Industrial KiCad 10 PCB Design — ESP32-S3 24V Opto-Isolated I/O, 4-20mA ADC & RS-485 Modbus

Industrial Hardware & Multi-Layer PCB Layout in KiCad 10: ESP32-S3 controller board featuring 24 VDC opto-isolated digital inputs (PC817), 16-bit 4–20 mA analog current loop receiver (ADS1115 + TVS protection), isolated RS-485 Modbus RTU transceiver with surge protection, relay outputs with flyback diodes, 24V-to-5V/3.3V buck power stage, complete Gerber RS-274X & Excellon drill files, and turnkey PCBA BOM/CPL placement files. Repository: https://github.com/r-menegueli/hardware-pcb-kicad-industrial