Can someone tell me how this works? How does it send data over the headphone jack?

The sound of hands rubbing.

Ding Dong ding ding ding ding ding
4digits, up the slot, suddenly you're emptying

>youre poor faggot

Well, how it works is this but the question is what the fuck is it? Looks like a horrid monstrosity. I assume it's possibly some sort of security system, but why, what, where, who?

youtu.be/HN3qR2H4jGY?t=55s

>his credit card doesn't play "we're in the money"
>laughs in richfag

it's a card reader for smartphones

That's the level of abstraction Jow Forums can get to. Top kek.

A headphone jack is just a connector. You can put any signals you want over it. Doesn't have to be audio. Maybe not really high frequency RF or digital signals since they use very specialized connectors that would require you to understand transmission line theory to explain why but for simple low speed signals you can use whatever the fuck you want.

Why would you need that?

when you sell something and want to take payment with a credit card. have you really never encountered these?

You mean in real life, selling things on the streets or something? No, I haven't done that.

card swipe that connects to your phone

It plays the sound of money draining from your bank account through the microphone input.

Just a guess
>card has a magnetic stripe
>swipe card
>reader has electromagnet
>electromagnet creates a voltage across the jack
>app listens to jack as a mic and reads the signal
>processes signal like any card reader
probably nothing more complicated than that

small businesses might use payment systems that work with an iPad. Clamp one down to the register and connect a card reader and you're done, no need to set up a card reader from scratch, connect it to a PC, etc.

>small businesses might use payment systems that work with an iPad. Clamp one down to the register and connect a card reader and you're done, no need to set up a card reader from scratch, connect it to a PC, etc.
Fine I guess, but a bit shady.

Don't you mean...Slim Shady?

It's commonly used by very small retail to provide a card reader, tied into a specific bank or other service's mobile app. Neat way to drop the barrier for entry and leverage everybody's pocket supercomputers really.

Precisely.

Attached: Rich_money2.gif (510x304, 1.7M)

It sends the card info to your phone, genius.

youtube.com/watch?v=ULeDlxa3gyc

Is this a serious question, or are you just asking so you can laugh at retards, and trollphysics/trollscience? I really don't want to invest the time in giving you an actual answer if you already know and you're just asking for a laugh

lol'd

More like shim shady.

Not OP but I am genuinely interested. It should be able to intercept frequencies as well as broadcast them right?

Based 3.5mm perihperals.

Zoomers brainfucked.

Attached: fm-transmitter.jpg (474x474, 11K)

*dabs on your polled BUS interface*

Attached: 3.5mm-camera.jpg (777x437, 26K)

applels hate peripherals.

Attached: db9-3.5mm.jpg (300x300, 9K)

>he doesn't have a camera shutter flash that adds depth

OOOOOOF

Attached: 3.5mm-lamp.jpg (500x500, 25K)

*blocks your headphones path*

Hello, I am a superior output for your speakers.

Attached: 3.5mm-stereo.jpg (300x300, 9K)

>android allows pic relatred to be a programmable button
>applel removes home button and 3.5mm

Nothin' personal kid.

Attached: 3.5mm-button.jpg (500x500, 19K)

>sorry my phone doesn't work well in the dark

*blocks your path*

Attached: 3.5mm-jack_led_light_camera.jpg (300x300, 11K)

niiicceeeeee

yes welcome to the tech industry's main concern in 2009

Attached: tile-reader-chip.jpg (640x640, 12K)

kek

Attached: 1560514075049.jpg (852x616, 77K)

Pic related +
f-droid.org/en/packages/fm.a2d.sf/
= real FM radio

Attached: 3.5-mm-antenna.jpg (300x300, 4K)

>his phone doesn't have IR transmitter

Oh no prob.
Wait you do have 3.5mm jack though right.....?

Attached: infrared-jack.jpg (800x800, 41K)

IIRC the add-on itself has no ADC, it feeds the signal read from the magnetic head directly to audio-in.

If I use the 3.5mm port for the antenna, where do I plug the headphones?

Converts the data received from the card to audio, which gets sent to the phone where the PayPal app converts that audio back to data

In older cell phones there was a radio but no place for an antenna so it used the headphone's ground wire (i think) as the antenna, but sometimes you just want to use the speakers so this became a thing

>*Sales over $500 in a 7-day period made with the Mobile Card Reader are subject to an automatic 30-day reserve where funds are held in your PayPal account to cover the high risk associated with these types of transactions.

Quit kvetching and buy it goy!!

Attached: 1560613461196.jpg (481x475, 41K)

youtube.com/watch?v=oOYrCHi7yjM

I just carry one of these things. Way simpler.

Attached: $_3.jpg (500x290, 15K)

CH-CHONK

that's still basically how it works on cell phones with FM radios and lots of small portable radios, too.

haven't seen a flagship smartphone in the last few years that still had FM radio, but then again, I haven't been looking for it. It would be a nice insurance policy in case cell systems temporarily go down. In the event of a national emergency citizens could still be informed via public radio. Nowadays everyone only has AM/FM radio in their cars.