galfert
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Raspberry Pi 4 B - HDMI over USB-C

Tue Jun 25, 2019 3:59 pm

Is is possible to get HDMI output using the USB-C port on the Raspberry Pi 4 B?

I suppose you'd need to provide power via PoE to free up the USB-C port or use some sort of OTG power splitter cable if it exists. Or even better if you could somehow use the NexDock 2 an then only use a single USB-C cable between them, that would be awesome.

jamesh
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Re: Raspberry Pi 4 B - HDMI over USB-C

Tue Jun 25, 2019 4:22 pm

No, this is not possible. There is no route from the graphics system to the USB system for video.
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W. H. Heydt
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Re: Raspberry Pi 4 B - HDMI over USB-C

Tue Jun 25, 2019 8:31 pm

jamesh wrote:
Tue Jun 25, 2019 4:22 pm
No, this is not possible. There is no route from the graphics system to the USB system for video.
Hmm... USB-C port would appear to right out, since it doubles as the power connector, however... I have a Pi2B that drives a 10" adequately through some adapters off a USB 2 port (the native connection on the display is DisplayPort...an early Packed Pixel unit). One would, therefore expect it to be possible to that using a USB 3 port and go to something with pretty good resolution.

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thagrol
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Re: Raspberry Pi 4 B - HDMI over USB-C

Tue Jun 25, 2019 9:08 pm

W. H. Heydt wrote:
Tue Jun 25, 2019 8:31 pm
jamesh wrote:
Tue Jun 25, 2019 4:22 pm
No, this is not possible. There is no route from the graphics system to the USB system for video.
Hmm... USB-C port would appear to right out, since it doubles as the power connector, however... I have a Pi2B that drives a 10" adequately through some adapters off a USB 2 port (the native connection on the display is DisplayPort...an early Packed Pixel unit). One would, therefore expect it to be possible to that using a USB 3 port and go to something with pretty good resolution.
Won't that be using DisplayLink or a similar proprietry protocol? As I recall there is no direct support for GPU output over USB2.
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W. H. Heydt
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Re: Raspberry Pi 4 B - HDMI over USB-C

Tue Jun 25, 2019 9:12 pm

thagrol wrote:
Tue Jun 25, 2019 9:08 pm
W. H. Heydt wrote:
Tue Jun 25, 2019 8:31 pm
jamesh wrote:
Tue Jun 25, 2019 4:22 pm
No, this is not possible. There is no route from the graphics system to the USB system for video.
Hmm... USB-C port would appear to right out, since it doubles as the power connector, however... I have a Pi2B that drives a 10" adequately through some adapters off a USB 2 port (the native connection on the display is DisplayPort...an early Packed Pixel unit). One would, therefore expect it to be possible to that using a USB 3 port and go to something with pretty good resolution.
Won't that be using DisplayLink or a similar proprietry protocol? As I recall there is no direct support for GPU output over USB2.
All I can say it that I set it up and it works. The second gen Packed Pixel displays are supposed to have optional HDMI and the second gen DisplayPort is supposed to work with HDMI, as well. Plus, their second kickstarter campaign included a 13 in. 4K panel.

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