B+ USB 3G dongles OR USB Drive may trip brownout detector

[davidjb]

Just did a quick check on the net, and have learnt that the K3571-Z also has a small storage space. I just wonder if this can be the problem. Besides, no offence, do your B and B+ run exactly the same OS?

I'll try and disable the virtual CD functionality and see if that makes any difference. I'll report back!

The virtual CD functionality is already disabled (I'd done this a while back, I now remember), so it seems that isn't the problem. I have two of the same K-3571 USB dongle and both trip the brownout detector (when used separately) on the B+.

I'll try a different USB cable to power the Pi and see if that makes any difference. That said, if the exact same cable and power supply work with my model B, then surely this is pointing to a hardware change/fault in the B+ being the cause?

[superman]

Hmm... your B+ is probably ... sort of kaput ... and it may be the time to fill in the Returns Form. Frankly, doing a fresh installation for the B+ (rather than cloning the Raspbian from the B) would be my last-ditch attempt before sending it back if I was in your shoes.

Good luck,

[davidjb]

Cheers superman, thanks for the suggestion. I'll try a fresh install and with a different set of USB cables, just in case it happens to be that. If all else fails, I'll return it & try another. Will report back with any progress.

[Hove]

Unfortunately neither of these lines of code worked however now the USB drive is continually trying to start instead of starting and stopping. I increased the max_usb_current=1.2 but nothing changed. Any other ideas? Thanks in advance!

In /boot/config.txt add EXACTLY these lines:

Code: Select all

max_usb_current=1
safe_mode_gpio=4

max_use_current is a 0 or 1 NOT the maximum current you desire.

By adding both, you're covered regardless of the software / kernel / firmware you are using.

My B+ browned out when I attached a USB drive (as well as keyboard, mouse, and WiFi dongle). Made exactly the above change and it works perfectly now.

[Aydan]

Code: Select all

max_usb_current=1
safe_mode_gpio=4

My B+ browned out when I attached a USB drive (as well as keyboard, mouse, and WiFi dongle). Made exactly the above change and it works perfectly now.

If this fixed it, your problem wasn't primarily brown outs but USB current overload.
Brown out comes from a weak powersupply and/or thin cable. If your power indicator kept flashing and now it doesn't, that means that when the usb devices power up, your power supply drops below the brown out threshold before the USB power limit kicks in and the cycle starts again.
Still means your power supply is weak.

Regards
Aydan

[i8igmac]

i would like to share what i have found... i have 2 usb wifi dongles... after associated, some tcp data will pass threw but when it seems like to much the disconnect and reconnect happens (over-current)

was able to fix this from happening with one of the wifi dongles...
iwconfig wlan0 rate 5.5M fixed

it now holds a solid connection. each packet is a bit lighter then the default 54Mbps...

maybe not brown out related, But identical disconnect/reconnect symptoms... so maybe explore options for lightning the packet...


also, this did not make any difference for me /boot/config.txt
max_usb_current=1
safe_mode_gpio=4