Docking station and audio over HDMI?


#1

Hello Purism forums :slight_smile:

I’ve pre-ordered my device, yay! I currently use a raspberry pi 3 for much of my desktop computing, and I’m considering using my Librem 5 connected to a monitor to replace it. Convergence :wink:

Would this be an acceptable docking station?

Does the USB C connector support audio over HDMI?

Thanks in advance for any answers :slight_smile:


#2

That would be awesome.
I hope so.


#3

According to people currently having the devkits, USB-C docking support seems not to work properly currently.

You will probably have to wait a few months to be able to know which types of USB-C docks are going to work. But as far as I understand they have plans to support at least some types of USB-C docks, the question is just which.


#4

Thanks for the response.

Do we know if this is a hardware or software issue?

As I understand it the phone won’t have a mini-HDMI port, just USB-C?


#5

(I’m the one who posted about Mini-HDMI and USB-C connectors)

I’m pretty sure it is a software issue because I can see the “data” part of the docking in the logs (with some errors) when I plug the docking.

I plan on looking more into it when I have spare time but until spring I’m working alot.


#6

That’s a relief. Thanks for the info and for your hard work :slight_smile:


#7

Are the HDMI, Audio and Ethernet ports on these Hubs are just USB devices connected by the usb connection to the phone/devkit or is this related to the alternate modes of usb-c?
I ask because if its based on the alternate modes i’m quite sure it is not only defined by software but needs hardware support. Such as putting HDMI or DP signal over the USB-C port not the USB 3.1 data connection.


#8

I found this in the developer FAQ…

Yes, the built-in display of the Librem 5 will be able to run alongside one other external display, via the USB-C connector (either HDMI Alt Mode or Display Port Alt Mode - TBD). However, the dev kits will have a separate HDMI port.

The USB-Cs capable of driving more than one external screen are likely to use something like Thunderbolt - the Librem 5 USB-C connector will not support Thunderbolt.


#9

Yeah that i saw also. I hope for DP Alt Mode, because as i understood wikipedia on this in HDMI Alt Mode the are only enough lanes free for USB 2.0 alongside the HDMI signal. The HDMI Signal can also thranfer 100Mb/s ethernet. So i think an HDMI display hooked up to the L5 could also handle a ethernet connection and some USB 2.0 devices like keyboard and mouse, which is great but DP alternate mode could also handle USB 3.1 devices which would be even better.
What interests me is what happens on these docks if there is a HDMI display connected, are they falling back to USB 2.0 like i, think it must be or is there any other solution to have HDMI and USB 3.1 on these docs at the same time.
Sadly i don’t have any devices that support USB-C, but i try to understand as much as possible to know what devices to by next (Hopefully a Librem 13 v5 with USB-C thunderbolt and a smaller Librem phone. Anything bigger than a nexus 5 is to much for me to compromise :frowning: ).
Having one connection like USB-C for all types of protocols is great, but i think it also brings up alto of confusion what is possible with which device configuration.