Den tisdagen den 19:e november 2013 kl. 02:00:55 UTC+1 skrev James Littlefield: > New to BBB but experienced with embedded systems. > > I'm working on a project using the BBB. Supplying +5V (up to 3A) directly > to the pins on P9 from a quality bench supply. I've found that briefly > switching the +5V supply OFF and then back on can pretty reliably leave the > BBB in an odd state characterized by... > a) No LEDs on > b) Very little current drawn from supply (10mA or less) > c) +5 present on P9.5 and P9.6 > d) 0.687V on P9.7 and P9.8 ( should be SYS_5V ). > e) P9.9 = 3.57V > f) P9.10 = 0V > > > I've found that once the system is in this mode no amount of pressing/holding > the momentary BBB pushbuttons will get the system working again. Removing > input power, waiting 10 sec or so, then restoring power will get things > working again. > > > Has anyone else seen this? It seems sort of like an issue with the > TPS65217C chip but I've not found any reported errata on that part. > > > Thanks > Jim
Then you should be aware of brownout. If the voltage goes below operating level you must recover by making sure that the voltage goes below a threshold which is application dependant. It could be below 100 mV. Only very advanced circuits will recover from brownout in a desirable way. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
