Serial Port Expansion Card

As someone who works in an industry that requires serial connection occasionally to configure switches and various lab hardware. It would be great to have a serial expansion slot.

I don’t even have a framework laptop yet because I am waiting for the 16. But being able to have a serial port would be a nice little feature to have for my daily work. I did some research and couldn’t find any so if someone knows of one I can save for future use that would be great!


Welcome to the forum.

Do you mean with a DB9 Connector? Because I don’t believe that would fit on an expansion card.

If you don’t need the DB9 connector, then

I did mean the DB9 connector. Hmmm maybe whenever I get a laptop I will have to look closer at it and see if it would fit or not. Thanks for the help.

One can easily be made from the myriad of serial adapters out there.


I haven’t quite finished this, the socket needs soldering to the board and LEDs added.

Something like this.


@Moe_Wigs what usb c board did you use for that?

It’s a DSD TECH SH-U09B3.

Thank you! Do you have a cad model for the enclosure as well?


You ever get anywhere with this? I’d love to buy 1 or 2 of those off of you.

I found a prototype of one of my DB9 Serial Expansion Cards so I’m going to do a couple short production runs of these, going for 32USD. Stripe Checkout

Don’t tell me that components are off-center or the PCB is routed badly, I just put this together to get a BOM cost and a general enclosure cost.

Updates sent out, so here is a render of the PCB

Here is a photo of the assembled PCB, currently designing an enclosure for these right now!

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All orders have been shipped unless you have made arrangements for combined shipping, or you requested a variation. Tracking numbers will show no change in tracking till Tuesday due to Easter Holidays. I have made a new thread to stop hogging this one which you can look at here: DB9 Serial Expansion Card.

Mods, if you want to delete my past 4 posts, that is fine!