Attempt 2: Microphone to ESP32 ADC and DAC
This approach seemed promising in theory. I connected the microphone to the ESP32’s ADC (analog-to-digital converter) to process the input signal and then used its DAC (digital-to-analog converter) to output the processed signal to the speaker. ESP32, with its powerful capabilities, felt like the perfect choice for such a task.
I spent hours adjusting the wiring, ensuring the connections were solid, and tinkering with the code. Despite my efforts, the ESP32 continuously threw unknown errors that I couldn’t resolve. Whether it was a software bug, a configuration issue, or just my own inexperience with ESP32’s intricacies, I couldn’t get it to work. Frustration mounted as I realized I needed more debugging time than I had.
Attempt 3: Direct Connection – Microphone to PAM8403
With the ESP32 option shelved, I decided to simplify everything. This time, I used the Arduino’s 5V pin purely as a power source and directly connected the microphone to the PAM8403 amplifier. No microcontrollers, no ADCs, just a straightforward analog chain: microphone → PAM8403 → speaker.
The result? Only static and electrical noise came out of the speaker. No matter how I adjusted the connections, spoke into the microphone, or modified the PAM8403 settings, the output didn’t change. The simplicity of this setup should have worked, but I suspect the microphone’s signal was either too weak for the PAM8403 to amplify or the input impedance mismatch rendered the setup ineffective.
Both approaches were disappointing, but they added valuable lessons to my journey. I’m not giving up yet. Introducing a proper preamplifier stage to the microphone before it reaches the PAM8403 is pretty necessary after all these experiments. Each misstep is a step closer to a working solution—or so I keep telling myself.