Kicad Board Design for Orange Pi 2

create a Kicad board project.

Compute & core board
• Main module: Orange Pi Zero 2 (Allwinner H616, Wi Fi, BT, Ethernet, GPIO headers).
• All existing interfaces on Orange Pi Zero 2 must remain usable:
o Gigabit Ethernet (RJ45) if possible.
o Wi Fi + Bluetooth (onboard radio, keep antenna performance in mind).
o USB 2.0 ports (at least one host exposed, others via headers if needed).
o 26 pin header: I²C, SPI, UART, GPIO.
o 13 pin header: USB, audio/TV-out, IR, extra GPIO (either directly or via mezzanine/adapter).
o Debug UART access.
Cellular connectivity
• LTE modem: equivalent LTE Cat 1/Cat M/NB IoT module.
• eSIM support:
o On board eSIM chip (MFF2 package) connected to the modem.
o Optional footprint for nano SIM as backup is a nice extra.
• LTE antenna:
o At least one main LTE antenna via u.FL / MHF4 to external antenna with 3m cable length
o Ground plane and keep out around RF traces.
GPS/GNSS
• Dedicated GPS module (e.g., u blox / Quectel / similar) with:
o UART connection to Orange Pi (or to LTE module if it supports GNSS pass through).
o External active antenna support:
 RF connector (SMA on enclosure, u.FL on PCB).
 3 m coax cable to rooftop antenna → design for:
 Low loss coax (e.g., RG 174 or better).
 LNA power (3.3–5 V bias) if using active antenna.
 ESD protection and lightning surge protection at antenna input.
Local connectivity
• Wi Fi: Provided by Orange Pi Zero 2 onboard radio.
• Bluetooth: Provided by Orange Pi Zero 2 onboard radio.
• Ensure RF coexistence with LTE and GPS (placement, ground, shielding).
Serial & automation interfaces
• RS 232 port:
o Use a level shifter (e.g., MAX3232 class) from Orange Pi UART to DB9 or terminal block.
• Two RS 485 ports (assuming that’s what you meant by RS234):
o Each with isolated or non isolated transceiver (e.g., MAX3485/ADM485).
o Screw terminals or pluggable connectors.
o Termination resistor and biasing network (jumper selectable).