i am in the middle of designing a very simple door alarm.
please can someone help me decide which way to proceed on the wireless side.(data to be transmitted simple on off) please advise me on the cheapest option. distance max 10m.
Modify a wireless door bell.
also how would i be able to play music through arduino.
You could have the arduino operate a transistor which which controls the power to a gizmo that can play music.