Project Hijack: using the audio jack

[JordiCP]

This is a project/plattform from some years ago, which from time to time I am finding on Internet when searching for some tech keywords

http://web.eecs.umich.edu/~prabal/projects/hijack/

The idea is to power a small device from the same audio jack and at the same time communicate with it through the audio and mic channels.

It seems to me that it has become a bit "obsolete" (the links I find are quite old), I suppose because many proximity communication needs are solved nowadays with BT,Wifi, USB or even NFC. Also, the energy that can be provided through the audio jack is very low.

Anyone has built/used any peripheral (other than audio) which uses the audio jack?

 

[Descartex]

Long years ago, i built an oscilloscope that comunicates with pc via jack.
I remember i had to power it with a cell because it had not enough power to feed the whole components.
I you want to, i can find the files and share it to you.

 

[JordiCP]

Wow!

I would like to test it with android devices, but the underlying principles (harvesting and communication) should remain the same.

I you want to, i can find the files and share it to you.

Yes please, any info will be welcome I would like to contrast different working implementations


Next week I will order THIS to play a little with it

 

[freedom2000]

interesting but probably only with an "intellectual point of view"
IMHO, the board you mention is quite expensive and will have a very limited interest compared to very cheap ESP8266 Wifi boards

 

[JordiCP]

You are right, difficult to beat an ESP8266 in cost terms.

Perhaps the harvesting part is what I am more interested in. The board is for evaluating only. If I decide to do something the BOM can be much cheaper

 

[freedom2000]

Yep.

I did look at this techno to emulate an IR emitter for "non Samsung" phones.

 

[freedom2000]

You are right, difficult to beat an ESP8266 in cost terms.

Perhaps the harvesting part is what I am more interested in. The board is for evaluating only. If I decide to do something the BOM can be much cheaper

For power harvesting why don't you use the USB plug ?
You can find there good 5V DC sufficient to power MCU boards

an example : https://www.b4x.com/android/forum/threads/control-a-rc-plane-with-a-joystick.40568/#content

 

[JordiCP]

For power harvesting why don't you use the USB plug ?

You are right, and I suppose this is the right answer, but will test it for curiosity (I am quite square-headed, see my profile picture )

 

[freedom2000]

and you are right to test it. Keep us informed