Dual USB-C Expansion Card

[Lucas_Lindfors]

Looking good! Excited to see your progress.

[Jacob_Eva_LES]

Nice job bro, I’m rooting for ya

[jared_kidd]

@MJ1

The estimated price is where I expected.
This is a small run, complicated build assembled by a community member. Just look at the pictures. This is not a simple or easy board.

I would actually prefer being able to buy the board by its self for a reasonable price. Then I could put it together and 3d print the rest myself. In any case, if the price can’t be brought down to one people are willing to pay, then he can always just make them for himself, or a smaller run for the ones who are willing to pay a high price.

And who knows, maybe Framework themselves would be interested in producing this.

[GroundCrazyMae]

This is looking lit… Hopefully it is just the two lines mixed up…

[GroundCrazyMae]

@jared_kidd

And who knows, maybe Framework themselves would be interested in producing this.

They are aware of this project at least since they posted this project on their social media …

Maybe they can license it or something …

[dfh]

How is the charging behaviour with this module? Does it support USB-PD?

[Ethan_Spoelstra]

@tbe

But at least it’s looking relatively good by now:

The one thing I’d say is if you could manage to get the spacing the same as the MacBooks that would enable compatibility with a ton of docking stations and port expanders as long as they aren’t expecting thunderbolt 3 speeds on both ports, and honestly I think the number that expects that is really low since the accessories for the MacBook Air and many others were only USB-C and not thunderbolt because the components for thunderbolt had not gotten small enough.

[MJ1]

@dfh

Does it support USB-PD?

USB-PD support would be complicated. I don’t think there’s space for it.

[jschievink]

@Ethan_Spoelstra

that would enable compatibility with a ton of docking stations and port expanders as long as they aren’t expecting thunderbolt 3 speeds on both ports

To my knowledge, there is no practical way to support USB alternate mode with an expansion card like this, so docking stations would be limited to USB 3 only.

[ATi]

Here’s an adapter with 3x USB-C and 1x PD for reference:
https://www.delock.com/produkt/64174/merkmale.html

Maybe the dual USB-C expansion card can be realized using those parts…

Note
DisplayPort Alternate Mode (DP Alt Mode) is not supported, so no video signals are transmitted and no monitors can be connected.

[Geert_Schuring]

@Philam

… always having a USB-C drive with you that you literally cannot lose.

I had not even considered that strangely enough. Its indeed more like a very big USB stick than an extra internal SSD…

[Alan_Pearce]

Well, Framework have 1TB and 2TB expansion modules already listed …

[tbe]

@dfh

How is the charging behaviour with this module? Does it support USB-PD?

It only supports basic USB 3.1 Gen1 (5G), with no fancy addons like PD, alt-mode (displays) or something.
That’s in my opinion the biggest downside of USB-C, you never know what the ports are actually capable of, causing confusion at some point. A good example are the AMD Framework devices (or this hub here ) where even in the same device some ports support this and some that.

@ATi

Here’s an adapter with 3x USB-C and 1x PD for reference:
https://www.delock.com/produkt/64174/merkmale.html

Maybe the dual USB-C expansion card can be realized using those parts…

I’m having a hard time getting the basic hub onto the quite small PCB area (26x30mm) inside an expansion card. If sky is the limit pricewise then probably. The hub-chipset used has basically the same functionality as the one I used, but I don’t think there’s space for the PD-controller, even when adding another daughter-board (would probably look interesting tho) but I think it wont fit in the restricted height and at some point the power converters needed could impact the USB-performance because of interferences but I’m no professional here, this is still a hobby-project (pretty involved for that tho).

Additionally some of these more advanced chips don’t have publicly available datasheets or design resources and you would have to sign an NDA contract as a company to get these things. That’s why I chose the Mircochip hub-IC, there are reference designs, design guides, checklists and datasheets available.

I think we can agree on that this adds one additional port, so I’m not sure how far we should push it in terms of complexity.

Also a quick update: I have fixed the error on the daughter-board’s upstream port in the design files and did order a few (5, that’s the minimum quantity) of them, when they arrive I’ll report back .

[ATi]

The hub-chipset used has basically the same functionality as the one I used, but I don’t think there’s space for the PD-controller, even when adding another daughter-board…

I had the impression, the PD functionality had already been ruled out and the issue was getting both ports to have USB SuperSpeed (5Gbps), hence my reference suggestion.

