But I recieved 433mhz switches with a chip called “CreaJian-X21”. Have anyone seen these before and have you been able to pair them with a reciever? If thats the case, “as what”?
no idea but since it’s 43MHz you could always try a transceiver and see what you receive when you press the button, then you can save the code and reuse?
If you have no such device you can find some cheap ones on eBay. This one is supposed to have a better range than this cheaper one
There are loads of tutorials on how to control these via a raspberry pi, just google it.