USB C with OTG with charging: Portables as Computers in 2019 and on

[JamesMNewton]

I'm seeing multiple kickstarters for "turn your cell phone into a computer" type appliances. Typically a keyboard thing that includes an OTG adapter, an HDMI output, etc... Most /claim/ that you can charge your cell phone while working. They are all overfunded (and shaky, I'm not recommending them)

I've tried many times to use phones / tablets as OTG devices to interface to hardware of different types. Everything from diagnostic tools to robot arms (no really, I'd post links but I'm a newbie here and linking is always suspect; I don't want to be accused of spamming).

One major issue always comes up: You can NOT charge while running OTG on /most/ phones. I've done a lot of research on this, and found a few older phones / tablets that seem to support it. I can't find a /single/ USB C based device that is known to do it. Perhaps it's just not an advertising point? MFGRs don't see most users doing that, so they don't support it?

So what am I asking?
1. Is anyone with a modern phone, especially USB C based, actually using OTG and charging at the same time? Please note: I'm NOT talking about charging the OTG device /from/ the phone, I'm talking about charging the phone while using OTG devices. If you are doing this, please: What phone, what OTG adapter?

2. Is this something people have an interest in doing? Why yes, why no? For me, I don't have any interest in using my cell as a computer, but being able to plug it into equipment and monitor / control operation while not running the battery flat would be great!

3. Is anyone aware of the actual specs, technical issues, reasons for the current state of affairs? I've started a web page to track this issue (again, not linking, not spamming) and would love to hear from anyone with direct knowledge of the technical issues involved. Why doesn't it always work? What specification needs to be met? What future is there for this sort of feature?

Here are the devices I understand DO support it:
RaspBerry Pi
Amazon FireStick
Amazon Kindle Fire 10???
Dell Venue 8 pro
HTC One M9
Lenovo Miix 2 tablet?
Lenovo Yoga Book
Moto G 4?
NuVision Tab 8 (Windows 10) after restart only?
Nvidia Shield K1 table??
OnePlus One
Samsung Galaxy S3
Samsung Galaxy S4
Samsung Galaxy S5
Samsung Galaxy Note 3
Samsung Galaxy Tab A7?
Samsung Galaxy Tab A8.0
Samsung Galaxy Tab S2??
Samsung Galaxy Tab S 10.5?
Samsung Galaxy View
Snes Classic

And here are some that support OTG, but will not charge at the same time:
Amazon Kindle Fire 7
Asus T100TAM
LG Nexus 5
LG Nexus 7
Samsung Galaxy Note 4
Samsung Galaxy S7
Samsung Galaxy S8+
Samsung Galaxy S9
Samsung Galaxy TabPro 10.1

Please do add on your info?

 

[Prostheta]

How's the research going? I've been looking for tabs that support USB-OTG and charging when connected to a powered USB hub as I'm planning a car install. Sort of interested in whether the newer tabs like the Samsung Tab S5E support this or not. That would be sweet installed into the dash!

 

[Droidriven]

How's the research going? I've been looking for tabs that support USB-OTG and charging when connected to a powered USB hub as I'm planning a car install. Sort of interested in whether the newer tabs like the Samsung Tab S5E support this or not. That would be sweet installed into the dash!

..



Sent from my SM-S767VL using Tapatalk

 

[Prostheta]

I decided to buy a Galaxy Tab A 10.1 2019 (SM-T515) and will report back with findings once I test with a USB C OTG Y cable adapter. It's possible that I may need to fabricate some discrete switch into the tablet's USB to alternate between OTG and charging. Not an ideal state of affairs.

Additionally, I've pondered whether devices with pogo pin dock connectors such as the Samsung Galaxy Tab S5E can charge that way whilst using the USB port for OTG devices. Whilst not strictly meeting the requirement of the list (one USB port charging whilst using OTG) it does present a compelling alternative.

 

[Prostheta]

It seems that with USB C, the "standard" includes OTG host charging but called pass through charging, dual role data or something along those lines. I connected my Tab A 10,1 to a Kingston Nucleum non-powered hub via the connected USB C lead, then plugged in a charger to another USB C port. Charging! Pretty much the same works whichever combination of connections is used. It seems the devices negotiate who is the power delivery and at what level. There are some settings in android to set also.

