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# Is Arduino can do FM modulation? Answered

Is Arduino can do FM modulation without any additional peripherals.Simply an Higher AC frequency signal with antenna can propagate in air. My question is,can we do FM modulation in Arduino only by coding it,without using any additional peripherals.Generating the carrier frequency in Arduino by coding it and then by performing FM modulation by coding it,getting the external audio signal through Analog input pins and after all the modulation process, connecting a long wire on the digital pin of arduino because the square wave is going to be used as carrier signal.A simple wire can act as a Antenna.Is the above explained process is possible in Arduino only by programming it.

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Do you know,

what frequency modulation %shift is necessary for broadcast any tone ?

Do you know,

a square wave generates multiple frequencies which will create havoc FM and open every garage door in reception ?

OK, Hint you must know about Fourier calculation... As a grad that will soon be charged to do real world design and depends on answers from strangers very sad...

Think about it: what clock frequency can you use, and how fast can you do the necessary maths ?

The clock frequency is 86Mhz to 108Mhz. Modulation is just adding the carrier signal with information signal that is audio signal. Arduino can easily combine these two signals with simple coding.Then what is the necessary to do maths?

LOOK at 20 MHz your Arduino can say do one instruction in 50 nano seconds.

Even if you use a fast video ADC (Analog to Digital Converter), data input, do a multiply/divide on an 8bit number (one part in 256), to decide when to raise or lower an output line might generously only take 50 instructions..

Take 50 instructions at 50 ns each => 2500 ns or 2.5 micro-seconds which means the top frequency the Arduino with a video ADC can produce is no more then 400 kilohertz..

NOW 400 KHz is 200 times slower then 86 MHz and it cannot be done !

No, what's the fastest speed your ARDUINO will work at ? AFAIK its not more than 20Mhz.

If ite were me, I'd just use a DDS chip and the processor. I can't think of a simpler way these days.

Yes, technically it can execute frequency modulation schemes. However, it will not do so at the higher radio frequencies commonly used in FM-band broadcasting., since it doesn't operate at sufficient frequencies to meet those expectations.

If you're thinking of the 87.5-to-108 MHz band, I don't think Arduino(r) is that fast.

I think the usual way to do F modulation, is to just find, or build, a VCO (voltage controlled oscillator)

https://en.wikipedia.org/wiki/Voltage-controlled_o...

that oscillates at frequency in the band you want to use.