instead of attach wires everywhere of house with a classic alarm system, decided to built my own by using my home's wifi network.
+ less cost
+ more reliable, no false alarms
+ works via ethernet, so it can be work cable-free by attaching it to wifi router.
+ more stylish than a regular pir sensor
also regular alarm systems just waking up whole apartment when it's turned on, this setup can also notifies the user who walking in other rooms, which room has people etc. which is increases the environment awareness.
time: two business days, approx 16 hours