I’m sorry if I misunderstood and you’re already able to realize that with your current design.
Can’t wait to hear about your further progress.

[dfh]

@ATi

I had the impression, the PD functionality had already been ruled out

Apologies in case I overlooked this and my question has been answered before.

@tbe

It only supports basic USB 3.1 Gen1 (5G), with no fancy addons like PD, alt-mode (displays) or something.

Thanks for the details.
My primary question was trying to understand if my laptop could be charged through the module or not.
From what I understand charging requires USB-PD so the answer would be a no

[GroundCrazyMae]

@tbe

I think we can agree on that this adds one additional port, so I’m not sure how far we should push it in terms of complexity.

This in and of itself is worth it’s weight in gold…

[Katharina]

Heya! First of all: congrats on getting the boards built Very excited to see how this progresses.

I haven’t been following the thread that much, so sorry if this is obvious to everyone else but I thought I’d ask to clarify:

Do you mean that NEITHER of the ports will support charging/ DP, or that only one of them will? I have no idea how USB-C works tbh, so I don’t know if both are out of scope.

I’m currently trying to figure out if a framework would work for me (since I have pretty steep port requirements) and this seems like an important distinction.

Thanks, and good luck!

[Jonathan_Haas]

@Katharina

Do you mean that NEITHER of the ports will support charging/ DP, or that only one of them will?

Likely none. Enabling DP on one of the ports might be theoretically possible with some clever electronics, and would probably downgrade the other port to USB 2.0 when used, but given the size constraints and required knowledge for developing something like this, it’s probably unfeasible.

Charging is pretty much out of the question due to the size constraints. The only way it could maybe work is if the non-charging port would be permanently limited to USB 2.0 and to a very low maximum power output.

If you need such functions, I recommend getting an external hub/docking station as linked above.

[tbe]

@Katharina

Do you mean that NEITHER of the ports will support charging/ DP, or that only one of them will? I have no idea how USB-C works tbh, so I don’t know if both are out of scope.

Exactly, sadly none of them can do anything but plain USB 3.1 Gen 1. More functionality would require even more chips on that small board that are either not publicly available or just don’t exist.
The short version is USB-C ports can be configured to do different things through some of the pins, there’s no real minimum spec, it’s possible to have a port that can do nothing but charging, maybe have only USB 2.0, maybe can’t do anything but displayport-output, from the outside by looking at the port you cannot figure that out (you can’t even see if it’s a host or device port or it can act as both).
Additionally if you could enable charging on one or both ports, you have 20V (the USB-PD charging works at 20V on the Framework Laptop) on the supply rails that has to be stepped down to 5V for the other port (and from there to 1.2V and 3.3V for the chip’s supply) and converting 20V to 5V at around 2A requires quite some board area. So in my opinion unless there’s some highly integrated specialised chip that can handle all that, it’s just not enough space.
In my opinion it’s an okay-ish limitation to have only USB 3 on the hub, especially since the AMD Framework devices do also have ports that only support regular USB (and no alt-mode, charging or thunderbolt). And since this seems to be the first functional prototype in this thread at all .

[Katharina]

@Jonathan_Haas

Charging is pretty much out of the question due to the size constraints. The only way it could maybe work is if the non-charging port would be permanently limited to USB 2.0 and to a very low maximum power output.

@tbe

The short version is USB-C ports can be configured to do different things through some of the pins, there’s no real minimum spec, it’s possible to have a port that can do nothing but charging, maybe have only USB 2.0, maybe can’t do anything but displayport-output, from the outside by looking at the port you cannot figure that out (you can’t even see if it’s a host or device port or it can act as both).

Thanks for the in-depth explanation! That’s a shame, but that does make a lot of sense. And having a card that can have 2 USB ports on it is already a huge step-up. I guess what I’m gonna be doing is switch to a USB-C Yubikey and get one of these cards when it comes out. That should make me happy (I work in the field a lot and have pretty steep port requirements, so it was sad to see that the only USB-C ports were basically passed through 1-to-1 from the laptop.

Anyway, good luck with the rest of the production and testing Do you have a tentative idea when the first batch might be for sale? Or when the project is in a state where someone could assemble their own? I assume the enclosure would be the hardest thing to come by unless you were to 3D print one