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Author Topic: Puzzled about USB configuration  (Read 6735 times)

depscribe

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Puzzled about USB configuration
« on: March 17, 2018, 09:54:15 am »
I'm a little puzzled about the USB-hub configuration. My hope, based on some presumptions, was that I could plug my Gemini into a charger, monitor, mouse, and keyboard (and at some points an external SD card) to have a temporary desktop machine, docking-station style.

But unless I missed his meaning yesterday in the video, Davide seems to say that only the right-side USB port can be used, for monitor OR mouse OR keyboard. What the USB-3 sockets on the hub are for remains a mystery, though we have a report that standard USB chargers can be used for charging through the hub, albeit not fast charging.

Have I misunderstood all of this? I think I surely must have; otherwise, except for the ability to plug it in either way up, USB-C, as manifested on the Gemini, seems less useful than other USB iterations, and I can't believe that that is true.

So. I know that the monitor can be used only from the right USB socket. What can be used through the hub? Keyboard? Mouse?
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dep

Atari Portfolio (yes, it still works and yes, I bought it new)
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vader

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Puzzled about USB configuration
« Reply #1 on: March 17, 2018, 11:29:26 pm »
The left USB is the charging port. It also supports hubs. I have a third party satechi hub/card reader/ethernet/hdmi. Now hdmi doesnt work but everything else does. I also have a usb c to  usb a adapter which works on the right side. I have used a card reader, ethernet and even a logitech joystick on the right usb.

Basically, the left USB is a fully functional usb port plus charging port, and the right one is for a single  device only - including hdmi out.
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depscribe

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Puzzled about USB configuration
« Reply #2 on: March 17, 2018, 11:53:38 pm »
Quote from: vader
The left USB is the charging port. It also supports hubs. I have a third party satechi hub/card reader/ethernet/hdmi. Now hdmi doesnt work but everything else does. I also have a usb c to  usb a adapter which works on the right side. I have used a card reader, ethernet and even a logitech joystick on the right usb.

Basically, the left USB is a fully functional usb port plus charging port, and the right one is for a single  device only - including hdmi out.
That is what I was very much hoping. The video left the impression that only the left side was good for peripherals, which was troubling. Very glad the impression I took away was erroneous.
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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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Puzzled about USB configuration
« Reply #3 on: April 11, 2018, 03:08:23 am »
Quote from: depscribe
The video left the impression that only the left side was good for peripherals, which was troubling. Very glad the impression I took away was erroneous.

I also can confirm a curious observation: I got a little USB C hub with ethernet and SD reader (MOKO 7-in-1, https://www.amazon.com/dp/B07872ZC6Y (sorry, did not find an entry on the ‘manufacturer’ website)). Put in an storage device (actually not totally sure right now if it was SD or a pen drive … it was a 1G SD card, pretty sure …) and it was recognized on both sides of the Gemini. It might even work with the Ethernet port! I must admit that I never heard of USB ports that cannot support another USB hub being connected before. Maybe USB 3.0 is fine, but not USB 3.1?

I need to test that claim that at least slow charging might work with some hubs. If slow charging is enough to top up the device eventually with the screen running, that would be fine.
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vader

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Puzzled about USB configuration
« Reply #4 on: April 11, 2018, 05:26:22 am »
Quote from: sobukus
Quote from: depscribe
The video left the impression that only the left side was good for peripherals, which was troubling. Very glad the impression I took away was erroneous.

I also can confirm a curious observation: I got a little USB C hub with ethernet and SD reader (MOKO 7-in-1, https://www.amazon.com/dp/B07872ZC6Y (sorry, did not find an entry on the ‘manufacturer’ website)). Put in an storage device (actually not totally sure right now if it was SD or a pen drive … it was a 1G SD card, pretty sure …) and it was recognized on both sides of the Gemini. It might even work with the Ethernet port! I must admit that I never heard of USB ports that cannot support another USB hub being connected before. Maybe USB 3.0 is fine, but not USB 3.1?

