I want to build a circuit that takes the audio output of the mobile phone (coming from TRS cable) as an input to control 3 or 4 relays depending on the sound frequency played on the phone.
In other words, if I played 16Khz mp3 file on the mobile phone, the circuit should switch relay #1
If I played 18Khz mp3 file on the mobile phone, the circuit should switch relay #2, and so on.
What is the recommended IC for this circuit?
I know that the output of the audio is AC 250mv Peak to Peak.
Any help?
In other words, if I played 16Khz mp3 file on the mobile phone, the circuit should switch relay #1
If I played 18Khz mp3 file on the mobile phone, the circuit should switch relay #2, and so on.
What is the recommended IC for this circuit?
I know that the output of the audio is AC 250mv Peak to Peak.
Any help?