Again I am running into problems!. Thats how I learn always!..
Well I am stuck with another problem(?). I have a power supply 6V connected to the motion sensor(Alarm pin is NOT connected to Arduino). Here is the sensor http://robokits.co.in/shop/index.php?main_page=product_info&cPath=11&products_id=234
An LED is connected to the alarm pin and then grounded.
The problem is that the LED blinks always! irresptice of the motion.!
Interestingly , it works perfectly fine when powered from the USB port of the computer!! . Meaning it will blink only When I move around it.
Another interesting fact is that the same circuit connected to the external Powersupply is working fine in night times!!!. (There are two things that I guess, either the voltage increases in night time and hence the power supply is able to give enough voltage to the circuit - but if that is the case, increasing the voltage should work fine. right? it did not happen. OR the kids in the other apartment is sleeping instead of moving around the wall behind!)
Initially I suspected that my power supply is not giving enough voltage.So I checked with the multimeter.It showed me 7.9 V which is enough for this sensor( i believe). The powersupply that I have is 12V variable power supply which can produce 500mA. Could you please suggest me what could be the problem?