I need to test that claim that at least slow charging might work with some hubs. If slow charging is enough to top up the device eventually with the screen running, that would be fine.
The right usb port is aUSB OTG port and can support only one device (the hub doesn't count). I have used the ethernet port on a satechi hub on the right hand side as well as a joystick and many sd cards/usb sticks. As soon as you connect a second device it stops. The left hand side is a full port and can have several devices connected. I havent got it slow charging yet.
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sobukus

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Puzzled about USB configuration
« Reply #5 on: April 12, 2018, 02:00:09 am »
Quote from: vader
Assoon as you connect a second device it stops.
Challenge accepted. I connected two thumb drives and one SD card to the hub on the right side. For good measure, I also connected the Ethernet. All three storage devices were accessible. The Ethernet port LEDs indicated that it has a link at least. It occured that the music playing from one storage medium stopped when starting to format another. Not sure if that is already a real limitation of the port or a software glitch … or the fact that I gave the hub no external power. I don't have time for more thorough testing now. Maybe you can suggest an operation that is guaranteed to fail with such a port. Of course I can compare the same thing (writing to one storage device while reading another) on the other port …

I'm curious if that really already exceeds what an OTG port is supposed to do. I happen to remember a Nokia N800 connected to a powered USB hub for a keyboard and storage devices. That was also early OTG. I just needed to enable host mode and it was a normal USB port from then on.
« Last Edit: April 12, 2018, 02:00:32 am by sobukus »
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sobukus

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Puzzled about USB configuration
« Reply #6 on: April 12, 2018, 04:09:07 pm »
I was able to verify two more USB hubs that work on the right-side port. With one of them, a power supply needs to be connected to the left-side port or to the hub itself to prevent the Gemini from immediately powering off (probably needs too much juice).

I can read SD cards in the hub-builtin reader and also USB pen drives. Once I test proper Linux, I could check the Ethernet. How come that this works? Is the only issue that the right-side port cannot supply much power? The one that works without extra power, even, is the doedoeflu hub with 3 USB A, PD, HDMI, SD and TF, Ethernet (a very compact package). That is in addition to the simpler hub I indicated before.
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vader

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Puzzled about USB configuration
« Reply #7 on: April 12, 2018, 07:43:37 pm »
Could well be just power. If I connect the ethernet to the right side, nothing else works. I think I need to try harder though  If I could get charging through the hub, then I would be happy. I might have a play today.
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Grench

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Puzzled about USB configuration
« Reply #8 on: April 20, 2018, 06:15:17 pm »
Has anyone tried to:

Left USB C = Planet Computers hub.  Connect to keyboard, mouse, ethernet, charger.
Right USB C = Planet Computers HDMI adapter

Essentially desktop usage mode.

Can it charge through the PC hub on the left port?
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guglielmo

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Puzzled about USB configuration
« Reply #9 on: April 21, 2018, 03:19:18 am »
I've connected my Gemini to a monitor through the hdmi cable and to a mouse and keyboard using the Hub. Worked perfectly, tried with Sentio desktop to figure out the multitasking feature with resizable windows. Just a try, anyway got the impression of a good basic pc replacement for browsing, text editing and mail.
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rgb

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Puzzled about USB configuration
« Reply #10 on: April 26, 2018, 06:41:37 am »
Quote from: Grench
Has anyone tried to:

Left USB C = Planet Computers hub.  Connect to keyboard, mouse, ethernet, charger.
Right USB C = Planet Computers HDMI adapter

Essentially desktop usage mode.

Can it charge through the PC hub on the left port?

I can confirm that it does not charge through the PC hub in the left port. Which means your scenario lacks a power source (and given the increased power drain, means that desktop usage is limited).

Slightly disappointing.
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Grench

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Puzzled about USB configuration
« Reply #11 on: April 26, 2018, 03:07:23 pm »
Quote from: rgb
Quote from: Grench
Has anyone tried to:

Left USB C = Planet Computers hub.  Connect to keyboard, mouse, ethernet, charger.
Right USB C = Planet Computers HDMI adapter

Essentially desktop usage mode.

