2.4 GHz Morse Code? Why not! - nRF24 in RadioLib

A project log for RadioShield

Universal Arduino Wireless Shield

Jan GromešJan Gromeš 05/31/2019 at 08:431 Comment

For quite a while now, there's been a bit of a backlog in the TODO list in RadioLib readme. Today, I can finally say that I have crossed one of the items off - nRF24 support is now in RadioLib!

I noticed something interesting about RadioLib - sometimes, adding support for new modules has some unforeseen consequences. Thanks to the modular interface-based design, old protocols can work seamlessly with new radios, even if that wasn't the original intention.

This was one of these "unforeseen consequences" - did you know it is possible to transmit Morse code using nRF24? Neither did I, and here's the SDR recording of exactly that:

I believe I have now topped my personal record in "most useless radio application" (previously set by "using SX1278 LoRa module as an FM radio to transmit .wav file"). Who needs data rates of up to 2 Mbps, when you can have good ol' fashioned 120 words per minute! You don't even need nRF24 to receive it, a skilled operator from the early 20th century can do the job for you - assuming you provide him with the equipment to receive the 2.4 GHz Morse code, of course.

Speaking of equipment, mine is rather basic. I'm still using RTL-SDR dongle, which has served me well for the past few years. It does have a small issue, in that it can only receive up to 1 GHz. How did I receive the 2.4 GHz signal you ask? I got an antenna with a down converter! That takes in the 2.4 GHz signal, shifts it down by 2278 MHz and we're in a convenient 100 - 200 MHz range, perfect even for the cheapest SDR. Isn't it an overcomplicated solution to a trivial problem? Of course it is, you could have probably noticed the pattern by now.

And that's about it for this update! More stuff is in development (maybe), so stay tuned! Preferrably to 2.4 GHz for the best Morse code out there!



[this comment has been deleted]

Jan Gromeš wrote 06/02/2019 at 05:19 point

I'm not sure about that, as far as I can tell, there's no way to access the "raw" signal on nRF24. The only thing it can do is measure the received power level, and even then it returns only a single bit of information (above/below -64 dBm). I guess that's all you need to receive the Morse code, but I really don't know how it would work in practice.

I will probably try it out though :)

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