Audio Output Architecture: I researched the audio output stage for PocketPlayer and decided on a provisional architecture using the PCM5102A stereo DAC followed by the TPA6133A2 stereo headphone amplifier. The ESP32 sends digital audio to the DAC over I²S, the DAC converts it to analog stereo audio, and the headphone amplifier drives the final 3.5 mm stereo headphone output. I also documented the complete signal path in architecture.md.
Microphone Comparison & Selection: I compared the INMP441 with alternative I²S MEMS microphones, including the ICS-43434 and SPH0645LM4H-B. I evaluated factors such as I²S compatibility, SNR, frequency response, power consumption, size, and availability. I decided to keep the INMP441 as a provisional candidate while continuing to verify availability before the final purchase. I also updated the PocketPlayer component documentation with the comparison and selection reasoning.
INMP441 Microphone Research: Researched the INMP441 digital MEMS microphone and documented its I²S interface, voltage requirements, audio specifications, ESP32 compatibility, and recording architecture. I also noted that the INMP441 is currently listed as NRND, so its availability and possible alternatives will be checked before final purchase.
Session 3 — Hardware Research: I continued PocketPlayer’s hardware research by verifying the SSD1306 128×64 OLED and EC11 rotary encoder. I documented their relevant specifications, interfaces, compatibility with the ESP32, and physical dimensions that still need to be verified from the exact parts before CAD. I also added the rotary encoder’s user-input architecture to the project documentation. Next, I will research the microSD storage system and continue verifying the remaining hardware.
Session 1 + Session 2 — PocketPlayer: I set up the PocketPlayer project, created and connected the GitHub repository and Hackatime tracking, and established the initial project structure. I then began hardware research and verified the ESP32-DevKitC V4 using Espressif’s official documentation, documenting its relevant interfaces, power options, and GPIO considerations. The next step is to research and verify the remaining components before finalizing the hardware desinging
