I am pretty new to working with the Pi. My project requires me to send data in ASCII format through the 3.5mm Audio Jack of the Raspberry Pi, which would, in turn, be taken up by some other device. Also, the language I'm using if Python 2.7

If I can, HOW?

  • 1
    It might help to explain this requirement (using the audio jack) and a little more about your project and what you are trying to accomplish. Nov 21, 2016 at 1:22
  • Checkout this link software.intel.com/en-us/android/articles/…
    – rodripf
    Nov 21, 2016 at 1:52
  • Sounds like a school exercise to me.
    – joan
    Nov 21, 2016 at 9:11
  • @SteveRobillard I am using the Pi-3 to record temperature consistently. In the project, there is a requirement wherein I have to send the temperature data in ASCII format to a Telemetry device that will be connected to the Raspberry-Pi using the Audio Jack. Nov 21, 2016 at 12:02
  • @SteveRobillard Any leads? Dec 4, 2016 at 13:35

2 Answers 2


There are several solutions:

  • 1
    Morse code ! Then use another Pi to decode. If you wanna spice things up try the Enigma Cipher!
    – Piotr Kula
    Jan 10, 2017 at 13:54

The simple answer is no.

Strictly speaking it is not impossible. It would be possible to emulate a modem protocol, but this would require a demod at the other end.

  • that is the catch, where I'm stuck. The other end can not perform any modifications to the data it receives and hence should be in ASCII format. Even pure ASCII text would do instead of a file. Dec 4, 2016 at 13:42
  • ASCII is a character encoding standard, not a transmission protocol. Does your receiving device define a protocol that it is expecting to communicate using?
    – Andy Lamb
    Dec 21, 2016 at 17:33
  • Yea.. You may be thinking of sending actual binary using the Audio Jack.. (that is what the iPhone had blocked recently) No.. The audio jack sits behind and Audio synthesizer. You cannot pump binary data to it and expect that to do down the audio cable.. because that jack outputs analog data. Look at the Morse code suggestion! One Pi encodes ASCII into Morse while the other listens and decodes it! You know.. like modernised telegram messages. You cant use that Jack for binary streaming unless you create an analog way to stream binary (aka MoDem) ohh-
    – Piotr Kula
    Jan 10, 2017 at 13:57

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