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Topic: NRF24L01+ antenna connected to AC audio line (Read 972 times) previous topic - next topic

MattiasOfTheMetal

Hi,

First, I have a few of these:
http://www.exp-tech.de/images/product_images/original_images/b9e551faebe0bf1227bc08d1b19f285e.image.550x550.jpg

http://www.emartee.com/Images/websites/emartee.com/RF24013.jpg

My question, is I plan to put one of these in my guitar, and one in my pedalboard. So the voltage will be +/- 1VAC.
Will there be an issue with having the antenna directly attached to either of the AC wires?
Meaning, will an AC voltage that low mess up the NRF24L01+?

I have considered using diodes to prevent flow to the antenna, but wouldn't that make it so neither chip could listen, only speak?

I think the audio signal would be fine, considering the nordic chip communicates at 2.4 ghz and would be far out of the range of human hearing. I will also put a filter for above 1ghz to save my pedalboard and amp.

Thanks!
-Matt
Food for thought.
Nom.

tack

You've totally lost me. Why would you connect the antenna of the module to anything, let alone an AC signal?

I don't understand what you are trying to do here.

pYro_65

If you are trying to feed the wireless signal into the guitar signal, I'd imagine the amp or whatever you plug it into would have a band pass/low pass filter which will kill the 2.4 GHz signal. But you said you are adding that in, I'm pretty lost too. Is the guitar cable, or strings supposed to become an antenna?

Docedison

Maybe OP thinks a nRF24XX will handle audio..

Bob

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MattiasOfTheMetal

#4
Feb 01, 2013, 05:14 am Last Edit: Feb 01, 2013, 05:49 am by MattiasOfTheMetal Reason: 1
EDIT:

I understand the NRF24 does not transmit an analog signal. A DAC/ADC combo would be necessary for that.

The attached picture shows the diagram.

In the future I plan to make a 2-way wireless guitar adapter. 2-way is necessary for guitar's and pedalboard's arduinos to communicate, while still passing the analog signal.
This would need to be backwards compatible with a regular guitar cable, and work on any guitar.

My idea for the wireless guitar thingy: (any)guitar->ADC->NRF24->air->NRF24->DAC->amp/pedals/whatever.
So with the NRF equipped guitars, it would be: arduino-->nrf24->(in parallel with guitar signal)->guitar cable->pedalboard->(splits to nrf24->arduino and guitar signal->pedals).
In this case, with the 'wireless guitar thingy', I could directly swap out the guitar cable with it.

I cannot have the nrf24's go through the air, it must be through the guitar cable. (will have no interference if I turn and am between the two nrf24s, physical objects in between the two will not affect performance, better asthetics, not having a 4 inch antenna sticking out of my guitar and having 2 of them when I go full wireless, etc.)
Overall, its better for it to be hidden and operate on a specific line, rather than the airwaves.

Does this make sense?
If the signal goes through the guitar cable, there will not be anything in the way of the transmitted signal, and there won't be outside interference due to the cable's shielding.

Sorry for the confusion.

So, my main question: will a very very low voltage AC signal hurt the nrf24s? I would assume not, since it is well below its operating voltage (even if its AC).

-Matt
Food for thought.
Nom.

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