So, the product page for DevTerm says that the ext board is mini PCI-e. Does that mean it is going to provide the necessary power for standard mPCI-e modules?
I want to connect cellular modem or LoRa WAN modules like: WisLink LPWAN Concentrator | RAK5146 – RAKwireless Store
Hopefully, there is enough space in the case too and holders for the screws at the end of mPCI-e boards
will it fit? it sure looks like it will… i have a concern, however. the core modules follow the format as DDR2-SODIMM, but uses custom pinouts because this is all custom development gear designed using existing parts readily available.
Will the EXT port be compatible with miniPCIe devices or does it use custom pinouts? Unfortunately, I do not have enough training to answer this… however i am confident that there may be members lurking these forums who could answer your question, even in regards to the issue i raise.
hmm. given that it is custom pinout, i wonder if it is compatible with mPCI-e.
if that is the case, i wonder if i can stick in an empty pcb and wire it to make a custom lorawan “HAT”.
But, too soon to tell. I am waiting.
It is not PCI compatible, it use the same form factor, but it is NOT PCIe nor PCI
If you want to check just go on CPi’s github and look at the schematics:
Here is an example of one that should work.
I am very interested in designing a core module board that is PCIe gen 2 compliant both mechanically and electrically. RPi CM4 I think gives us the first opportunity to since it breaks out a PCIe x1 host interface. For that reason I am leaning toward overhauling the core module to support mounting a CM4 directly instead of SO DIMM conversion. Anybody have multilayer PCB and differential signaling experience? Or know of a good PCB house 
The expansion board could then have an FPGA and/or PCIe switch and any number of peripherals. sky’s the limit!
Coming back to this thread a long, long time later…
So we now have the CM4 module - and CM4 supports a PCIe channel… any idea if the ext card could be massaged to help here?
No it is not possible, for that you will most likely need a dedicated mainboard for the CM4