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Several questions about radio wave transmission

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Several questions about radio wave transmission

Postby Leonardo19 » Wed Jun 14, 2017 6:13 am

I have two ATMEGA328P. I would like to be able to send a radio wave (no data/sound/modulation, nothing, just the carrier wave) from one micro-controller and get the other micro-controller to pick it up using ADC.

So far I've been able to pick up random EMP emission with my receiver ATMEGA328P (by connecting a long wire into the ADC input). I can clearly see a unique ~6sec pattern being generated by one of the devices at my home, then it goes silent for ~5seconds and then the pattern repeats again. Seems like it's coming from the fridge or maybe neighbors, because pattern disappears as I move further away from the kitchen. So my 'antenna' is picking 'something' up.

Now I want to be able to simply generate some kind of EMP emission, that could be picked up with my receiver, but this is where I'm stuck.

I don't seem to understand how can I 'send' the wave out from the transmitter. If I simply connect the crystal (16mhz) to the ground and VCC and connect another wire (antenna) to the crystals GND pin, but nothing happens as my setup is wrong. I see that other crystals used in radio tutorials have 4 pins, one of them is antenna, so I believe I need to wire 2 pinned crystal differently?

As far as I understood, this is how the transmitter should work:

Crystal is used to generate sine wave, which in return causes the polarity on the wire/antenna to toggle, which in return produces EMP emission in the frequency of 16Mhz (in my case), this signal then get amplified. Is this correct?

My questions are:

-Crystal value/pin count - Can I use a two pinned 16Mhz crystal to generate a 16Mhz SIN wave and will I be able to pick it up with the other ATMEGA's ADC? ( I don't want to read/process the signal, I just want to be able to read it with ADC and detect it's presence )

-Antenna - I have a WIFI antenna, as far as I understood, I won't be able to use it to pick up 16Mhz frequency since it works in Ghz range, correct? How would I find out the requirements to make an antenna that would pick up this frequency (16Mhz)?

-Signal - If I'm sending a 16Mhz sin wave and my micro-controller is running at 8Mhz, it means that I won't be able to see the 'detailed sine wave', but it would appear as solid 'high' in the listener, correct?

PS: Is there a different term for 'radio wave transmission'? because all the tutorials I come across are AM/FM radio related, while I simply want to generate a 'carrier wave' that can be picked up by another controller.

Thank you for your time!
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