https://devzone.nordicsemi.com/f/nordic-q-a/38707/multiple-frequency-audio-tone-generationI 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 libraryen-USTelligent Community 13Thu, 03 Oct 2019 22:54:51 GMThttps://devzone.nordicsemi.com/thread/213274?ContentTypeID=1Thu, 03 Oct 2019 22:54:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:23552477-904f-4de3-b9e5-99e19a0f566fNewtoM<p>Hi, you can have a look at this <a href="https://devzone.nordicsemi.com/f/nordic-q-a/52878/pwm-audio-driver" rel="noopener noreferrer" target="_blank">PWM audio</a> thread.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/149517?ContentTypeID=1Wed, 19 Sep 2018 20:36:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:92204a98-c3b9-45ae-ba37-41f91b8aeb9dElias<p>Would&nbsp;square waves be acceptable fixed frequency signals? If so, all you have to do is make a few timer interrupts, each toggling the same pin at twice the frequency of the desired output frequency.</p><div style="clear:both;"></div>