Over the years we have toasted a few digital sidecars by getting metal shavings into them. We try to be careful when drilling and fastening things to the robot, but inevitably some debris manage to find their way into the exposed terminals and then things go haywire. It would seem that the roboRIO will also be susceptible to ingress of small bits of robot.
Are there any electrical protections built into the roboRIO that will prevent bad things from happening if this occurs?
Have beta teams noticed any issues?
What have teams done in the past to safeguard against this? We have talked about mounting the roboRIO vertically, or adding shields or covers, etc.
The roborio is protected against shorts between any of it’s external pins. We tested it and were unable to damage the RoboRio by intentionally shorting any of the pins together. Offhand, I don’t recall the voltage they’re protected up to, but it’s well above the 24V we have on the robot.
The roboRIO is a lot more robust than the digital sidecar. The roboRIO is designed to survive an (inadvertent) shorting of any pin to any other pin and/or the (inadvertent) application of battery voltage to any pin. Plenty of teams are concerned about toasting their $430 roboRIOs as opposed to the $70 sidecar, but I’ve seen nothing to indicate this is a significant concern.
That said, it would seem prudent to mount the roboRIO behind a piece of Lexan to protect it from impacts in addition to swarf. (As well as to protect any MXP electronics that haven’t undergone the amount of engineering that went into the roboRIO.)
I’ve only had a few minutes with a roboRIO, and from what I’ve seen, a simple shield on top of it should prevent aluminum shavings from getting in. The DSC was fairly resistant to outside shorts, but little aluminum shavings on the inside caused some magic smoke to leak out… I’d be worried about inside shorts if it doesn’t have a coating on it.
Our cRIO somehow ended up with an incredible amount of aluminum shavings inside of it, causing crashes/random behavior and errors. Amazingly, after cleaning it out, it worked perfectly.
The RoboRIO is supposed to be protected against having the battery shorted to any pin on it. This includes the USB ports. (We haven’t tested it since we still had other beta testing to perform). The only pins you could short to and possibly have an issue are supposed to be the ground pins, in which either an internal fuse or the wire you are using to short will vaporize. In the event it’s the fuse, NI can repair it for you.
The roboRIO is conformally coated. In addition, the internal power rails are monitored and current limited. If the rails are shorted, the DS will log an error message, increment a counter on the power tab, and the power LED on the roboRIO will indicate the failure. If this happens, you should try to clear the short to restore correct operation.
I encourage teams to observe good practices and try to keep debris, metallic and otherwise, from falling into electronics. But to answer the OP, failures of the digital breakout board should not necessarily predict failures of the roboRIO.
If anyone does experience a failure, please contact NI so that it can be investigated fully.
The best way to protect your oRIO’s is to make sure nobody brings any milk to the team meetings. As well as to make it clear that if anyone eats the oRIO they will have to replace it.