i thought of doing a remote using the principle of sound waves by adopting FM Modulation. But, the problem is designing the receiver set. i am not prepared to set it mechanically. the receiver is to be plkaced inside the main box or regulator. as the push button switch is pressed, a frequency of sound generated gets modulated and detected by the receiver, but how do i adjust the speed accordingly???
u can use any mod technic for digital data, ask ook fsk with data rate about 9600 baud, just select the trx and replace its data with yours. be carefull about the noise from trx