Author Topic: Using usb-c to connect to monitor  (Read 6882 times)

highjohn

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Using usb-c to connect to monitor
« on: February 07, 2018, 03:58:24 pm »
If I have a monitor that takes usb-c input, can I use it - with one of the Gemini usb-c ports - to display the Gemini screen?

Thanks.

Murple2

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Using usb-c to connect to monitor
« Reply #1 on: February 07, 2018, 06:46:39 pm »
Quote from: highjohn
If I have a monitor that takes usb-c input, can I use it - with one of the Gemini usb-c ports - to display the Gemini screen?

Thanks.

It is unlikely to work, unless there are linux drivers available for that particular device and even that doesn't guarantee a smooth ride. I've not had any luck getting usb3 displaylink devices to work on arm hardware in the past (although I haven't tried in about a year so progress may have been made since then) . If you post the specific model of the monitor I can give you a better answer.

Update - it seems displaylink advertise android support so I may be wrong and you might be OK!
« Last Edit: February 07, 2018, 06:57:05 pm by Murple2 »

depscribe

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Using usb-c to connect to monitor
« Reply #2 on: February 07, 2018, 07:44:27 pm »
Quote from: Murple2
Quote from: highjohn
If I have a monitor that takes usb-c input, can I use it - with one of the Gemini usb-c ports - to display the Gemini screen?

Thanks.

It is unlikely to work, unless there are linux drivers available for that particular device and even that doesn't guarantee a smooth ride. I've not had any luck getting usb3 displaylink devices to work on arm hardware in the past (although I haven't tried in about a year so progress may have been made since then) . If you post the specific model of the monitor I can give you a better answer.

Update - it seems displaylink advertise android support so I may be wrong and you might be OK!

Somewhere in the course of last month's CES discussion/display, it was either confirmed or strongly suggested that there's something a little hinky about the Planet implementation of the USB-C for display and whatever is standard, such that Planet's cable and only Planet's cable will work, terminating in HDMI. So I wouder if a cable with USB-C at both ends is likely to work at all. It was suggested that this was an HDMI-only issue, though -- something having to do with a per-unit licensing fee for HDMI. So it's possible that nothing I've said here has anything to do with anything.
dep

Atari Portfolio (yes, it still works and yes, I bought it new)
Libretto 110 CT (with docking station and all kinds of PCMCIA stuff)
And, now, a Gemini and, fortunately, a GPD Pocket

terryowen

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Using usb-c to connect to monitor
« Reply #3 on: February 09, 2018, 01:03:50 pm »
It's not just the HDMI licensing fee.  It's also the MediaTek chip. If you look at the phones using these chips, none of them have HDMI out, as it's not implemented.  That's the reason for the proprietary cable.

Grench

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Using usb-c to connect to monitor
« Reply #4 on: February 09, 2018, 02:17:28 pm »
Quote from: terryowen
It's not just the HDMI licensing fee.  It's also the MediaTek chip. If you look at the phones using these chips, none of them have HDMI out, as it's not implemented.  That's the reason for the proprietary cable.

The HDMI output would be of great use under Debian - large monitor support.  I thought I saw footage where they were sending the output from Linux to a display...  Hopefully it doesn't require big piles of binary blobs to get from Debian to HDMI output...?

depscribe

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Using usb-c to connect to monitor
« Reply #5 on: February 09, 2018, 03:39:45 pm »
Quote from: Grench
Quote from: terryowen
It's not just the HDMI licensing fee.  It's also the MediaTek chip. If you look at the phones using these chips, none of them have HDMI out, as it's not implemented.  That's the reason for the proprietary cable.

The HDMI output would be of great use under Debian - large monitor support.  I thought I saw footage where they were sending the output from Linux to a display...  Hopefully it doesn't require big piles of binary blobs to get from Debian to HDMI output...?

Nope, all it requires is the Planet trick cable, offered currently only in the connection kit or whatever it is called.
dep

Atari Portfolio (yes, it still works and yes, I bought it new)
Libretto 110 CT (with docking station and all kinds of PCMCIA stuff)
And, now, a Gemini and, fortunately, a GPD Pocket

Grench

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Using usb-c to connect to monitor
« Reply #6 on: February 09, 2018, 04:06:34 pm »
Quote from: depscribe
Quote from: Grench
Quote from: terryowen
It's not just the HDMI licensing fee.  It's also the MediaTek chip. If you look at the phones using these chips, none of them have HDMI out, as it's not implemented.  That's the reason for the proprietary cable.

The HDMI output would be of great use under Debian - large monitor support.  I thought I saw footage where they were sending the output from Linux to a display...  Hopefully it doesn't require big piles of binary blobs to get from Debian to HDMI output...?

