BeagleBoard XM PSU

I currently have an original BeagleBoard & I’m upgrading to the BeagleBoard XM over the next few days.
Can anyone tell me where to buy a suitable PSU to avoid using a powered USB hub?

I’ve been using this one with no problems whatsoever for almost a year now on my xM:

http://www.maplin.co.uk/ac-dc-multi-voltage-4a-switched-mode-power-supply-48517]link

to avoid using a powered USB hub

Make sure you have some slim USB sticks or they may get wedged against each other in the on-board hub sockets, which are a little tight together.

Thanks Patric, that’s exactly what I was looking for!

Thanks Trevor, luckily I’m using an external Seagate USB HDD, it’s cable happens to be almost perfectly flat, so hopefully I’ll be ok!

(Next I really must learn how to quote peoples replies!)

to avoid using a powered USB hub

If you don’t use a powered hub, be aware that the hub and all the devices connected downstream of it must not consume more than 500 mA in total. That’s a pretty severe limitation.

I opted to put a BeagleBoard and a 7 port hub in the same case, and run them from the same power supply by wiring the 5 volts from the BeagleBoard to the hub.

If you don’t use a powered hub, be aware that the hub and all the devices connected downstream of it must not consume more than 500 mA in total. That’s a pretty severe limitation.

I think he’s talking about just using the xM’s built in hub, instead of connecting a (bus powered) external one. So as long as the power supply is up to scratch he should be able to get 500mA per port.

Yes I was just planning on using the ports on the xM, I only need Keyboard, Mouse & HDD.

I’m using just the ports on the xM, for keyboard, mouse and HDD. The HDD is a Freecom Classic 160GB. N.B. it is not a Freecom Classic II (the current model). I found that the Classic II required the kind of USB cable which uses up two sockets, whereas the original Freecom Classic just required one.

At least that was the case up until the Wakefield Show. When we got our BeagleBoard back home from the Wakefield Show we found that the drive continued to work in RISC OS fine being connected with just the one socket, but when trying to boot Ubuntu (which occupies the second half of the drive) it failed to boot up. We could cure this by using a two-plug cable, or by plugging the drive in via a powered hub.

I’d rather avoid the two-plug cable, but unfortunately when we have the powered hub connected to the BeagleBoard for some reason the ADSL router cannot hold its external connection for long: the DSL and internet lights keep dropping off and it then renegotiates. There’s something rather horrible electrically going on here, and as I only have a cheap digital multimeter and no electronics expertise I’m a bit stumped. We’re currently running the Freecom Classic 160GB with it occupying two USB sockets direct on the xM board, so with keyboard and mouse we have no spare USB sockets any more! Slightly irritating.

The puzzle is, what has changed? No operating system upgrade as far as I remember, so either the drive is changing its behaviour or the power supply is delivering differently. But who knows? I have no way of guessing how to diagnose the problem.

My only thought was

1. to buy a another USB powered hub to see if I can find one that doesn’t upset the ADSL router

2. buy a new ADSL router to see if I can find one that doesn’t get upset

3. buy a new power supply for the BeagleBoard and see if that makes a difference

4. seek recommendations for another low-power USB HDD so we can free up one USB socket again.

Any suggestions?!

The BB can be a bit picky about the amount of amps passing through the whole circuitry. Does the little red “overcharge” LED come on?
IIRC there’s something about it in the manual. Seem to remember you didn’t want to exceed 3.5A for BB and peripherals. If your HDD uses the full power available from USB 2.0 you’ll have to remember the way the on board hub has been designed: it’ll only support full power in total on each of the two hubs, not for each USB socket.

I decided not to make too much use of the on board connectors though, mainly to save them from wear. There’s the PS/2 adapter for the keyboard (not that necessary) and the small powered hub. Wired both the BB and the hub directly to the above mentioned Maplin’s PSU but each on a dedicated lead. Used a portable 80GB TrekStor 1.8" USB disk as HDD and while they’re slightly more expensive (well I already had one so decided to give it a try) and probably slower (not sure about that one though) they’ll run just fine on a single USB port. Mine’s directly connected to the little hub, so won’t put any load on the BB itself.

All I can say is: it’s been a total success so far (Dec 2010)
No worries