I work with a modem for transmitting data on a sound line.
It's a FSK modem. Frequency, shift, modem.
Two tones are transferred. 1000 Hz and 1160 Hz.
1000 Hz is a 0 and 1160 is a 1.
I've made two butterworth filters on these frequencies.
I need help creating an interface between the filters
and a digital output on a GPIO pin.
A comparator must be created which detects which filter is
has the largest audio signal and converts it to 0 or 1 on the output.
Can anyone help with that?
The transmitter I have made with two sine oscillators and one mux.
Mux is controlled with a GPIO input.
Regards Helge Fykse