Ethernet Expansion Card

It may be worth testing what power the card draws. I guess it should be possible to try this as soon as the chipset is chosen, since the casing probably won’t affect the operation. It’s particularly worthwhile to test what power it draws when it is not in operation and when the system is suspended. As it turns out, the HDMI and USB-A do use a noticeable amount of power, even when the system is suspended. That means that for many on-the-road scenarios, using a portable USB-C hub is actually a more practical scenario than having non USB-C expansion cards installed (particularly for wired ethernet, where one will be fiddling with wires anyway; less so for a quick plug of a USB-A stick to transfer a file): unplugging a hub is much easier than prying one of the cards out and leaves the laptop in a better shape for transportation.

RTL8153

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Just had a look, at gigabit and heavy usage it should draw around 400 milliamps and can go into a deep standby but can’t get the current figure.

OK, that looks like a very common chip for USB-C ethernet adaptors. Mine sit in a powered dock or a multi-port hub, so I can’t get reliable data on the power use when suspended.
The experiment would be simple:

  • configure s2idle/deep suspend
  • have RTL8153 dongle inserted (or not)
  • unplug power
  • read charge of battery (in Wh would be good)
  • suspend
  • after a good amount of time (an hour or a couple), wake machine
  • read charge of battery

Difference of charge divided by suspension time (in hours) should get you the power-consumption while suspended. The difference between the consumption with/without dongle should be the power the dongle draws while suspended.

It would be useful information to have for pretty much any expansion card. Devices that draw quite a bit of power while suspended may be better in dongle/hub/dock format than as an expansion card for people travelling (because then the device naturally unplugs when not in use).

What figures would we be aiming for? It does promote deep suspend internally that will put the RTL8153 in a suspend when no network cable is connected.

I’m not sure there’s anything to aim for and/or if there’s something you can do in the card (other than a switch to break the connections to the plug). The measurable power drain from USB-A and HDMI expansion cards while suspended may well be because some devices lead the hub to not power down completely. An ethernet port will likely be susceptible to that, due to support for “Wake on LAN” etc.

There’s probably a market for the card even if the power drain is measurable – hopefully Window’s hibernate does kill the card completely – but for people running Linux it’s a good data point: weighing increased suspend time (at the price of a dongle) against the convenience of a port. It’ll just allow people to make an informed choice.

If it turns out possible to change the firmware so that the board can actually power off the USB hubs on the main board upon suspend, this will probably all be moot, but as of yet, Framework hasn’t given any indication they can change the situation.

EDIT: Here is a message from @nrp that acknowledges they are aware of (at least) the HDMI issue and that they’re working on it: Linux battery life tuning - #22 by nrp

It will suspend itself, no contact with windows or linux even if its being supplied power it will go to suspend after 10 seconds without a ethernet cable.

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Being suspended may not be the same thing as being disconnected from the USB hub. I would have totally expected that the USB-A expansion would draw no power whatsoever if nothing was plugged into the USB-A connector, but that is not the case either.
I’m sure the RTL 8153 does a great job minimizing its power use (which might not be completely 0 if it needs to keep an eye out for an RJ45 getting plugged in), but the power drain might actually happen on the other side of the USB-C connector.

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That makes sense now.

I would love to buy one and help but since I am under 18, I do not sure how much help I would really be also I am California based.

Well I’m actually under 18 as well. I’ll ask for help when needed.

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ok let me know if you need any help with mass 3d print or anything else

@Josh_Cook , are there any updates on the development or production process you can share?

I’ve started work on first few prototypes, completed the first side of the board today and going to do the other side, tomorrow

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Update: I have a prototype working but I need to make a new board as having components either side is way too challenging to place and reflow. Estimated to be ready for first sale start of May. Will post updates later on.

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Literally the only reason I haven’t pulled the trigger yet…

I have placed the order for assembled PCB’s.

@Josh_Cook

That’s great, and what does the final design look like?



This is the enclosure, I do not have the images of the PCB on me, if you want to see them look at the GitHub.

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The prototypes are coming in tomorrow, expect an update.

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