PC Engines APU 3
The PC Engines APU3 boards are very similar to the APU2 boards, but they are designed to use two 3G / LTE modems, so the first two Mini PCIe slots have USB connection and are connected to the two SIM slots, and only the Mini pcie slot on the left has PCie interface.
So in layman terms you can only install 3G/LTE/5G modem cards in the first two slots and a wifi card in the third slot.
The board also has two SIM slots with hardware switching (OpenWrt support for the switch unknown).
Most information about APU3 is the same as APU2 so you can probably look at the article about APU2 boards
There have been reports that “old” SD cards with the 18.06.1 squashfs image are not recognized as bootable, though the ext4 image on the same card boots.
2018-09 -- https://forum.openwrt.org/t/sd-install-on-apu-2c2/21584
Supported Versions
Status
- Full support since LEDE-17.01.4
Hardware Highlights
Installation
See PC Engines APU 2 for installation instructions.
Schematics and datasheets
Bios Upgrade
The onboard BIOS can be upgraded to a more recent version, see the generic article for PC Engines APUs here