Hi Jens,
I'm sorry to disturb you. I want to ask you something about FSKModem.
I run the demo(Terminal.xcodeproj), I can send data(I can hear the sound).
But, the data can not be received. I have no idea if I do something wrong.
Could you help me to check what is going on?
Thank you so much.
Like this:

I try all the Frequency like this:

And here is our frequency in the protocol

Thank you so much.