What is the simplest wiring diagram / components for mixing two outputs?
Here is my schematic. Esp32 outputting tone on a gpio, and sending tx/rx interfacing play commands to a DF mini mp3 player.
I want to mix the tone and one channel of the player output and feed it into the "in" of the amplifier.
I don't need a pot since I can control the volume of the signals before hand.
I searched and this is what I came up with
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What ohm resistors are needed? ( 10k?)
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Do I need caps after the resisters? What size?
Background
I tried the pcmtmb library with the hopes that it could handle concurrent wav files. It didn't compile due to timer related issues with the esp32.
There are other chunks of code out there to play audio with DAC outputs of the ESP32 but I have to handle all the buffering, timers, etc. No simple libraries exist yet for the esp 32.
The only clean example I could find for audio over esp32 was a video from pcbreflux which is where the diagram came from.
The DR player doesn't have nearly the functionality of the pcmtmb library (concurrent files playing).
So my work around is to use the tone generator for user inputs and play audio from the DF min player for the rest.