I am trying to see if there is a way I can generate a multi frequency audio signal without additional hardware. I am talking about something similar to DTMF. The audio wave will contain say 3 fixed frequency tones.
i wonder if I can use PWM library for this purpose. But, it looks like I can only generate 1 frequency per output pin. How about using the DSP capability of the NRF52 chip?
Any idea will be greatly appreciated.
Thanks,
Joseph
