Arduino alarm system with delay at startup

I put a keyboard for activate and deactivate an alarms system with Arduino board and PIR sensor.
My schematic is:

and sketch is alarm_system_2a.ino !
My alarm work in next steps:
– after power on, alarm is OFF, blue led is on

– after you introduce the code (1234* or better #1234* because # clear buffer for old activity) system go to stand-by state, green led is blinking;

– after 20 seconds, system is in waitting (watching) mode, green led is permanent on;


– if PIR sensor detect movement, system begin to countdown, red led flash;

– if you indroduce code, system will be off (blue led in on)


– after 10 seconds (if you not enter the code) buzzer is on (led onboard is on), red led is permanet on


– after 10 seconds, system go to waitting mode, if is movement again, countdown and after buzzer is on, etc;
You can see 2 movies with states of this alarm system:
Arduino system alarm with delay (2)

Arduino system alarm with delay (3)

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1 Response

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