Can it charge through the PC hub on the left port?

I can confirm that it does not charge through the PC hub in the left port. Which means your scenario lacks a power source (and given the increased power drain, means that desktop usage is limited).

Slightly disappointing.

So - what it needs then is a replacement battery & battery cover to provide wireless battery charging and a charge plate ...  only partially kidding on that.

So, to make it work in a desktop application...
Left USB C to power (power has to exist or this is a fail)
Right USB to HDMI adapter to monitor
Bluetooth Keyboard & mouse.  Finding bluetooth keyboards that don't outright suck is challenging.  I found the Bastron to be loud but functional for my Samsung Galaxy Note 12.2 Android bluetooth tablet:  https://www.amazon.com/Keyboard-Backlit-Blu...d/dp/B077P2DGS3

So - desktop use isn't entirely out of the question, but fully wired desktop use is a fail.
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jornada720

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Puzzled about USB configuration
« Reply #12 on: April 26, 2018, 10:46:24 pm »
Quote from: Grench
Quote from: rgb
Quote from: Grench
Has anyone tried to:

Left USB C = Planet Computers hub.  Connect to keyboard, mouse, ethernet, charger.
Right USB C = Planet Computers HDMI adapter

Essentially desktop usage mode.

Can it charge through the PC hub on the left port?

I can confirm that it does not charge through the PC hub in the left port. Which means your scenario lacks a power source (and given the increased power drain, means that desktop usage is limited).

Slightly disappointing.

So - what it needs then is a replacement battery & battery cover to provide wireless battery charging and a charge plate ...  only partially kidding on that.

So, to make it work in a desktop application...
Left USB C to power (power has to exist or this is a fail)
Right USB to HDMI adapter to monitor
Bluetooth Keyboard & mouse.  Finding bluetooth keyboards that don't outright suck is challenging.  I found the Bastron to be loud but functional for my Samsung Galaxy Note 12.2 Android bluetooth tablet:  https://www.amazon.com/Keyboard-Backlit-Blu...d/dp/B077P2DGS3

So - desktop use isn't entirely out of the question, but fully wired desktop use is a fail.

I apologize if this has been mentioned already but aren't there USB hubs that can provide power and also peripherals?
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thefloyd

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Puzzled about USB configuration
« Reply #13 on: May 06, 2018, 08:06:58 am »
yes, but USB C PD is required to hub+charge and the gemini doesn't support USB PD. I have all but confirmed this with multiple USB C PD chargers (gemini won't charge at all from them) and the gemini hub plus a 3rd party hub each with a variety of PD and non-PD chargers.

The gemini will ONLY charge (no hub) via non-PD chargers. Thus, no PD support. Thus, no HUB+charge under any circumstance I can think of.
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cpitchford

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Puzzled about USB configuration
« Reply #14 on: June 06, 2018, 10:52:19 am »
It's more complex and possibly more buggy than this.

Here's what experimentation has shown so far:

With the Gemini powered on:
  • A regular USB-C charger is not detected
  • A charger connected via the USB-C hub is not detected
However, if you power the Gemini off:
  • Attaching a regular USB-C charger will start charging
  • Attaching the hub and a charger will start charging
  • Powering on the Gemini will boot and continue to charge
  • Disconnecting the charger (or hub) and re-attaching will not resume charging
  • When powered on, it only recognises USB-A chargers (using a USB-A -> USB-C cable) such as the charger that comes with the Gemini
Since it works if booted when attached, it feels like a firmware update would correct this behaviour and allow powered hubs and proper USB-C chargers. At the moment it requires a power off/on to use power alternatives which is a huge shame.

Quote from: thefloyd
yes, but USB C PD is required to hub+charge and the gemini doesn't support USB PD. I have all but confirmed this with multiple USB C PD chargers (gemini won't charge at all from them) and the gemini hub plus a 3rd party hub each with a variety of PD and non-PD chargers.

The gemini will ONLY charge (no hub) via non-PD chargers. Thus, no PD support. Thus, no HUB+charge under any circumstance I can think of.
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