[Replicant] OTG hub with charging?

John Sullivan john at wjsullivan.net
Sun Jan 14 15:08:40 UTC 2018


On January 14, 2018 7:20:29 AM EST, Fil <fil.bergamo at riseup.net> wrote:
>
>On 13/01/2018 22:36, John Sullivan wrote:
>> Hi all,
>
>Hi John,
>
>> Does anyone know of an OTG hub (ideally with 2-3 USB 2.0 or 3.0
>> connections) that can charge the phone/tablet while the other devices
>> are connected?
>
>I just got myself one of those, featuring 3 usb connections and an
>additional charging socket.
>It also features a switch to change between charge and OTG mode, but
>that seems to only apply to devices that actually separate the two
>things.
>I obtained mixed results using it. Read on for more insight.
>
>> I'm looking to use primarily with a Note 8.0 tablet, secondarily with
>a
>> Note 2 phone if it so happens to work. Device wise, I want mainly to
>> connect a USB keyboard and a USB wifi dongle.
>
>I personally tried both of those devices with the OTB hub and this is
>what I learned:
>The fact is that OTG and charging need two different wiring
>configurations (i guess micro resistors with different values are
>involved), and while the cable itself can provide either of them at a
>single time, the possibility to do OTG and charging at the same time is
>device specific.
>I think it has to do with the specific wiring *inside* the device.
>My personal experience is that the Note 8.0 tablet happily charges
>while
>using the WiFi dongle (had to do a couple of attempts with the
>charge-OTG switch but it does work).
>Unfortunately the Note 2 doesn't allow for such a configuration, no
>matter what combination I tried. And I think there's absolutely NO
>chance of having it charge while in OTG mode without changing resistors
>on the board itself.
>
>As a side note, the Galaxy S3 (GT-I9300) can also charge while in OTG
>mode, just like the Note 8.0.
>
>> I've read some commentary that seems to indicate that what I want
>> doesn't exist for safety standard reasons (power only supposed to
>flow
>> one way), but I can't tell for sure.
>
>I tend to believe those are false claims..
>Instead, as I said, it all depends on the specific device design.
>And there's very little one can do if the device's board doesn't
>support
>both modes at the same time..
>
>Hope I've been helpful.
>
>Happy hacking,
>
>Fil

Hi Fil,

Very helpful thanks. Do you have a link to the one you are using with the Note 8.0? Mine does not charge while using the WiFi adapter. Well, I am assuming the charging icon would display - does it display for you? And is your Note 8.0 the GSM model or just WiFi?


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