I have interfaced a simple alarm with a server/client wifi interface, everything is working correctly.
The only thing that is missing is a sorta UPS Usb power supply to arduino, as if a burglar were to cut down electricity, although the alarm/siren have a backup battery, arduino would not be able to sound the siren on/off- this would defeat the purpose.
For this part of my project I had in my mind to connect (in parallel) a mini 300mA battery and my arduino to the usb outlet: whenever the electricity were to be cut off, my arduino module would have some more time before powering down.
Am I overthing this? Maybe connecting arduino directly to a common powerbank would grant me overcharge/discharge protection