I have some experience in programming using Arduino 2 years ago. Now, I am looking to start on a new project that is to have one arduino to emit various frequencies for a short amount of time and the other arduino to detect the frequency that the first arduino is emitting.
The ideal frequency is in the GHz range but I have come to be aware that it is illegal to emit such frequencies. I did some research and I saw that there is a project using the Adafruit Si5351 10kHz - 225MHz RF Generator. That device should fit the bill as long I could emit various frequencies and have the other arduino pick it up wirelessly.
The distance will be about 1~2 meters apart. It will be used for a demostration in a small room.
It is not neccessary to transmit any data as I would like to prove that my main arduino is emitting those frequencies by the receiving arduino.
The topic for my project is to have a device that is able to emit the range of frequencies that our mobile phone and other communication devices emit. They are within the 30 MHz to 30 GHz range.
That's a clock generator breakout board. My RF knowledge is limited, but I suspect you would need additional electronics to make use of it in your application.
Most of the RF spectrum probably has restrictions on it. You need to check what is legal where you are as it varies from country to country.
I thought it was illegal to listen to other peoples mobile phone conversations. Building your own receiver for those frequencies would allow you to do that and so would be illegal. Commercial receivers have these frequencies locked out.
In the US, that last time I looked there was no law about listening to anything that your receiver receives. What is illegal is to disclose to anyone else what you have heard.
We used to have an old analog TV that received UHF TV signals. When that frequency range was given over to cell phone use, we could listen to one side of the cell use that came from a nearby call tower. Usually nothing to hear and really boring.
That's right, it's a legacy law. Nobody takes that seriously any more, digital cell signals have a high level of encryption. I think the law might focus on manufacturing and selling devices that can receive cell signals, vs. an individual using some device to receive.
But transmissions in the same frequency range can still interfere with them.
I'm certain there was a US law prohibiting listening in on cell phone channels during the IS-136 analog phone era and it's probably still on the books. Obviously it's largely unenforceable unless the listener divulges information from these calls. As a practical matter, with modern encrypted digital cellphone calls it's virtually impossible to intercept and demodulate over the air.
More germane to the original posters project transmitting all over the frequency spectrum is not legal and is likely to eventually get noticed by the authorities and they will not be amused.
Yeah. The authorities put enforcement more where the public and private money is - places like the commercial emergency communications bands (police, fire, etc) and the cell phone bands (multi billion dollar industry). That is where the maximum fines will be levied.
The cell phone lab I worked in, had a walk in Faraday cage for this sort of work.
