I had automated my washroom’s light, which turns on when motion is detected using Arduino, for timing algorithm. I had used PIR motion sensor in a non-retriggering mode with time potentiometer set to minimum (i.e. around 4-5 seconds of HIGH signal time and then goes LOW). I had programmed Arduino in such a way that whenever the signal is HIGH, turn the relay ON immediately and whenever the signal is LOW turn relay OFF after one minute. To sum up all, I had made a system which keeps light ON for one minute since last motion is detected, if the motion is detected within that minute then system resets the timer and start counting again one minute from that moment.
But I think using Arduino just for that is a waste. Although I know that PIR motion sensor already can handle timing, i.e. keeps signal HIGH till motion is continued, but it is behaving abnormally in my case because many times it didn’t detect motion even when someone’s in washroom and light goes off.
Please, someone, suggest a solution to this problem. Also, can I use NE555 timer IC in the monostable mode for this?