USB Device requires touch power with iOS4

I don't know under what circumstances this is happening, but a lot of people are seeing this now. I don't see it myself, but you're not alone, for whatever comfort that may be.

I have same problem, SanDisk 8-in-1 reader used to work but now get the too much power message.

In other forums they mentioned there were changes made to power restrictions, which is why you're seeing a 'it's drawing too much power' alert. You can probably resolve it with a USB hub.
Here is 1 KB that has more information:
http://support.apple.com/kb/HT4106

Have you tried just plugging in your SD card itself and importing that way?

I think because the OP is using compact flash and not SD. Some cameras still use CF or Compact Flash cards.

SD is a newer standard and requires less power, but when you spend 2-4K on a DSLR, you don't toss it just because it uses CF vs SD.

As for a CF reader that will work with the iPad, I do not know of one.

You might be able to directly connect the camera itself via the connector and transfer the images that way.

My camera connection kit used to work ok on os 3.2.2. After upgrading to OS 4.2.1, both the SD card and USB connector do not work. They always display following message when I plug my SD card or Camera

Cannot Use Device. The connected USB device requires too much power

Don't know what to do now.

Same here, used to transfer from CF using sandisk reader and usb adapter to ipad. But now after upgrading to iOS 4.2 , it shows error message of using to much power...
Need a solving answer...

Just discovered I have the exact same problem, always worked with 3.2.2, but since 4.2.1 I get the USB uses too much power message when I connect my Sandisk CF reader. Very annoying, as this was one of the main purposes I used my iPad for.

Using iOS 4.2.1 and CCK

I have a USB hub with external power adapter.
I am able to connect it to the ipad with the USB camera adapter, plug in the power adapter and attach my external card reader to it and read my CF cards with no problem.

USB Memory sticks are a different problem. Some are just not recognized. Those that are, work fine.

In 4.2.1 the rules have changed:
1. The card or stick must have a directory named DCIM (same as 3.2.2)
2. There must be a sub-directory under DCIM... with an 8 character name with no spaces...
i.e., 100LEICA, 100NIKON etc.
3. The image files must be in the sub-directory. The file names must have 8 characters and no spaces
i.e/, L0000123.jpg, _PAS0123.jpg, NIK_0001.jpg, etc.


Hope this helps.

digidesigner wrote:
I have a USB compact flash card reader (SanDisk) that I used to download photo to my iPad. Now after the update it says it requires too much power. Anybody else having problems. Is it my reader or is it now going to be impossible to download from Compact Flash?

The iPad was never meant to be used to power external devices such as your card reader and never mentioned any such devices as being supported. Nevertheless, 3.2.2 set the power limit at the dock/USB interface at, I believe, 100 mA (or mW, can't recall which . .), which was enough to power some devices at least up to the size of some USB keyboards. In other words, the power draw is what sets the limit, not whatever might be connected in.

Of course, use of those things can seriously affect battery life, and 4.2.2 was bringing in some other new features that themselves would be adding power loading. So, the limit on the 'port' was dropped back down to about 20 mA, leading to the messages you're now seeing.

There's still a workaround of sorts. Get yourself a powered USB hub, get a USB extender cable (A to A), plug that cable between the CCK and the hub, plug the CF reader in to the hub also, and it should all work.

Well, a warning certainly would be in order, though I don't agree that these devices should be banned.

Reducing the power of the USB *without noticing about it upfront* is a very bad decision. As it stands, 4.2 delivers a number of feature losses without warning the users about it:
- Reduction of USB power
- Redefinition of rotation lock
- Loss of characters in at least the German keyboard - try to write Café or Citroën...

Klaus Busse wrote:
Well, a warning certainly would be in order, though I don't agree that these devices should be banned.

Reducing the power of the USB *without noticing about it upfront* is a very bad decision. As it stands, 4.2 delivers a number of feature losses without warning the users about it:
- Reduction of USB power
- Redefinition of rotation lock
- Loss of characters in at least the German keyboard - try to write Café or Citroën...

Strange take on things, Klaus. Providing 'USB power' was never an advertised feature to begin with; the fact that you could use your iPad in an un-supported, unofficial way in the past does not at all mean that you will always be able to, and no warning is owed to you if that occurs. The 'redefinition' was not only rather fully discussed before the new iOS was released, it is exactly in line with what that switch was always intended to be as described before the iPad was first released.

As for changes to the German keyboard, and perhaps others, that sounds like a valid complaint which should be addressed via the iPad Feedback Form: http://www.apple.com/feedback/ipad.html

Same here, the Ipad worked fine with my Sandisk card reader, now after the update it no longer works and gives the same 'cannot use device' message. Any great reasons for this?

Sparkioboi wrote:
Same here, the Ipad worked fine with my Sandisk card reader, now after the update it no longer works and gives the same 'cannot use device' message. Any great reasons for this?

Yes.

Scroll up.

This is a major hassle.
I'm supposed to bring a powered hub along now too?

I used a micro SD with a reader on the old OS with no issues, not it won't work.
It also won't work connected to the camera (same message, too much power).

I have used a card reader I have with CF, but a buddy with an identical one - it won't work.

I think Apple needs to fix this. What point it limiting the power anyway? So what if the battery goes down faster- it goes down faster with wifi turned on too, will they take that away also?

Stupid decision I say. Warn the battery will be depleted quicker? Sure no problem. But let us use the darn thing.