Comments on: Boom!

By: Luke

Luke — Wed, 26 Sep 2012 15:16:05 +0000

@peter: “Secondly, USB 2.0 is fast enough to handle all the use cases needed whether it be transferring data or communicating with an accessory.” Since when did we become ok with “fast enough”? Are you saying you aren’t interested in being able to transfer 5 songs with USB3 in the same time it took you to transfer 1 song with USB 2.0?

By: Rainer Brockerhoff

Rainer Brockerhoff — Thu, 20 Sep 2012 00:50:19 +0000

@peter: most of these arguments are also addressed in my follow-up post, which you may not have seen yet. If you, or any other commenter, wish to continue the topic there, please feel free to do so; I have closed further comments here to allow for a more orderly discussion.

By: peter

peter — Thu, 20 Sep 2012 00:34:22 +0000

Firstly Micro USB connectors can safely conduct 1.8A. MANY tablet manufacturers ship their tablets with 5V 2A AC/DCs that output to micro USB.
Apple could have easily allowed the iPad to charge off 1.8A supplies. It would just take a bit longer but I think people would accept a 10% drop in charge current for the flexibility and convenience of not having to carry out a freaking proprietary Apple connector. PLUS, there’s a new micro USB spec which allows 12V charging over existing micro USB connectors. So bye bye power limitation problems:)

Secondly, USB 2.0 is fast enough to handle all the use cases needed whether it be transferring data or communicating with an accessory.

Thirdly, if Apple did this because they want to reduce the intelligence required in an accessory device they could have simply used resistors between D+/D- to denote different accessories, button presses, etc.

Finally, if Apple had gone with micro USB then they could also have gone with the standard USB OTG hosting method which would allow the phone to power accessories such as mice, keyboards, etc.

Bottom line is that micro USB is very flexible and could handle the entire use case that Apple would like to provide.

By: Rainer Brockerhoff

Rainer Brockerhoff — Wed, 19 Sep 2012 11:37:35 +0000

@someone: thanks for the catch on the 1.8A standard. Confusingly, many manufacturers (here's one datasheet I actually had on file) specify only 1A. "one might argue that even the 2A of the current charger is too low" Indeed, upcoming battery technology will allow even faster charging. And Apple's old 30pin-to-micro USB adapter doesn't list the iPad among compatible devices.

By: someone

someone — Wed, 19 Sep 2012 07:28:29 +0000

“@someone: true, some connectors now allow 1.8A (still not quite enough for the 2A iPad). But this has to be valid on both the cable and the plug side. So many commenters are using (or want to use) cheap cables that certainly wouldn’t support that.”

Actually, the micro-USB connector standard specifies 1.8A [1] (minimum) (for pins 1&5). So many commenters will actually be using 1.8A spec cables no matter what they want.

(Also, in sleep mode even the new Ipad charges from USB1 port. And USB2 connected to computer (0.5A) can generally at least keep the battery level steady. So it is not exactly ‘the 2A iPad’, although one might argue that even the 2A of the current charger is too low.)

[1] Micro-USB Cables and Connectors Specification Revision 1.01 as of April 4, 2007

By: Rainer Brockerhoff

Rainer Brockerhoff — Tue, 18 Sep 2012 22:00:15 +0000

@someone: true, some connectors now allow 1.8A (still not quite enough for the 2A iPad). But this has to be valid on both the cable and the plug side. So many commenters are using (or want to use) cheap cables that certainly wouldn’t support that.
iOS currently has very limited support for USB devices, in fact a wired keyboard and connecting a camera (or its SD card) are the only ones I can think of, offhand, outside “charging and syncing”.

By: someone

someone — Tue, 18 Sep 2012 20:36:00 +0000

“Two pins (or even one!) can in theory transfer anything, true.” And outside theory quite many things have been standardized:
http://www.usb.org/developers/devclass_docs

“if you look at current plug manufacturer’s specifications the usual limit is 0.9A per pin” Well yes… Since that is enough for most things. If you were to create a popular device that requires more power you probably could perhaps order some more robust ones? (And a quick search finds at least 1.8A connectors… for example MUE44-5G7700)

“so most of the dock connector functions wouldn’t work – only charging and syncing would”

I still find this statement a curious one. I mean, you can connect for example a mouse to a Symbian phone, why would iOS limit the connector to only syncing?

By: Rainer Brockerhoff

Rainer Brockerhoff — Tue, 18 Sep 2012 19:45:19 +0000

@someone: “Products expected towards the end of 2012″ – a little late, perhaps. At this moment I couldn’t find more technical details, but if you look at current plug manufacturer’s specifications the usual limit is 0.9A per pin. Some even less. Switching pins to work in parallel is the obvious solution, one which I’m sure Lightning will also use.
Two pins (or even one!) can in theory transfer anything, true. Having several pins avoids negotiation and interference – Thunderbolt, for instance, has two 4-pin high-speed channels and one 2-pin low-speed channel.

By: someone

someone — Tue, 18 Sep 2012 19:24:49 +0000

Something to consider regarding “Also, the pins are so small that no current plug/connector manufacturer allows the 2A needed for iPad charging.”

http://www.usb.org/developers/powerdelivery/PD_1.0_Introduction.pdf

I’m also curious: What exactly is it that can’t be negotiated and transferred with 2 pins of data?

By: Austinchief

Austinchief — Tue, 18 Sep 2012 02:55:54 +0000

@Ranier
But you still fail to address how my post proves your assertion that a usb connection wouldn’t be adequate due to either pin count or charging reqs. Both of those assertions are false. Apple could have used a USB3 connector without any loss of functionality(unless you are just THAT enamored with the idea that the plug is reversible). fact is, this was a move to stay proprietary simply for the sake of staying proprietary. I have yet to see ONE solid technical justification for it.

By: Dave

Dave — Mon, 17 Sep 2012 19:31:44 +0000

This is all about “locking you in” to their model of themselves. Recently I purchased a very expensive “HI-Fi” system that has one of the old Apple plugs. No use anymore… and this cost over £1k just for the AV amp with the connection.

Don’t think I’ll be buying any more devices from Apple.

By: Neil

Neil — Mon, 17 Sep 2012 14:53:09 +0000

There was not really anything wrong with the old connector.

The “it’s too big, and allows more stuff to be packed in the phone” is a smokescreen, and was never really substantiated anywhere.

Also, I don’t like the idea of a new iPhone or iPod touch wobbling around on a speaker dock connector adapter 2-3 cm up in the air – not very stable – meaning your speaker dock is effectively junk and needs replaced.