Today we have been working through a lot of issues with brownouts. We will brown out when we hit something too hard. We have a 6-cim west coast drive with a 1/8 in drop center and omni wheels on the front to help with turning. We are using Vexpro 3-cim ballshifters, with a low speed of 8-ft per second and a high speed of 18-ft per second. We have tried current limiting with the Talon SRXs and it doesn’t seem to be helping. How could we help prevent this or further diagnose the problem? Right now we are just planning to unplug a motor from each side.
You could try reading through the other ‘brown out’ thread on the CD frontpage?
This sounds like your radio is losing power as the barrel jack looses connection momentarily as a result of the acceleration. Best solution is to attempt to secure it better, or use power over Ethernet. There are many, many threads to be found on solutions to this issue ::rtm::
If your losing power on impacts, odds are it’s the result of your roborio and/or radio losing power due to a bad connection somewhere as opposed to excessive current draw from your drive. Check you driver station logs to get a better idea of the circumstances that lead to this (to see if it’s your rio or radio that’s rebooting). If it’s your rio, check all your power wiring leading into the rio (from the battery terminals to the main breaker to the PDP to the rio).
Per the other threads, I suggest doing a “pull test” on all of your connections to make sure non of them are loose or anything. Good luck!
Also make sure that all connections made with screws or nuts and bolts (i.e. on your breaker, PDP input and some motor controllers) are tight. You should not be able to make them turn using your fingers.
All good advice.
I just wanted to ask a clarifying question. Was this a brownout or a blackout/reboot?
A brownout doesn’t involve anything rebooting. The brownout is typically a 100 or 200 ms gap in ability to drive because the roboRIO went into brownout in order to prevent a reboot of important system components.
So if you are getting a brownout after a hit, it is more likely current related. If you are rebooting something after a hit, it is more likely a loose wire or possibly a short of exposed wiring.
As mentioned, the log files will help you determine which thing occurred. If you want to post the file or a screenshot, we can help you look at it.
Greg McKaskle
Check that the 6ga wires going into the main breaker are tight tight tight. That is the main problem I am finding on the field for radio/Rio reboots, not the barrel connector (same as last year when it was scapegoated then as well). Teams tend to forget that there are two big connections under that ball of electrical tape they use for insulation when told to check all connections from battery to Rio. One robot this weekend had them so loose that one was floating so that no contact was made at all with the result of the bot not turning on on the field. Quickly tightened it for the match and instructed them to check ALL of the connections before the next match.
The only actual barrel connection problem i have found through 7 Regionals and 2 off season events with this radio combination was one that looked like it was put in a blender before being put on the robot. Every other on field reboot I could trace to a faulty electrical connection somewhere else with very little searching, with an admittedly unscientific guess of 75%+ being the main breaker connections