Conservative first-revision TIMI prototype built around ESP32-S3-WROOM-1-N16R8 with USB-C 5V input, native USB, 3.3V regulation, onboard MAX98357A audio out, external INMP441 header, status LEDs, buttons, UART debug header, required test points, and 4-layer antenna-conscious PCB constraints.

Audio-first ESP32-S3 wearable PCB. 44 × 26 × 1.0 mm. ESP32-S3-MINI-1 + INMP441 + TP4056 + DW01A/FS8205A + ME6211C33. 800mAh 802545 LiPo. Native USB on GPIO19/20. BLE audio wearable.