Last night I had the idea to try and built an Express Card module that has one or two USB-C ports (running at USB 2) speeds. I think it's pretty straightforward as the expresscard standard has USB2 pins, I just need to connect them to a USB-C port. Would be interesting to look into slapping a hub in there and putting a RP2040 or ESP32, a serial port or something. A quick skim through [the spec](https://web.archive.org/web/20140625014215/http://www.usb.org/developers/expresscard/EC_specifications/ExpressCard_2_0_FINAL.pdf) confirms I'm right, there's some pins to pull up to trigger USB mode, but that's it. Got PCIE as well, which would be fun to explore as well. Maybe make an open hardware [expresscard to NVMe](https://thinkmods.store/products/expresscard-to-nvme-adapter) (also this review of the [aliexpress version](https://ounapuu.ee/posts/2022/10/04/testing-expresscard-nvme-ssd-adapter/) is making me want to buy one...) https://github.com/xjtuecho/ExpressCard_34M2 was a good read (via google translate) of an NVMe expresscard, which did bring up a MAJOR hurdle: expresscard does not have a 5V line, and thus can't really do USB properly. I've ordered 2 USB3 Cards to use either to harvest the connectors from, or maybe to desolder the large USB connector and replace it with a smaller one. I also ordered an NVMe drive holder because it breaks out the USB pins. Maybe I can add a simple boost convertor and a USBC connector on a daughterboard. Specifically [nvme expresscard](https://www.aliexpress.com/item/1005003444599237.html?spm=a2g0o.order_list.order_list_main.5.39df1802LVhZiQ) and [express card USB 3](https://www.aliexpress.com/item/1005002947933184.html?spm=a2g0o.order_list.order_list_main.10.39df1802LVhZiQ)