Having issues controlling multiple SPARKs

Our team is struggling with an issue controlling our SPARK motor controller, from the KOP. We use 4 SPARKs to controll our wheel’s cim motors, having two spark on each set of wheels.

Each time we test the SPARKs’ performance they oparate normaly when idle, that is they’re LED status is solid blue (Neutral brake). But when we try to oparate the SPARKs on teleop using Labview only two SPARKs activate (Proportianal foward or Proportianal reverse). After some troubleshooting we’ve found out that the problem is likely with the roboRIO not sending a signal to two PWM conection.

For example :
SPARK 0,1,2,3 are connected respectevly to the roboRIOs PWM connections and the PDPs power connections, when we tell all motors to move foward only SPARK 2 and 3 worked. then we switched SPARKs 0 and 1 to PWM connections 4 and 5, only 4 and 5 worked.
In other tests similar to the exanple SPARKs 0 and 1 worked (those connected to 4 and 5).

We’ve checked every where we could for the issue, we checked the power connection, used different cables, used different SPARKs and made sure all the SPARKs work proparly.
Does anybody know where the issue may arrise from?

This sounds more like a code issue than an electrical issue. If you can post your code, I’m sure someone much more versed in Labview than I can double check it. As long as the PWM cables are inserted, there should be no issue, since the 0 and 1 Channels work normally without the others.

It sounds like you are assigning two sparks that are controlling the same gearbox to two separate pwm ports… Don’t do that. For example if spark 1 and spark 2 are controlling two motors that are in the same gearbox, instead of connecting spark 1 and spark 2 to pwm 1 and 2 on the roborio, just split pwm 1 into 2 outputs and connect those to spark 1 and 2. Since the motors of a single gearbox will always have to be spinning in one direction, this will simplify your code, and also make sure it is impossible to make errors such as trying to spin two motors in the same gearbox in opposite directions.

Sounds like a good idea, heres the files for anyone interested : https://drive.google.com/file/d/0B24cp6tlyEDNNlUzRjBfZU5TbWc/view

Hi G3 6740,

I’m sorry that you are experiencing issues. It looks like your code link is not public. I went ahead and requested access for myself, but a public link may help get more eyes on your issue. Alternatively, you can send me a link directly through a private message or contact me through our website, www.revrobotics.com.

From your description, I would agree that this looks like code issue. Once I have access, I’ll take a look and see if I can pinpoint the issue.

-David