How can I use a LM2907 and a microphone to distinguish between two given frequencies; either 5400 Hz or 1900 Hz? Answered
I want to use a LM2907 and a microphone to pick up a frequency (also be able to distinguish between the two frequencies and background noise). I see before me that there will be two outputs. 5V or 0V for "picking up frequency" or "Just background noise" and another output telling whether the microphone picks up the 5400 Hz or the 1900 Hz by 0V or 5V, respectively (the order is not that important when I recon I just can put on an inverter).
What I need to know is the values for my C´s and R´s in the circuit. Can anybody help? I think the Minimum Component Tachometer-circuit will be a good starting point.
The outputs are used for inputs for logic gates.