Pandaboard PSU

Hi,

Anyone know if you can run a Pandaboard (or indeed Beagleboard since they have similar requirements) from a 5V 2A supply? I can see the recommendation is 5V 4A (with DigiKey’s PSU being recommended); but others seem to drop down to 2A (I note CJEs use 2.5A).

In terms of USB draw the USB connections would be keyboard, mouse and possibly either a USB memory stick or USB SD interface.

I’m currently using a somewhat noisy 5V 4A (probably got transformer whine as it makes a high pitched buzz) which works fine but is unpleasant to have around. I’ve found a nice Pi bundle with an extra Pi, X100 and 5V 2A supply – it would be nice if that also worked on the Pandaboard as the two boxes are then interchangeable. But I am wary that instability is usually the principle sign of issues.

Anyone know if you can run a Pandaboard (or indeed Beagleboard since they have similar requirements) from a 5V 2A supply?

My Panda works with a 5v 2A supply, but I rarely have anything plugged into it other than a monitor in HDMI, a wireless keyboard/mouse nano dongle and an ethernet cable. I occasionally plug in a USB memory stick, but not often and not for long.

So does my Beagleboard xM, with a similar setup.

Anyone know if you can run a Pandaboard (or indeed Beagleboard since they have similar requirements) from a 5V 2A supply? I can see the recommendation is 5V 4A (with DigiKey’s PSU being recommended); but others seem to drop down to 2A (I note CJEs use 2.5A).

Four amps?!?

My xM runs quite happily from a iomega Zip power brick. It is a strictly regulated 5V supply – as I discovered when trying to use my drive off a battery setup – I had to use three D-cell NiCads (1.2V) plus one alkaline (1.4V) to get it to exactly 5V, because the voltage affects the spindle speed. I’ll leave it to you to shake your head in despair.

The power brick claims “5V DC 800mA”. I think it can actually deliver a little more than 800mA, but the xM is happy. Runs, also: keyboard, mouse, and one or two small USB sticks (one is the boot disc). May occasionally run a MIDI dongle. But, all in, nothing ‘consuming’.
All of my other 5V power supplies (inc. mobile chargers claiming to be 1A), failed to get the xM to complete its boot. An upsetting number of older 5V power bricks are anything but. Thankfully I probe before plugging in, and it “might” be okay to hook up to an 11V supply that will sink to 5V under load. But, you know, I rather equate that to overtaking at excess speed on a blind bend on a hill on a foggy rainy night. It “might” be okay, but then again, it might not.

This is part¹ of why I do most of my dev work on the Pi right now. I’m running that, and the HDMI→VGA, off two of the USB ports on my netbook. ;-) Don’t have to fiddle around with PSUs and extension leads…

¹ [And the other part is that I still don’t have a reliable MDF that the HDMI→VGA dongle likes, so booting the xM and getting some sort of display is still a bit hit’n’miss. In this vide grenier season, I’ll have to keep my eyes open for a DVI-compatible monitor.]

One option since you’ll probably have problem with some USB devices (and a 200A power supply will not correct this problem) is to opt for a 2A power supply for the motherboard and small USB powered hub (D-Link for example). So 2+2 :)

[remove me]

We supply a 2.5Amp unit as that was what used to be recommended, though 2Amp should be enough according to:
http://www.omappedia.com/wiki/PandaBoard_Accessories_%26_Peripherals

Power supply
The PandaBoard needs a 5Vdc power supply:
The official PandBoard.org accessories page recommends the Digi-Key T951-P5P-ND (5V/4A). However, that part is now obsolete. The new part as of 15 April 2011 is: Digi-Key 993-1019-ND. The power cord is a separate part. For example, the 3-prong cord for North America is: Digi-Key 993-1039-ND.
Caution (from the System Reference Manual): Only use a 5Vdc regulated power supply to power the PandaBoard. Connecting a supply with an output higher than +5Vdc could cause possible board damage.
Is 4A really necessary? This depends on the configuration you use, mainly how you supply the attached USB devices. If you intend to fully load the USB ports, yes you need a 4A power supply. But with all USB devices on a powered hub the PandaBoard uses e.g. 560mA @ 5V. So a 1.5A supply should be OK as long as you don’t load up on directly connected USB devices.
The plug packs which come with USB hubs are usually rated 5V 2A. They are fine subject to limitations as above.

IIRC last time we ordered some PSUs, 2Amp PSUs were more expensive than 2.5Amp units!

I’m sceptical about the 560mA, we did try powering a PandaBoard from a Lapdock and it didn’t work, but it will quite happily powers a Pi.

Rick: do you use a CRT or a VGA panel? If the latter and it will give you an EDID, you can test ScreenModes for me if you want. I presume your email address is on your site?

do you use a CRT or a VGA panel?

IISonic IIMJ7 flat panel display – 1280×1024.

If the latter and it will give you an EDID

It looks like a tiny microcontroller inside the HDMI dongle is wired to the IIC pins of the VGA connector, so there’s a chance this’ll work.

you can test ScreenModes for me if you want

Sure.

I presume your email address is on your site?

http://www.heyrick.co.uk/blog/index.php

Top of the page, just under the title banner thingy.

[Just noticed my site main index was last updated 2010 – eeek!

I wonder if my robots.txt still has those phantom entries to log disbehaving search engines? I really ought to dust off the cobwebs. Maybe when I’ve finished with doramax264.com (^_^) ]