Dual USB-C Expansion Card

[Josh_Cook]

@tbe

Since it’s powered by one USB-C port on the laptop that can provide 3A I don’t think it’s clever to allow the whole 3A on one hub-port when you can plug in two things (and the hub itself also uses some power).

You can only pull 1.5A without a PD controller.

[tbe]

@Josh_Cook

You can only pull 1.5A without a PD controller.

Hm, seems you are right, I did read somewhere it can provide 3A but haven’t thought that might be PD .
I haven’t measured what it is actually willing to give but the port says it’s 1.5A capable.

Edit: It provides around 2A before the OCP trips. So I probably have to go into implementing a PD-IC for that. There are luckily relatively inexpensive chips out there.

[Brunoais]

It would be awesome if it could pull 10V and then split 5V 5A for each split but I have no idea how hard that is because it would need to be in series and it would need to manage to swap 10V into 5V if something is unplugged, which can cause a disconnect of the 2nd thing plugged in.

[MJ1]

@Brunoais

It would be awesome if it could pull 10V and then split 5V 5A for each split but I have no idea how hard that is because it would need to be in series and it would need to manage to swap 10V into 5V if something is unplugged, which can cause a disconnect of the 2nd thing plugged in.

The Framework Laptop will only provide 5v. Laptop ports are just not meant to be a high-power supply.

[Brunoais]

@MJ1

The Framework Laptop will only provide 5v. Laptop ports are just not meant to be a high-power supply.

Framework laptop USB ports support Power delivery.

[MJ1]

@Brunoais

Framework laptop USB ports support Power delivery.

They support USB PD input, not high-power output.

[Andrew_Eastman]

@tbe

(and hope someone buys them )

I’d want 1, no hesitation. Charge what they’re worth, don’t sell yourself short.

[GroundCrazyMae]

I’d say worry about PD later … Maybe a gen 2 addition?

[ATi]

@GroundCrazyMae

I’d say worry about PD later … Maybe a gen 2 addition?

I second that. If you want PD, you’re better off using a powerbank or a USB power supply nowadays.

[Adrian_Joachim]

I’d say screw pd in this case. Having pd would require power muxing and a buck converter for the second port which is going to be tricky to fit and probably relatively power-hungry for very little gain.

[ChefCanoli]

As of right now, how much do you expect it to cost for the parts, assembly, and shipping?

Do you have any plans for a 3d-printed metal case?

[Petr_Sedlacek]

@ChefCanoli

Do you have any plans for a 3d-printed metal case?

Excuse me, where can I get affordable metal 3D prints?

[Nathan_Wolf]

I’m ready to buy… anytime.

For real, I have a use case for this already and would like to compensate you for all your engineering and development.

[CGE]

Similarly, without wanting to make this a thread of people repeating the same things, I’d be interested in purchasing one of these with its current features.

When I find myself short of type C ports, it is usually because I’m plugging in more low-speed, often short-term uses, things like hardware keys, transmitters for presenters, wired keyboards/mice, simple audio interfaces, etc. These don’t need more than standard 5V/1.5A, and don’t need more than 3.1gen1. Having one of these expansions would mean that those devices wouldn’t need to take up the fully-featured ports.

[Benn]

@Petr_Sedlacek

Excuse me, where can I get affordable metal 3D prints?

Maybe here, depending on what affordable means for you?
JLCPCB

[Randy_Braun]

I’d love to buy some of these! Don’t need PD, or anything else, just USB 3.1 gen1, that’s it, that would be fantastic!

[tbe]

I did just order a few very simple USB-PD chips to experiment with. It could be implemented with very few components (like the IC and two resistors for minimum configuration), also it’s quite small and fits into the unpopulated area on the daugther-board, so the FW handles the 3A over to the hub, instead of the default 1.5A (thanks @Josh_Cook for pointing that out ), which could be a bit low for connecting two devices).
The chip will only negotiate the 5V/3A from the laptop to the hub, so still no charging option.
I also did fix an error in the schematics of the main board (the supply for active cables was incorrectly wired).
I’m getting a few bucks tax-money back this or next month, I’ll probably invest that in a few assembled boards once I did iron out things and got the PD-thing running.

[tbe]

The dev-boards for the PD-controller I designed and ordered are here . It works fine convincing the framework to handle over 3A with the PD controller. For the next revision I’ll add the PD chip on the daughter board .

That’s how these simple boards look like:

The chip in the center is the one handling the PD (it’s a HUSB238, in case someone is interested in details).
I assembled three different configurations, the framework only can handle 5V but I wanted to try some other voltages for using them with USB-PD supplies. The other two are 9V/2A (that’s what for example iPad chargers use) and 15V/3A.
It’s quite simple to use the chip, it is programmed by two resistors that set the voltage and current it should request. There can also be programmed some more advanced things like fallback voltages and stuff by an external interface to a microcontroller, haven’t tried that yet tho (the white connector is for an I2C bus).

[Bennett_Derrico]

Might be a stupid question but how are you fitting everything with the PD board into an expansion card shell?

[MJ1]

@Bennett_Derrico

Might be a stupid question but how are you fitting everything with the PD board into an expansion card shell?

He only needs to fit one black chip and two resistors.