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Projects: hijack (Hijacking the iPhone earphone jack)

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21–30 of 41 posts

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#21
Pheh, they forgot the best application ever: iPhone-controlled vibrator:

http://www.ohmibod.com/bodyheat/

I was at a presentation by the app's creator, apparently the hardware was already available through some company, so you could theoretically do it with any device that outputs to a headphone jack. The iPhone's touch interface simply provided a ... unique and apparently (don't ask me!) expressive method of control.

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#22
post #3

Cool project! Currently, I am a bit doubtful concerning whether drawing extra power from an already very battery lifetime-constrained smartphone is a good idea. On the other hand, the batteries shold improve in the future, so with a bit of luck the idea may just as well come to maturity at the right time!

It doesn't drain the battery any more than listening to music does :) Really cool project!

Listening to music doesn't drive a constant 22 kHz tone.

[Edit] I really don't understand -- why was I downvoted here? Can someone explain why they think I'm wrong? Isn't a constant, high-frequency tone going to draw more power than variable output with significant larger gaps (and a likely lower peak voltage difference?)

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#23

Earlier quoted context omitted.

Apple wants you to use their 30 pin interface, but that requires going through their MFi program and that lets them control the hardware ecosystem like they do the software ecosystem. To be fair, there are certain advantages to hardware manufacturers willing to jump those hurdles. You're able to ensure no one can make software for your hardware, for one. Secondly users who plug in your hardware can automatically be t…

Is there anyplace online people in the MFi program hang out (forums, usenet, mail lists, etc.)? I've got some very basic questions about the whole process, but it seems like such a black hole (from the outside looking in). It would be great to use the ipods or ipads for industrial data collection, but we'll need IR and a way to get data on/off without network connectivity.

Not that I've seen, and the NDA you have to accept is pretty strict.

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#24

I think it's a very interesting project. I've been very interested in things that combine hardware with smart phones, since the Apple keynote that showed the first authorized hardware "extensions". (though since then, I've been disappointed in not seeing much of anything) However, can anyone chime in about the differences there are between using the iPhone jack and using the dock connector? I know you're supposed to…

You could create un-authorized hardware and apps using the 30 pin connector, but they would only run on jailbroken devices. There are places to buy knock-off (non-apple made) dock connectors so some people must do this.

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#25

Earlier quoted context omitted.

Is there anyplace online people in the MFi program hang out (forums, usenet, mail lists, etc.)? I've got some very basic questions about the whole process, but it seems like such a black hole (from the outside looking in). It would be great to use the ipods or ipads for industrial data collection, but we'll need IR and a way to get data on/off without network connectivity.

Not that I've seen, and the NDA you have to accept is pretty strict.

That's what I was afraid of. In the quantities we're looking at, maybe we'd be better off jailbreaking and selling the whole thing as a package.

Or maybe I'll just drag my feet a bit and hope there's a decent Android tablet with USB host and an SD slot coming soon...

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#26
post #3

Cool project! Currently, I am a bit doubtful concerning whether drawing extra power from an already very battery lifetime-constrained smartphone is a good idea. On the other hand, the batteries shold improve in the future, so with a bit of luck the idea may just as well come to maturity at the right time!

From their paper: "To estimate the impact of energy harvesting on the phone, we modifying an iPod Touch to measure battery current and voltage. We play an audio file that generates the required 22 kHz tone and find that the iPod draws 91 mA at 4.04 V when the harvester is attached and 37 mA at 4.04 V when the harvester is not attached. These figures illustrate the substantial inefficiency of this approach compared with d…

Speaking of figures, I wonder how this would compare to what can be gathered from ambient radiowaves with a device of a similar size.

I remember a posting from somewhere where Nokia claimed to reach in the miliwatt range only using ambient radiowaves. Can't seem to find it again though.

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#27

Earlier quoted context omitted.

Not that I've seen, and the NDA you have to accept is pretty strict.

That's what I was afraid of. In the quantities we're looking at, maybe we'd be better off jailbreaking and selling the whole thing as a package. Or maybe I'll just drag my feet a bit and hope there's a decent Android tablet with USB host and an SD slot coming soon...

You should take a look at Adam from Notion Ink. It's USB host. To me that's the killer feature, for this reason!

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#28
post #12

That's truly amazing what they're doing here. I'm sorry if this is an ignorant question, but wouldn't it make sense for there to be some kind of USB port or something that's actually designed for I/O on the iPhone? I mean, surely there'd be less power loss if the port was actually designed to power other low power devices. Especially if it could mean that you don't need as powerful of an external microcontroller for…

I really have no idea about the iPhone, but the iPad can be a USB host via the USB part of apple's camera connection kit.

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#29
post #7

Also check out the Southern Stars SkyWire. Apparently it's a true RS-232 I/O cable that plugs into the dock connector. They use it to drive telescopes, but apparently it's not limited to that. http://www.southernstars.com/products/skywire/index.html I've gotten as far as opening an input and output stream with it, but I haven't had time to dig up an RS-232 device to try talking back and forth.

Unless you have a jailbroken device, arbitrary apps you write won't be able to access that stream.

For a researcher who's both familiar and happy with Cocoa, I assume jailbreaking wouldn't be a big hurdle.

Hell, GNUStep was created just to port a single application!

Re: Projects: hijack (Hijacking the iPhone earphone jack)

#30

Earlier quoted context omitted.

That's what I was afraid of. In the quantities we're looking at, maybe we'd be better off jailbreaking and selling the whole thing as a package. Or maybe I'll just drag my feet a bit and hope there's a decent Android tablet with USB host and an SD slot coming soon...

You should take a look at Adam from Notion Ink. It's USB host. To me that's the killer feature, for this reason!

Thanks, that's an interesting device.
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