4 ms·

Crazy things you can plug into your iPhone's audio jack

14 points by skram 13y ago

wehadfun 13y ago
What about card processor?
- skram 13y ago
  I don't think that's considered crazy anymore :)
csmuk 13y ago
These things all seem like risky hacks to me. It only takes a single "new minor revision" of the iPhone with slightly different electrical characteristics to scupper these devices. I'd rather pay through the nose and get something proper for the job. That goes for those POS card readers as well
- mattgreenrocks 13y ago
  Wouldn't that invalidate Square too? They sell those POS card readers in the Apple Store, I don't think they'd break them so quickly.
  - csmuk 13y ago
    Yes that would. Apple still have to follow global supply and demand even if they do a lot of demanding. If there was a shortage of an audio interface, DAC or filter IC then it's inevitable that an alternative will be sourced to avoid final product shortages which would impact the bottom line. These may or may not have the same specifications. To a human ear it may not matter but to a coupled circuit, it may be different. The 3.5mm audio jack is also an incredibly iffy electrical standard. There basically isn't a standard.
- ars 13y ago
  > with slightly different electrical characteristics Isn't it a microphone jack? Apple can't change that, or microphones won't work. These programs probably just send frequency tones while pretending to be a microphone. It's not very high bandwidth but it works well enough.
- bradleyland 13y ago
  Heh, if you think this is a risky hack, you'd be amazed at how we used to use the internet. Once upon a time, we used these things called modems that modulated an analog signal in such a way as to send digital communications down a wire that was designed as the technological equivalent of two tin cans attached to a string. It's a miracle any of it ever worked. Hell, it's a miracle any of this stuff works. Many of these devices are, essentially, modems. They modulate the analog signal in ways that are tolerant of the faults typical in analog systems. Fortunately, they've got two things going for them: 1) They're sending the analog signal over a very, very short distance. 2) Modulated communications are a very well developed field of signal transmission. They're hacks, but they're old, established hacks.
  - csmuk 13y ago
    It's not a miracle or a hack. Modems were sound bits of engineering and were based on international standards that allowed them to interoperate with each other properly. They had clearly defined electrical and protocol standards. They may use the principle of a modem but there is no established standard for communication. I assume that you know about impedance and loading based on the above? If the internal resistance of the current loop suddenly flies up or down, is the circuit on the other end going to perform to the same? Nope. There will be less current available for the device. At that point it will work intermittently or stop working all together. Your microphone or earphones will still work quite happily though.
    - bebna 13y ago
      But there are Standards. 2 to be exact: one from OMTP and one from CITA. The OMTP one, is even used as national standard in china: http://www.cspress.com.cn/u/cms/www/201208/17092831ounz.pdf http://www.cspress.com.cn/u/cms/www/201208/17092831ounz.pdf
jensnockert 13y ago
I helped build an EEG device that connected to the head-phone jack, not a real product though. Just a hackday project.
rch 13y ago
The 'iXR2012 Personal Radiation Meter' would be good for people that sometimes work with or handle materials from drilling wells, and the like. A friend of mine has a story about a particularly 'hot' sample sitting on a colleague's desk for weeks.
grandalf 13y ago
notable link to research: http://web.eecs.umich.edu/~prabal/projects/hijack/ http://web.eecs.umich.edu/~prabal/projects/hijack/
deleted 13y ago
[deleted]
mikeweiss 13y ago
Those last items (Starbucks latte) will do more damage then good. Those 3.5mm jacks are delicate and if you bump your latte into something it could break it.
awakeasleep 13y ago
Flagged blogspam listicle

14 points by skram 13y ago

wehadfun 13y ago

What about card processor?

skram 13y ago
I don't think that's considered crazy anymore :)

csmuk 13y ago

These things all seem like risky hacks to me. It only takes a single "new minor revision" of the iPhone with slightly different electrical characteristics to scupper these devices. I'd rather pay through the nose and get something proper for the job. That goes for those POS card readers as well

mattgreenrocks 13y ago
Wouldn't that invalidate Square too? They sell those POS card readers in the Apple Store, I don't think they'd break them so quickly.
- csmuk 13y ago
  Yes that would. Apple still have to follow global supply and demand even if they do a lot of demanding. If there was a shortage of an audio interface, DAC or filter IC then it's inevitable that an alternative will be sourced to avoid final product shortages which would impact the bottom line. These may or may not have the same specifications. To a human ear it may not matter but to a coupled circuit, it may be different. The 3.5mm audio jack is also an incredibly iffy electrical standard. There basically isn't a standard.
ars 13y ago
> with slightly different electrical characteristics Isn't it a microphone jack? Apple can't change that, or microphones won't work. These programs probably just send frequency tones while pretending to be a microphone. It's not very high bandwidth but it works well enough.
bradleyland 13y ago
Heh, if you think this is a risky hack, you'd be amazed at how we used to use the internet. Once upon a time, we used these things called modems that modulated an analog signal in such a way as to send digital communications down a wire that was designed as the technological equivalent of two tin cans attached to a string. It's a miracle any of it ever worked. Hell, it's a miracle any of this stuff works. Many of these devices are, essentially, modems. They modulate the analog signal in ways that are tolerant of the faults typical in analog systems. Fortunately, they've got two things going for them: 1) They're sending the analog signal over a very, very short distance. 2) Modulated communications are a very well developed field of signal transmission. They're hacks, but they're old, established hacks.
- csmuk 13y ago
  It's not a miracle or a hack. Modems were sound bits of engineering and were based on international standards that allowed them to interoperate with each other properly. They had clearly defined electrical and protocol standards. They may use the principle of a modem but there is no established standard for communication. I assume that you know about impedance and loading based on the above? If the internal resistance of the current loop suddenly flies up or down, is the circuit on the other end going to perform to the same? Nope. There will be less current available for the device. At that point it will work intermittently or stop working all together. Your microphone or earphones will still work quite happily though.
  - bebna 13y ago
    But there are Standards. 2 to be exact: one from OMTP and one from CITA. The OMTP one, is even used as national standard in china: http://www.cspress.com.cn/u/cms/www/201208/17092831ounz.pdf http://www.cspress.com.cn/u/cms/www/201208/17092831ounz.pdf

jensnockert 13y ago

I helped build an EEG device that connected to the head-phone jack, not a real product though. Just a hackday project.

rch 13y ago

The 'iXR2012 Personal Radiation Meter' would be good for people that sometimes work with or handle materials from drilling wells, and the like. A friend of mine has a story about a particularly 'hot' sample sitting on a colleague's desk for weeks.

grandalf 13y ago

notable link to research: http://web.eecs.umich.edu/~prabal/projects/hijack/ http://web.eecs.umich.edu/~prabal/projects/hijack/

deleted 13y ago

[deleted]

mikeweiss 13y ago

Those last items (Starbucks latte) will do more damage then good. Those 3.5mm jacks are delicate and if you bump your latte into something it could break it.

awakeasleep 13y ago

Flagged blogspam listicle