Pneumatic Solenoid Firing Bug freezing robot

Hey all,

We have an odd bug, and we’re not sure if it’s software or hardware.

We’re running command-based Java and all REV electronics, including the REV pneumatics hub.

After we run any command that uses pneumatics, at some point later the last solenoids to fire will do so again, several times–both the timing and the number of additional fires are inconsistent. This has no effect on the mechanical position of any mechanisms.

3015 said the same thing happened last year for them using the REV Pneumatics Hub in that the solenoids would randomly re-fire a few times, but they said it caused no other issues and they were unable to chase down the problem. So we ignored it.

But today under teleoperated control, we discovered that while it happens the robot stops dead (and then resumes normal operation).

Has anyone seen this? Any idea what the cause might be, and how to get rid of it?


Check your laptop being used for driver station for high packet loss? We’ve experienced this when a laptop needed to be restarted or replaced due to the network card starting to fail. Increased memory also seems to help, as well as shutting down background processes. That’s my best guess.

Packet loss can be shown using the tab on the right hand side of the driver station window.

We’ll take a look, thanks.

(At the moment our code barfed and we can’t get it to deploy, so one problem at a time…)

We’re having serious COM issues—dropping packets like crazy all the time, with the COM light on the DS half green and half red—and we don’t know why. The solenoids firing correspond to spikes in latency, but sometimes we’re getting the latency without the pneumatic wonkiness.

We’ve replaced the radio, added a USB wifi adapter to the laptop (which helped but did not solve the problem; the picture shown is after all mentioned remedies), power cycled both the computer and the robot.

Suggestions welcome.

Well, half red and half green usually means that you’re only getting packets from UDP or TCP but not both. You can look at the network status page of driver station to see which.

We’ve never used a Rev hub, is it CAN-based? What does the CAN utilization look like as this is all happening?

We swapped out the driver station computer and all Ethernet cables and, at least for now, the problem hasn’t repeated.

Are you using single solenoids? A single solenoid that is set will retract when disabled, but a double solenoid will keep it’s position.

Double, 24V.

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