Isolated Polyphase IIoT Energy Meter with ESP32-S3-WROOM-2-N32R16V & ADE9000 | UART Programming Pads | 100 nF Per-VDD Decoupling + 10 µF Bulk on 3.3 V Rail | Defined RF Antenna Keepout | USB-C UFP 5 V Input with eFuse | Maintained HV/LV Isolation