Nope, all it requires is the Planet trick cable, offered currently only in the connection kit or whatever it is called.

That kind of sounds like they're doing something like a direct signal read from what is going to the on-device display then.  Otherwise under Linux you would possibly need to manage the 2nd monitor through xorg.conf magic.  So, it appears likely that the HDMI dongle is limited to only outputing whatever is/was going to the main device display.  Not horrible - but using the on-device and HDMI monitors to display different content might have been fun.  This method is definitely easier to setup though.

depscribe

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Using usb-c to connect to monitor
« Reply #7 on: February 09, 2018, 04:42:35 pm »
Quote
That kind of sounds like they're doing something like a direct signal read from what is going to the on-device display then.

Yup.


Quote
Otherwise under Linux you would possibly need to manage the 2nd monitor through xorg.conf magic.  So, it appears likely that the HDMI dongle is limited to only outputing whatever is/was going to the main device display.  Not horrible - but using the on-device and HDMI monitors to display different content might have been fun.  This method is definitely easier to setup though.

I suppose there's some conceivable reason to want different content on the teeny Gemini screen from that of a larger connected monitor; in my case, anyway, the purpose of the big monitor would be to free me from the dinky built-in one. My plan is to have a monitor and keyboard and power supply all set up in my office, so I can plug in the Gemini device, do work, unplug it afterwards and be on my way with my prose and pictures all nicely residing on the Gemini.
dep

Atari Portfolio (yes, it still works and yes, I bought it new)
Libretto 110 CT (with docking station and all kinds of PCMCIA stuff)
And, now, a Gemini and, fortunately, a GPD Pocket

sobukus

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Using usb-c to connect to monitor
« Reply #8 on: March 11, 2018, 09:10:47 am »
Quote from: depscribe
My plan is to have a monitor and keyboard and power supply all set up in my office, so I can plug in the Gemini device, do work, unplug it afterwards and be on my way with my prose and pictures all nicely residing on the Gemini.

That plan rather falls down with the realization that you cannot charge the Gemini via the USB-C hub. You can connect your stuff, but can only work until the battery runs out … one thing for the Gemini 2 with a better platform than the Mediatek stuff. The full glory of two USB-C ports where you can charge from either one, connect hubs, have Display Port alternate mode …

depscribe

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Using usb-c to connect to monitor
« Reply #9 on: March 11, 2018, 09:50:15 am »
Quote from: sobukus
Quote from: depscribe
My plan is to have a monitor and keyboard and power supply all set up in my office, so I can plug in the Gemini device, do work, unplug it afterwards and be on my way with my prose and pictures all nicely residing on the Gemini.

That plan rather falls down with the realization that you cannot charge the Gemini via the USB-C hub. You can connect your stuff, but can only work until the battery runs out … one thing for the Gemini 2 with a better platform than the Mediatek stuff. The full glory of two USB-C ports where you can charge from either one, connect hubs, have Display Port alternate mode …
I'm told that while there's no quick charge through the hub, it will charge slowly via a normal USB charger through the hub. I haven't tested this (39xx), but am hoping it is so, because this would allow me to proceed.
dep

Atari Portfolio (yes, it still works and yes, I bought it new)
Libretto 110 CT (with docking station and all kinds of PCMCIA stuff)
And, now, a Gemini and, fortunately, a GPD Pocket

LittleHouse75

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Using usb-c to connect to monitor
« Reply #10 on: March 11, 2018, 07:37:12 pm »
Quote from: depscribe
I'm told that while there's no quick charge through the hub, it will charge slowly via a normal USB charger through the hub. I haven't tested this (39xx), but am hoping it is so, because this would allow me to proceed.

Same here.

thefloyd

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Using usb-c to connect to monitor
« Reply #11 on: May 06, 2018, 08:04:00 am »
Quote from: LittleHouse75
Quote from: depscribe
I'm told that while there's no quick charge through the hub, it will charge slowly via a normal USB charger through the hub. I haven't tested this (39xx), but am hoping it is so, because this would allow me to proceed.

Same here.

Not sure where that bit of (mis)information came from. Planet have said straight out that the Gemini won't charge through the hub. I have confirmed that with both the planet charger as well as 3rd party chargers. I've also tried the Gemini with a 3rd party hub that charges my LG v30 and used to charge my MacBook as well. I have confirmed again, with multiple chargers, that the gemini will not charge via a USB hub.

The reason appears to be lack of USB C PD support. None of my 3rd party USB C PD chargers will charge the gemini *at all*, which leads me to believe the Mediatek chipset doesn't support USB PD. PD is required to charge simultaneously with a hub.