I started this a few years back, but lost interest. I decided to finish the project and have done with it.
The reason I didn’t finish it was because there was no easy method to replace the original USBA with USBC. In the end I had to design a replacement adapter myself. I wanted something that would be as easy to solder as a standard USB plug.
This is the module with my replacement, soldered with wires to check that it worked, it did.
My original design for the adapter, actually this is a redesigned board to make it easier to solder a physical connection to the main board to prevent any turning or leverage ripping the tracks off the main board.
I also intend to finish the adapter I started with the antenna built in, it should be a lot easier now with the replacement USBC adapter. So, there you have it.
Having any module of this kind would be a godsend considering how sketchy the market for USB modems is. From what I’ve seen online, people just recommend tethering your phone, but that’s not a self-contained solution and it’s not very appealing to me. I’m hopeful we’ll get a module like this available one day.
I have been playing with this idea for a long time too and finally decided to complete. I loved what the OpenCom guys did and decided to shrink their module and make it a bit less akward. I am pretty familiar with Quectel as we use it at work. So here’s where I’m at so far:
Just wanted to post this to see what the interest in this would be like. The modem I am using is North America bands with 150/50 Mbps so about as good as you can get in 4G/LTE at the small form factor that would fit in an expansion card. I will be making it all open source but considering ordering some to sell too so let me know what you guys think!
I think it looks fabulous!
Your board screenshot looks absolutely as small as physically possible. Don’t even see a millimeter wasted. Can I ask how far along do you think you are on the board?
I’d say I should be ready to order within a week or so. I preordered some of the non-stock components from JLC already so it depends on the lead time there too. Will keep you posted!
Well, the good news is that the modem I’m using has an EMEA version in the same package so as soon as the NA version tests ok, I can see about doing the EU one too!
I will definitely be ordering one as soon as they’re available! I’ve been trying to move away from depending on my phone for things and hotspot limitations are a bear. My home Wi-Fi is pretty flaky too, so I really need a reliable cellular solution.
Update time! The PCBs from JLC arrived aaand a DIY maker’s worst nightmare happened: the thing doesn’t turn on. After a day of PCB surgery, trying different things, bypassing the USB-C connector, I did some more digging and I think I have a suspected cause: I was working with Opencom’s design and they had PWRKEY and RESET disconnected so I didn’t even question it. The hardware design spec mentions these briefly but it’s not super clear that they have to be touched. Weeelll, apparently they do. I need to add a one-shot to pull PWRKEY down for 100ms every time it powers on. Fun, eh? I will try to verify by delidding the modem and hooking up a switch (tbd if that’s possible) but I wanted to post an update. It WILL BE FIXED if it’s the last thing I do!
Can’t wait to see the new 4G modules… I think of you guys every time I use my phone’s hotspot, we need this card! Keep up the awesome work! (EU version)
