Niche expansion cards

What about a hardware random number generator that uses atmospheric microscopic phenomena like light, sound, temperature for entropy… Not sure the security implications of doing this through usbc but could be cool.

8 Likes is an open source hardware RNG that should be usable here. I’d love it if I still kept a physical USB port (such as the data-less USB-C port I want, which would have free data lines…) as well.


One of these for when all our friends have Frameworks and we wanna mess with them.

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+1 for a true RS-232 with a DB9 connector on it (Maybe tricky to get -12 +12V as mentioned on my favorite site). Engineers still use this sometimes, believe it or not! Is there a git hub or something for this, @Josh_Cook ?

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looks like it need to be hard-wired (e.g., wired to chipset or CPU directly) to the system. A USB to serial dongle will work, but for how well, I do not know.

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USB Thumb Drive / Memory Stick / Flash Storage Device.

I booted my Batch 5 Framework today, and the gear logo on the back reminds me a lot of KDE and Kubuntu. I opted to boot a Kubuntu 21.10 USB thumb drive, and I got to thinking, it would be cool to have a stealthy USB-C thumb drive in the form of an expansion card. No NVMe needed.

Edit: This is embarrassing, the storage expansion card thing just flew over my head during ordering,… Nevermind…


that would justify the lack of a second internal drive. however, i still prefer a dual internal drive setup as it allow you to true dual-boot. the external one can be used for things like backup and stuff. and even then …

Look, I understand that not everyone has 9 SSDs lying around, but I would imagine quite a few around here have more than two sticks, in the machine the framework replaces or just loosely hanging around somewhere.

Framework’s external drive use SSD-grade controllers and chip, giving much higher performance than a “thumb drive” can achieve, especially in random reads and writes.

I can’t afford to lose a port. I need one for charging, two USB-A (minimum, sometimes I need 3 or 4) and I definitely need ethernet.

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I tested a Kubuntu Live USB key, and had no complaint about the performance. Then again, I am more in the market for a $400 Core i3 model for simple web browsing and email. My Surface Pro 4 is passive cooled, and has an overheating problem…

My complaint is that my chosen USB-C thumb drive, while it fits mostly in the expansion slot, does leave the USB A port sticking out of the slot, which is undesirable. The view from the underside is also not that great.

On the matter of losing a port, I’ve recently read a discussion about the 4-port Intel Macbooks vs the legacy port M1 Macbooks. The discussion was that the USB-C ports utilized the full PCI Express channel, and there were only four full channels on Intel configurations. These channels can be split into whatever ports are desired, but the bandwidth would be shared for all devices on the same channel. Providing four USB-C ports provides the user a clear understanding of what shares what channel, by having them share the same port.

Thus, the multiple USB A ports can typically share a single channel, since most USB devices use less bandwidth than a full USB-C channel. Though, if you do 4k video editing, you may desire multiple 4k monitors, and a couple of SSDs.

The design of the Framework is not about utilizing the full bandwidth of a USB-C port, so much as minimizing the appearance of dongles and USB devices.

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Exactly. but bandwidth is not an issue if you plug in a keyboard, mouse, writing pad, the thumb drive from your colleague, and maybe a USB development board. And maybe a USB oscilloscope.

I might get myself a cheap USB hub.

Exactly. And this is why they are “pro” because you have to buy expensive dongles to connect stuff.

Fundamentally, Framework is also a 4 Thunderbolt laptop. The twist is that they have four modules (a.k.a. built-in-dongles) so you can have whatever port you want.
So, for someone that does not care about aesthetics (and in fact the USB-C “adapter” card does not do thunderbolt very well?) , they might order a machine with no expansion cards and just plug their Thunderbolt dongles in.

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I actually communicated to a electric vehicle motor controller’s RS-232 DB-9 port via an arduino mega programmed to pass through serial data from its usb serial to its serial 1 port. The serial 1 port was connected to TTL to RS-232 logic level converter. I was using the original software that came with the old school motor controller to program it. So a usb to serial converter works in one instance. Maybe different for other hardware.


I never would have thought a new EV would have a serial interface, would be a new fangled USB-C port or a unknown port.

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There are lots of very expensive industrial instruments that are stuck with serial interfaces. Perhaps EVs follow the same thinking - manufacturers of very high end equipment can be very conservative. They go with what they think is old reliable/proven technology for interfaces, none of this fancy USB stuff even though it’s been around for decades.

With no native serial interfaces in laptops anymore it can make things difficult. I’ve long since abandoned Prolific USB-to-serial chips, they’re awful. Fortunately FTDI are much better, but there are still some pieces of equipment that are cranky with converters.


a small Hand warmer.


Or just a game controller like the Joy-Con from the Nintendo switch.

done here :slight_smile:


Nintendo DS game cartridge reader


the … well, the BIOS could be set so it will … no.
It will need to actively detect the type of cards currently inserted, and listen to (because it’s the host) the power card when the button on the power card is depressed. It will then send some bytes over to tell it to turn on, say, 4 LEDs.
And because of we are actually using USB instead of hard-wiring one, we need to do USB handshake and initialization.

That sound like so much work compared to something that used to live on the battery itself. So you only need maybe 50 extra transistors on the battery controller. Yes, not having it on the battery IC still adds this communication, but this can be done hardware (e.g. below even the BIOS layer and in the power management layer), which might be only a few hundred transistors or maybe 50 lines of code)

Ah. good memories.


Not quite sure I understand your reply. I am simply saying I know I got a USB to serial connection to work in one instance. I used the USB to serial converter on the arduino mega board, connected to the ATmega1280’s UART0 pins (TXD0 and RXD0), which was in turn connected to this TTL to RS-232 logic level converter from sparkfun via the ATmega1280’s UART1 pins (TXD1 and RXD1) which was connected to the device with the RS-232 port. However, my project did other things so it needed the Arduino for that, just a converter would not need an extra micro controller. Hence this is not the optimal solution but I know it worked so integrating all these components onto one board should also work.

Also, I don’t believe this would depend on the BIOS. It depends on the arduino USB to serial drivers that arduino maintains. So, if Arduino mega works on framework, this idea should also work on framework. Since this is just an adapter, presumably removing the ATmega1280 and just connecting the Sparkfun TTL level converter to USB to serial chip from the mega would work too.

I also found this which uses " FTDI FT232 paired with a Zywyn ZT213 RS232 Transceiver" so putting these on one board might work too and would be a better design. This would depend on FTDI drivers, presumably.

Yes, this was an Alltrax controller (communicating at 9600 Baud 8N1) if I remember correctly.

Curious @Fraoch , do you use FTDI because the drivers are good? I guess the Arduino USB to serial drivers are not very professional :sweat_smile:

Yes, much better than Prolific drivers. There has been so much counterfeiting of the Prolific chips that the drivers end up blacklisting legitimate chips and rendering them non-functional. Much easier to go with FTDI who don’t have this issue and keep their drivers up to date too.