I'm trying to control audio level/gain (from line or amplified signal) using an Arduino. I do not want to use SPI, for this project I can only use the PWM outputs, thus I do not want to use a digital pot. I found some related questions here, but they do not fully explain how this approach applies to audio applications.
From the PWM I know I can use a low pass filter, but I want to save time and space using a DAC chip. One option is the TDA1543 (http://www.docethifi.com/TDA1543_.PDF).
So my questions are:
- How do I connect the PWM and audio in/out using the DAC TDA1543?
- Will this approach work as an audio pot controlled by PWM or is there a more straightforward option?
The TDA1543 has 8 pins:
1: bit clock input
2: word select input
3: data input
6: left channel voltage output
7: reference voltage output
8: right channel output
Where do I connect the PWM, and audio in and out? I believe I also need to indicate the resistance somehow or add resistors such as in a 10K pot (amplified) or 100K pot (line).
Any help will be very much appreciated!!