Cheap chinese home alarm systems 433Mhz

On online shops like aliexpress several manufacturers sell cheap home alarm security systems with lots of wireless sensors all working on the 433Mhz frequency.

Has anyone looked into the protocol used and if a binding would be possible via a jeelink (433Mhz version) or CUL stick (433Mhz version)?


It could be worth the effort. A wireless door/window sensor sells at $5.29.


These sensors are received by the RFXCOM RFXtrx433E

My current home automation and alarm is based with these kind of sensors, indeed they are available with RFXCom, if you are looking for a more DIY solutions the protocol can be handled by RCSwitch library either available on PI or on arduino.

If you have questions about this don’t hesitate.

RFXCOM RFXtrx433E may be a good choice but the price tag is too heavy and unproportional. A complete home alarm system for $80 and one addional receiver for 110€ don’t match.
I guess the value of the RFXCOM is not the hardware but the reverse engineering knowhow build into the software (firmware) that comes with it.
I’m familiar and using PI and arduino and will look into the RCSwitch library.

Many thanks 1technophile for the tip.

Please note that mine are bought from banggood (No participations on this site) and working with rcswitch they looks very similar to the ones on aliexpress but I cannot guarantee the compatibility at 100%. More details on the refs there

Regarding rfxcom you’re right firmware is quite interesting due to the number of protocol supported.

You can also use cheap RTL2832 receiver (<$10) and very powerful RF signal analyzer.
Or supporting less protocols but having builtin MQTT client

Hi I have the rfxcom 433 and need some cheap sensors for my shutters and garage doors. Some of the cheap sensors I’ve found only send an Open signal once each time the door is opened and nothing when the door is closed. This means you can’t track when they are closed. What do your sensors do?


Couldn’t you just use two sensors (one for open, and one for closed) to work around this? It’d make it slightly less cheap, of course…

Same thing, they are not giving a state they are reporting an action that i would call “door is opening”. In details these sensors are composed of two parts, when one of the two left the other an rf 433mhz code is sent.
This code is translated by an arduino gateway to mqtt (arduino swich on a siren also). Openhab receive the mqtt signal and with some rules put the house in intrusion state (send email, speak some TTS, … electrify the burglar :wink:

I use them for doors and windows maybe not suitable for a garage door.

As they are sending an action, with two sensors you will know if the door is opening or closing but not if it is open or close. Could be suitable for a part of the applications but not for all.

So in an alarm application, these sensors not very useful? You’d be able to arm the security with doors and windows left open.

Yes you are able to arm with a window or door opened. If you are expecting your alarm system to give you the state of the door/window when you arm they are not the good way to go.
In one year of use I didn’t get this case (let the door opened) I am more worried about the doors not locked but not found a cheap way to cover this.

For a good intrusion detection they should be used with pir sensors , they are some on the first links. They are sensitive and working well (autonomy of around 7 8 months) , the only drawbacks is that you can’t tune the sensibility.

Thanks for the feedback they sound like the ones I’ve looked at before. 2 sensors would probably work but i am sure there is an alternative solution somewhere!