Hi I have a Beaglebone RA5 - its always been pretty funny about taking power through the barrel adapter- now this morning it refuses to boot up alltogether-
When I connect it via usb to my computer or to any usb adapter the green light next to the barrel flashes one time - then nothing happens.
Can anyone give me tips on what to look for in diagnosing the problem?
I am designing a product that uses the bone. this issue worry's me as power can fail at any time
would a few large caps on the 5 volt line take care of this ?
I have designed in 1 820uF cap already.
i can add as many as is needed to keep the power up long enough for a orderly shutdown.
This is working theory at this point. It only happens on a very few boards that we have seen, less than .001 percent. There may have been some changes made in later revisions silicon that might be related to this as we have not seen this issue on the boards using the newer silicon But all we have is the current revision of silicon. The other problem we have is that everyone reporting this says all they did was plug it in. We can’t be 100% sure that it was not an issue with wires being connected to I/O pins on power up, which violates the power up sequence…
You should be able to add a larger cap to the SYS_5V rail and solve this issue,depending on the load of the rest of your board. It is easy to check, just look at the power down pattern of the rails and make sure they are in spec. Holding the reset button does this, so that is why we posted it as a work around.
Should there be mention of preferred and proper shutdown methods in the SRM? I don’t remember seeing anything about this prior and especially with no or limited console access at times I can say I’m guilty of simply removing power without even thinking about the reset button more than once. thankfully the board (v3) still works fine. (if any further data might be useful like /proc/cpu or cpuinfo let me know I can send it along.)
It is on my list. In the mean time read the WIKI. It is much shorter.
thanks for the response- as well as the links, definitely sounds like the case.
Any insight regarding power supply/management in the upcoming beaglebone? Im hoping there are some improvements on it…
Same basic design. I added a push button power switch, as we now should have RTC working. This allows for the proper shutdown and if supported in SW, can prevent SD card corruptions and allow to go into sleep modes instead of just going to power off. So, the best way is to push the power button to power off. To date we have not seen any of this type of issues in the new version.