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Does anyone know if the 433Mhz receiver boards like the ones I picture below are physically capable of receiving transmissions from These Trust wall switches?

I have both, and am willing to spend time on the software required to recognize a signal but would like to know if the boards are physically able to receive it. They both claim to be 433Mzh based...

These

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  • \$\begingroup\$ What is the RF specification for what the trust things transmit i.e. carrier frequency, modulation type, modulation depth, data format etc... And, who knows what devices are pictured in your question - the one on the right looks like a transmitter so no, it won't be capable of receiving a transmission because it is a transmitter. \$\endgroup\$
    – Andy aka
    Commented Dec 1, 2016 at 11:27
  • \$\begingroup\$ I've used those exact boards, but just for detecting high interference caused by car jammers. They worked fine for my application, and those boards seem to be quite commonly used \$\endgroup\$
    – Makoto
    Commented Dec 1, 2016 at 11:34
  • \$\begingroup\$ I've used the receiver part to receive signals from RF433 remote controls for power sockets without too much difficulty. Took a while to work out the signals but with a scope and then recording the timing of pulses it's not that bad. Just wondered if the signals were going to be receievd even \$\endgroup\$
    – John Burton
    Commented Dec 1, 2016 at 11:44

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if transmitter transmit at 433mhz and at same channel, then those receiver will receive those signals but along with noises, you need to separate those signals from noise, if those switch produce just two commands on/off u can try to decode, if it transmit each time new signals(commands encrypted each time with different key) then u can't....u can build ur own transmitter with less time then trying to decode those signals

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and am willing to spend time on the software required to recognize a signal but would like to know if the boards are physically able to receive it

I'd be much more inclined to spend my time fixing a transmitter and battery into a switch rather than spend time trying to figure out what the proprietary radio switches transmit.

To receive the data you will certainly (and I mean absolutely certainly) need a small micro decoding the transmission received to ensure that it is valid and is error free (as far as this is possible with radio) and you might as well not waste your time trying to understand what the proprietary devices transmit; instead use a micro with the transmitter, read the buttons and...

  • Send a preamble
  • Send an address
  • Send the switch status along with battery voltage
  • Send a checksum

Then, because YOU have defined the transmission protocol YOU will know how to decode the received transmission and not waste time going down blind alleys trying to figure out what the proprietary device transmits.

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  • \$\begingroup\$ All true and I could certainly do that :) and I might! But I have the switch and I have the receiver and I've made it work for other transmitters so just wondered if it was likely possible with this one. Might try anyway for "fun" :P \$\endgroup\$
    – John Burton
    Commented Dec 1, 2016 at 11:45
  • \$\begingroup\$ I think it would be fun trying to decode the switch but, in the bigger picture, where does this really get you? Imagine that you did your own switch and each one had also a temperature sensor. How much more useful would that become when you could also read temperatures in every room (for instance)? \$\endgroup\$
    – Andy aka
    Commented Dec 1, 2016 at 11:56
  • \$\begingroup\$ I disagree with Andy; there have been plenty of people successfully reverse engineering these things, and then the solution can be applied to lots of devices with no further modification. \$\endgroup\$
    – pjc50
    Commented Dec 1, 2016 at 11:57
  • \$\begingroup\$ @pjc50 I'm not saying it can't be done; I'm saying that there appears to be no motive in the question for doing this. \$\endgroup\$
    – Andy aka
    Commented Dec 1, 2016 at 11:57
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    \$\begingroup\$ Fun fact: It's been done before, probably. Friend of mine simply decoded the OOK these cheapo wall-switches use. And wrote a software defined radio transmitter for it. github.com/no-net/wireless_socket_control . That way, he could work from home but still power-cycle devices in the lab :) \$\endgroup\$
    – Marcus Müller
    Commented Dec 1, 2016 at 16:09

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