Option A: Direct 5V input (barrel jack J1 or screw terminal J2) into eFuse U3 -> P5V_PANEL. Option B: USB-C 5V sink using USB1 with Rd pull-downs R1/R2 on CC1/CC2, VBUS into eFuse U3. Add ESD on D+/D- using D1. Option C: USB-PD 9-12V + buck to 5V (not yet implemented, placeholder). Option D: Wide input 12-24V + buck to 5V (not yet implemented, placeholder). Notes: Use overcurrent protection to cut VBUS on overcurrent events. USB data-line ESD should be bidirectional TVS with capacitance below 1 pF per line (part selection TBD if required).

flowchart TD PWR_IN["5V Input Options"] --> PROTECT["Input Protection and OCP"] PROTECT --> P5V["5V Panel Rail"] PROTECT --> REG33["3.3V Regulator"] REG33 --> MCU["ESP32 Module"] MCU --> HUB75["HUB75 Output Connector"] HUB75 --> PANEL["RGB Matrix Panel"] HUB75 --> HUB75_OUT["HUB75 Chain Output"] MCU --> IO["Debug UART and GPIO"] P5V --> HUB75 P5V --> PANEL P5V --> HUB75_OUT REG33 --> HUB75 PROTECT --> USB_C["USB-C 5V Sink Option"] PROTECT --> DC_JACK["Direct 5V Input Option"] PROTECT --> WIDE_IN["Wide Input Buck Option"]

Option 1: ESP32-WROOM-32E-N16 (U1) - classic ESP32, adequate GPIO. Option 2: ESP32-S3-WROOM-1-N16R8 (U2) - ESP32-S3 with native USB and PSRAM.

HUB75 signals are level shifted from 3.3V to 5V using two 74AHCT245 buffers (U5, U6). HUB75 connectors H1 (to panel) and H2 (chain out) share the same signals.