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Understanding a USB Hub

Posted: Sat Jun 18, 2016 12:14 am
by Kilren
Bought a micro usb hub. It is really nice because it is tiny. Almost small enough that soldering is difficult.
Amazon USB hub
[spoiler="Amazon Product Description"]Support data synchronize when charging For Galaxy S4 , Note 3 (Switch on "Charge")
Micro USB cable support charging via USB wall/car charger, laptop PC etc.
Intelligent power protection circuit,anti-overcharge and anti- overheat included.
Quick, easy connection and rapid synchronization.
OTG port provides a simple way to connect phone to a USB capable computer for data synchronization and file transfers. (Switch on "OTG")
Color: Black[/spoiler]
It does work with RPi. Now for the durability test...

One really interesting piece though is that it has a OTG/Power female micro usb that is toggled by a switch (I believe a DPDT). My question is pretty much summed up like this, is it truly a 4 USB hub, or is it clever marketing for a 3 USB hub?

The reason I ask is once I opened it, instead of having 5 wires like I expected, it only had two (the picture shows + still there. I ripped off - by accident getting it out of the case). This really confused me. Can it be a 4 USB port hub with the right wiring? What is that wiring?

Last question, I want to remove the DPDT switch and bridge the solder holes to permanently be in the OTG position. How do I do that (which holes am I soldering a bridge to?)
Image

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 6:13 am
by DirtyBullets
Don't see why not, i mean it looks very simple to solder to, or you can use the wires it came with instead of adding your own, my guess about the OTG and switch is to reverse the power but im not sure about this as it seems odd to have it like this,

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 7:46 am
by Helder
It's a 3 port hub with one being an alternate way to power/ charge what's connected. You only see the red and black wires so that's only power which is why the data is cut off when you switch to charge mode.

Can you show the reverse side of the board? I'd like to see what they're using for circuitry.

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 2:40 pm
by Kilren
Helder wrote:It's a 3 port hub with one being an alternate way to power/ charge what's connected. You only see the red and black wires so that's only power which is why the data is cut off when you switch to charge mode.

Can you show the reverse side of the board? I'd like to see what they're using for circuitry.
So, that fourth cable is capable of data? The pictures on amazon hints that it can (they show four peripherals plugged in). How would I remove the switch and bridge it so it's permanently stuck on otg?

Working on the pictures.

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 2:56 pm
by Kilren
@Helder

Image

IC chip reads:
FE1.1S
USB 2.0 HUB
I53J450A9H031 (might be wrong slightly, very difficult to read because of incredibly small size and I have glue pieces on it now. ???J450A9H031)


[spoiler="This thing is tiny. Posted one more pictures just to realize just how small it is."]Image[/spoiler]

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 2:58 pm
by Helder
Kilren wrote: So, that fourth cable is capable of data? The pictures on amazon hints that it can (they show four peripherals plugged in). How would I remove the switch and bridge it so it's permanently stuck on otg?

Working on the pictures.
What I mean is that last port looks like it only has power so I doubt it can have data in it, once I get to see the whole board we can see exactly what it does or can be modded to do.

Edit:
That's the same chip I'm using in the USB Hub part of my WIP all in one board so that can definitely do 4 ports but it seems it's only wired for 3.

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 3:04 pm
by Kilren
Helder wrote:
Kilren wrote: So, that fourth cable is capable of data? The pictures on amazon hints that it can (they show four peripherals plugged in). How would I remove the switch and bridge it so it's permanently stuck on otg?

Working on the pictures.
What I mean is that last port looks like it only has power so I doubt it can have data in it, once I get to see the whole board we can see exactly what it does or can be modded to do.

Edit:
That's the same chip I'm using in the USB Hub part of my WIP all in one board so that can definitely do 4 ports but it seems it's only wired for 3.
That is where my confustion is. The switch is between power/OTG. The pictures on amazon also indicate that it can have 4 peripherals plugged in. I don't think there would be a switch between power/power.

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 3:11 pm
by Helder
Ok so looking at that board I can see when the switch is up there is power going to the whole circuit and the last port (the 2 wire port) isn't even receiving power then when the switch is down only that 2 wire port receives power and the rest of the circuit isn't active.

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 3:13 pm
by Kilren
Helder wrote:Ok so looking at that board I can see when the switch is up there is power going to the whole circuit and the last port (the 2 wire port) isn't even receiving power then when the switch is down only that 2 wire port receives power and the rest of the circuit isn't active.
So are those two cords (+/-) power only then, or are they switching between power/data?

Re: Understanding a USB Hub

Posted: Sat Jun 18, 2016 3:15 pm
by Helder
That last port is power only and like I mentioned above is either active and receives power or is inactive and does nothing since the switch cuts off power to it.