PD blinking yellow lights

[SMAbotics]

We're entering our second season in 2016- in the off season have built an experimental (roboRIO) robot, learning systems we didn't get in 2015 (mecanum drive, pneumatics, PID). The robot is built, have mecanum working, working on pneumatics, PID next. We have an issue we don't know how to resolve. The PD board has blinking yellow lights. We've cleared all sticky faults, still have blinking yellow lights. Not sure where to go from here. Advice?

[EmileH]

Log into the RoboRIO's Web dashboard (for your team it should be http://roborio-5493.local/). When the list of all the connected CAN devices appears, click on the PDP in the list, and in the header bar near the top of the page, click "Self-Test", and it will give a readout of the PDP data. More info on the webdash can be found here: http://wpilib.screenstepslive.com/s/...anual-id=13503

[Mark McLeod]

Double check your battery voltage before clearing the PD fault.
The yellow is a sticky fault most commonly meaning that a low battery fault occurred sometime in the past.

[SMAbotics]

Thanks for the replies. We've gone into the Web Dashboard, looked at the PDP, run the self test. Under sticky faults it gives "0000000000000"- which I believe indicates its fine (?). Am I wrong?

[SMAbotics]

We replaced the battery with a newly charged battery. Do the PDP blinking yellow lights auto-correct if low voltage has occurred once a fresh battery is put in? Or, is there something we have to do to correct it?

[ozrien]

Orange means a sticky fault is set. I'm guessing StickyFaultVbus is '1'. It might be easier to just post the screenshot of the self-test.

Assuming it's the vbus fault, this means that the PDP saw battery voltage below 6.5V once. Anytime it sees a low vbus, the sticky fault is set and can be cleared through web interface. Be sure to check battery voltage reported in the PDP before clearing the fault to ensure it the problem is resolved.

Check out section 5.1 in PDP's User Manual.
http://www.ctr-electronics.com/contr...ical_resources

[ozrien]

Good screenshot of clearing the sticky faults under (for PCM but its the same procedure)....

http://wpilib.screenstepslive.com/s/...ribution-panel

...search for "Clearing Sticky Faults". Be sure that the "Clear Sticky Faults" text actually displays.

[SMAbotics]

Thanks Omar. We'll take a look at sticky faults again this morning. We ran the drive base hard, til it intermittently responded to joystick input. At that point, the Driver Station indicated a battery voltage of ~ 10V (I guess its possible it dipped below 6.5v ?). We turned it off, replaced the battery, went home for the night. Next day we discovered blinking yellow lights.

[ozrien]

If the "resting" battery voltage was as low as 10V, then under load (direction changes or transitions from not-moving-to-moving) the voltage could get that low. Also the roboRIO Driver Station may enter "Brown Out", meaning actuators are disabled to keep the roboRIO running.

https://wpilib.screenstepslive.com/s...anual-id=24166

This is a good opportunity to learn about the Driver Station logger. Take a quick look at the DS logs of last night you can see how low the battery voltage got. Learning how to use the viewer will come in handy at some point in the future if your robot ever misbehaves during a match and you need to figure out why.

https://wpilib.screenstepslive.com/s...og-file-viewer

[SMAbotics]

Omar, I'm attaching two screenshots from the Driver Station Log File Viewer. Yowsa. Lots of brownouts. Voltage dips below 6.5V, many times. This is very informational- can you take a look and let me know what you think.

[ozrien]

Hah yeah Yowsa. Was the battery just depleted? I mean a single charged battery won't last all day (or even several matches).

If the battery wasn't charged then its a no brainer.

If it was charged then maybe Battery-Beak it to see if the battery has higher-than-normal battery-resistance (basically a bad battery).

If the battery itself is ok, inspect all the contact points from the battery to to the 120A breaker, and then into the PDP. Tighten the nuts on the 120A breaker if they are loose.

Does that happen with all batteries, some batteries, or just that one?

Also try not to run down FRC batteries to that point. It reduces the life of the battery, and batteries aren't cheap

[SMAbotics]

Everyone was just WAY EXCITED driving mecanum for the first time- having built it and programmed it. Probably would have continued driving it till it totally crumped.... We'll check the battery. Thanks for your guidance, have more to consider now- very helpful. BTW, sticky faults have been cleared (webdash- self test).