 

[Droidriven]

It seems that with USB C, the "standard" includes OTG host charging but called pass through charging, dual role data or something along those lines. I connected my Tab A 10,1 to a Kingston Nucleum non-powered hub via the connected USB C lead, then plugged in a charger to another USB C port. Charging! Pretty much the same works whichever combination of connections is used. It seems the devices negotiate who is the power delivery and at what level. There are some settings in android to set also.

Yes, but does it charge while also having other external devices such as a USB hard drive connected to the hub(which also requires being powered) at the same time? The USB hard drive receives power from the hub like it should and the device charges simultaneously?

Sent from my SM-S767VL using Tapatalk

 

[Prostheta]

I've tested with a USB mouse dongle, and when it arrives, my Meizu DAC pro. So far it seems positive. It does however default to the 5v charging level, but that's fine.

 

[jivenene]

I've tested with a USB mouse dongle, and when it arrives, my Meizu DAC pro. So far it seems positive. It does however default to the 5v charging level, but that's fine.

Hey did you ever get this working? Does USB-C charge and connect devices simultaneously?

thx

 

[Prostheta]

Yes, everything works fine....sometimes. The Kingston Nucleum USB C hub has a 5v supply plugged into a 12v car charger port that has USB PD and QC3.0 options. The tablet is problematic in that once the power to the charger (and hence the hub) is removed after turning the car off, the tablet decides that it'll take over the role of supplying power to the hub which discharges the tablet battery whilst the car is off. Also, the hub doesn't always arrange the attached devices correctly, leaving the USB SSD unmounted and the tablet sat alone charging. I'm unsure what is happening, however I'll blame USB C for being a dumpster fire.

 

[jivenene]

Yes, everything works fine....sometimes. The Kingston Nucleum USB C hub has a 5v supply plugged into a 12v car charger port that has USB PD and QC3.0 options. The tablet is problematic in that once the power to the charger (and hence the hub) is removed after turning the car off, the tablet decides that it'll take over the role of supplying power to the hub which discharges the tablet battery whilst the car is off. Also, the hub doesn't always arrange the attached devices correctly, leaving the USB SSD unmounted and the tablet sat alone charging. I'm unsure what is happening, however I'll blame USB C for being a dumpster fire.

Thanks, I've been looking for a tablet for car infotainment and gauges/data logging, finally decided on a Lenovo tab 4 8 plus Verizon model, precisely because it had a USB-C 3.0 port, and it is rootable. Then I started reading about the complicated mess that the USB-C standard is. Anyway I'll make a post in the General Discussion>Connected Car forums in a month or so when I get everything connected... work and kids always stand in the way of progress

 

[Prostheta]

Is that the place to discuss these things? I've had a lot of difficulty trying to find the best place for this, as most are either too specific or not quite on-topic.

 

[Prostheta]

I'm updating all of my comments in various threads on this. I've found that with my specific setup with the Kingston Nucleum hub, there are issues. I'm unsure as to the cause, but hey. Firstly, the tablet needs to be powered up before I turn on the car or at least supply power to the hub. It seems that if this is done the other way around, that is, to power on the car accessories (and hence the hub) then it seems to end up staying as the "device in charge" of the USB network. The tablet charges (slowly) but doesn't mount the USB SSD drive or the USB DAC. If the tablet is powering the hub (in charge, so to speak) then applying power to the hub via the car accessory supply has it working as expected. This does mean that the tablet ends up with a power drain when the car/USB power supply is powered down which isn't ideal. I've gotten into the habit of turning the tablet off when I park for long periods of time, however I need to boot it up to "take charge" of the USB hub network before I can start the car. It's a bit of a bummer.

 

[SGH-i200]

It seems that with USB C, the "standard" includes OTG host charging but called pass through charging, dual role data or something along those lines.

Yes, my notebook has an USB-C port and can be charged via USB-C PD pass trough by a USB-C dock (USB hub with LAN). Why the Android Smartphones/Tablets don't do the same?

