Please forgive me, my native language is not English.

I'm new to radio, but I have several years of programming experience.

I have a raspberry pi 4 model B (hereinafter referred to as pi), 433Mhz RF Wireless Receiver & Transmitter pair (about the receiver and transmitter details, manual).

I want use the pi and receiver to learn control code (or signals?) of my home remote control switch, then use the pi to control the transmitter to send the learned code (or signals?) to control my switch.

But I learned that wireless modulation has FSK, OOK, ASK, PSK and so on. And I found that the operation mode of receiver & transmitter pair is AM (is it equals to ASK?).

So how can I know (check or detect or analyze) which modulation using of my remote control switch?

Does they all need to match same modulation for communicating?

Forgive me for being a newbie at radio, anything that you think is very basic could be very helpful to me.

  • 1
    $\begingroup$ Hello and welcome to ham.stackexchange.com! $\endgroup$
    – rclocher3
    Commented Jan 4, 2021 at 15:56
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    $\begingroup$ Please confirm, for our understanding. It seems you want to use the pi to replace the remote control. Is it correct? $\endgroup$
    – Brian K1LI
    Commented Feb 5, 2021 at 8:54
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    $\begingroup$ @BrianK1LI Yes. $\endgroup$
    – huang
    Commented Feb 5, 2021 at 14:18
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    $\begingroup$ Please edit your question to add links to the user manuals for the TX and the RX modules. $\endgroup$
    – Brian K1LI
    Commented Feb 5, 2021 at 17:29
  • $\begingroup$ It isn't clear if you are asking how to find out more details about how the device under test works (modulation, frequency, etc.) or how to simulate the same traffic because you already know this information. Maybe make that clear in your question. What, exactly, are you asking in relation to all this hardware you have? $\endgroup$
    – clvrmnky
    Commented Jun 20 at 19:06

1 Answer 1


After reading this question a few times, I think I have a good idea what you are asking.

I am not familiar with the transmitter or receiver you mention, but you say they use AM.

Using an AM transmitter, you can not easily (I mean, I guess it might be technically possible if you can vary the frequency of the carrier accurately, extremely quickly) generate FSK, and if you could switch the transmitter on and off quickly, you could generate OOK. I think PSK would not be possible, because you probably have no control of the phase of the carrier. So ... I think the transmitter would not generate the modes you are talking about. As for receiving, I think you can’t receive any of those modes (except perhaps OOK) with an AM receiver.

It looks like you probably need a proper SDR, that can generate all these modes, and others. It will cost more than a simple AM transmitter/receiver, though.

  • $\begingroup$ It's possible, but maybe you don't really understand my question, please read this: github.com/sui77/rc-switch/wiki/Add_New_Remote_Part_1 $\endgroup$
    – huang
    Commented Jan 6, 2021 at 12:16
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    $\begingroup$ @JokeHuang if you feel someone doesn't understand your question, that might indicate that you should edit the question. For example, you here point us to an offsite reference. Why not copy the relevant parts of that into your question? $\endgroup$
    – David Hoelzer
    Commented Nov 3, 2021 at 8:48

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