are wired correctly. Am I missing anything physical?

On the programming side: The roborio has been properly imaged. Java has been deployed to the roborio. They are plugged in to the roborio via USB. They can deploy code just fine. They have the latest version of the NI Driver Station. When they enable it, the RSL built into the roborio flashes like it’s supposed to. One thing I noticed is they can’t get the actual big orange light to light up, which makes me wonder if the roborio has something wrong with it. They have JDK 8 and the latest version of the FRC Java plugins. The joystick is working properly. My next step code wise will be dumbing it down as far as possible. Am I missing anything code wise?

Any help is greatly appreciated!

1 Like
#2

I would suggest that you have them try an example robot java project to see if that fixes the issues (they would probably need to change the motor controllers though). Also, you might try changing sparks to talon (regular talon not srx) just to see if there is an issue with that specific import in their code.

Good luck!
#3

If the SPARKs are blinking blue or blinking yellow they are not getting any input signal. (SPARK Users Guide page 14)

Some decent resolution pictures of their setup might be helpful.

The RSL on the roboRIO is directly connected to the RSL output for the “big orange light” as far as I know, so that sounds like a wiring issue on the light more than a roboRIO issue. For the SPARK, maybe the PWM cable isn’t fully pushed in or pushed in crooked so it’s not actually making contact?

If there is example code available, I would try that. The SPARK will respond even if it’s configured in code as one of the other common speed controllers.

If you want to start up a support ticket with us at REV you can send an email to us at support@revrobotics.com and CC your Rookie team and we can also help that way.

#4