Is it possible to build an alarm system with a siren and RFID keys with no Arduino, only using 5 PIR detectors a raspberry pi a Rfid Rc522 module, and build in speakers output? has everyone ever tried? thank you!
why you want to use 5 PIR sensor?
first, add a RC522 to raspberry and get it working https://pimylifeup.com/raspberry-pi-rfid-rc522/
once you are good with it, use https://github.com/myDevicesIoT/Cayenne-MQTT-Python to send data of PIR and RFID to cayenne and also add the code to play audio through the speaker.