3. Is anyone aware of the actual specs, technical issues, reasons for the current state of affairs? I've started a web page to track this issue (again, not linking, not spamming) and would love to hear from anyone with direct knowledge of the technical issues involved. Why doesn't it always work? What specification needs to be met? What future is there for this sort of feature?

I found this diagram of a "accessory charger adapter" (USB 2.0 spec, not 3.0+?): https://superuser.com/questions/1124237/windows-tablet-otg-simultaneously-charge/1124354#1124354

Supports OTG, but will not charge at the same time:
LG Nexus 7

Charging+OTG was possible on Nexus 7 2012+2013 using a custom kernel!

 

[Prostheta]

Yeah, the Nexus 7 was one of the rarities amongst pre-USB3.0 spec ports that could be manipulated into simultaneous data and charging.

My ongoing concern is with ennumeration; I can get my Tab A10,1 charging through the hub easily. However, to access devices attached to the hub, the tablet needs to be active first and then power applied to the hub. Applying power to the hub first, then starting the tablet leads to charging only. The problem as I see it is the negotiation over host rights on a USB network, and whether re-negotiation or forcing priority is possible. It could be a hardware issue built into the USB-PD negotiation specs, a hardware issue with the tablet or simply a software issue in the tablet. I'm not really wanting to wade into the USB specs since they're notoriously vague and contradictary these days....

 

[SGH-i200]

It does however default to the 5v charging level, but that's fine.

I would want to know why? It was the same with the Pixel C, but Notebooks will charge at faster speed via PD pass through.

I tried powering the PixelC and it works but not at the same speed as the same charger connected directly. I estimate about 1-1.2A

PD charging of a Pixel 1 via pass trough (interesting read on PD negotiations):
"The USB Power Delivery behavior seen when the Plugable USB-C 3-Port Hub is passing through power from Google Pixel's own USB Power Delivery charger is a lot different from what you get when you plug the charger directly into the Google Pixel." https://gtrusted.com/review/how-the...google-pixel-phone-using-usb-power-delivery-2

 

[SGH-i200]

You can NOT charge while running OTG on /most/ phones. I've done a lot of research on this, and found a few older phones / tablets that seem to support it. I can't find a /single/ USB C based device that is known to do it. Perhaps it's just not an advertising point? MFGRs don't see most users doing that, so they don't support it?

I was able to use the ethernet, PD pass through and USB host feature at the same time with:
1. Samsung Galaxy Tab A 10.5 2018 (Stock ROM)
2. Google Pixel 2 (LineageOS 17.1)

The USB-C standard really has made things easier! I was not able to use the HDMI output because these devices do not support DP alt mode! :-(

"USB C Charger RAVPower 65W Fast Wall Charger, PD3.0 & GaN Tech 2-Port Power Adapter" https://www.amazon.com/Charger-RAVPower-Adapter-Compact-Foldable/dp/B08MWG612F

"Dockteck 4-in-1 USB C Hub with 4K@60Hz HDMI HDR, 100W PD, USB 3.0 and Gigabit Ethernet, Multiport USB Type C Adapter"

Amazon.com: dockteck 4-in-1 USB C Hub with 4K@60Hz HDMI HDR, 100W PD, USB 3.0 and Gigabit Ethernet, Multiport USB Type C Adapter for MacBook/Pro/Air, iMac, XPS, iPad Pro 2020 2018 and More: Computers & Accessories

Amazon.com: dockteck 4-in-1 USB C Hub with 4K@60Hz HDMI HDR, 100W PD, USB 3.0 and Gigabit Ethernet, Multiport USB Type C Adapter for MacBook/Pro/Air, iMac, XPS, iPad Pro 2020 2018 and More: Computers & Accessories

www.amazon.com

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Vendor Name (from DB): Genesys Logic, Inc.
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[mbquartiano]

"Charging+OTG was possible on Nexus 7 2012+2013 using a custom kernel! "

Actually You don't need to modify anything with certain tablets to do otg and charging at the same time:
I bought a Lenovo tab 8 hd and only by using a so called "charging y cable" (please Google it) I was able to listen music through my USB dac and charge the tab simultaneously.
Maybe getting into developer mode helped? I don't know, but it's so easy to try...
Daniel