Is it possible to modify a CB radio to connect to a wireless network, and potentially send any data sent from the radio as a buffer to an outside source like an API? If so, what would be the best way to go about architecting something like this? I essentially just need a way to pull the audio buffer that is created when someone speaks into the mic, and forward that to an API.

I want to connect a microcontroller with WiFi/Sim internet connectivity to the CB and:

  1. Send the audio buffer from the transmitter to the microcontroller
  2. Forward the audio buffer data from the microcontroller to the API
  • 1
    $\begingroup$ Hello! Can you explain in more detail what you are actually trying to solve? Do you already have a CB radio? Why CB? What else have you tried - why not just use a voice recording app on a cell phone, or a zoom call on a laptop, or email a wav file, or use a regular phone to call a voicemail service? Where would the email be going anyway / where is this API? Serious questions to try to understand what your real need is. $\endgroup$
    – tomnexus
    Mar 26 at 20:47
  • $\begingroup$ Hello, thanks! The API would be a publicly hosted server, and essentially I want to connect an external microcrontroller (that already has Wifi / internet connectivity) to the CB and forward any data from the transmitter to the API. So I need to: (1) send the audio buffer from transmitter to the microcontroller, (2) forward the audio buffer from the microcontroller to the public API $\endgroup$
    – Megan
    Mar 26 at 20:57
  • $\begingroup$ @Megan Welcome to hamSE and thanks for your question. CB radio is regulated by Part 95, subpart D, of the FCC rules. We should not offer legal advice but, please, ensure that you don't violate those rules or create means by which others may violate the rules. $\endgroup$
    – Brian K1LI
    Mar 26 at 21:33
  • $\begingroup$ OK. It's a broad question, depends on whether you need 1 or 1000 of them. For one, use a laptop or cellphone with an audio cable connected to the radio's mic. For 1000 units, many wifi-enabled microcontrollers would be able to do what you describe, given 50 hours of skilled development work and some prototyping, say $10k up front cost. If you can distil the requirement down a bit you could ask for help on electronics.stackexchange.com, but basic recommendations like which microcontroller are off topic. $\endgroup$
    – tomnexus
    Mar 26 at 21:34
  • 1
    $\begingroup$ CB radio (US Part 95 of FCC regs) is analog. There is no "audio buffer". $\endgroup$
    – WA9ZZZ
    Mar 27 at 14:43

There's a lot of pieces to this question and it sounds like you've already split some of them off to other sites which is good. It's still a little unclear what you're trying to do with the radio itself:

Send the audio buffer from the transmitter to the microcontroller

In the United States, the Citizens Band Radio Service refers to just one specific set of channels and those are only allowed to be used for voice transmissions (among other restrictions). There are similar restrictions on the Family Radio Service.

That is, neither CB ("trucker" radios) nor FRS ("hiking" walkie-talkies) are allowed for much beyond people talking live with nearby people, and only using unmodified store-bought equipment.

There are only a few casual options where data transmission is allowed:

  • other more specialized Part 95 devices like remote controllers or Multi-Use Radio Service equipment may transmit data but end-users might not be allowed to modify it much
  • the Amateur Radio Service has relatively few technical restrictions, but may only be used for certain purposes — and requires a "ham" license
  • Low power Part 15 stuff (e.g. WiFi, Bluetooth, tiny FM transmitters for your car)

But from some of your other comments, it sounds like you might only be interested in gathering received audio rather than transmitting it yourself? (In radio terms we distinguish a "transmitter" sending signals from a "receiver" listening for them. A "transceiver" can do both, though not necessarily at the same time.)

If you are trying to do something like "scanner monitoring" that's a bit different situation. There may already be lots of options available for that, if you gather the right pieces:

For example the Uniden BCD536HP scanner is a receiver only but can be configured to listen to the CB (and many many other) bands and has Wi-Fi feature already.

Or with the right adapters to reduce the speaker output level of the CB receiver safely as a mic input to an old smartphone, there is likely software available to "stream" that audio to an Internet protocol server.

Similar if you need to use a microcontroller instead: if you already have a solution for the "capturing and/or generating audio" piece and the "connecting to WiFi" piece and the "transmitting audio data to a server" piece, then perhaps you might open a new question about any remaining radio-specific pieces (e.g. dealing with the audio input/output of a transceiver) here on this StackExchange site.


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