[Android Software/Hacking General [Developers Only]] plopper:
= DIY usb hub for HTC =

== Warning ==

First of all, your using this manual at your own risk, I don't take any responsebilety for your actions.

If you make a mistake you risk blowing up your phone usb port, or even burning out the phone completly.

I have a background in electronics and was age 12 when I did my first hardware mod on a computer.

I knew the risc I was taking when I started this mod, an I accepted it.

The included pictures are just for reference, do not use them as a guide, your board will be different.

If you happen to use the same usb hub, then also use the same connection points.

== Introduction ==

Unlike the Y cable this mod leaves all usb ports available, but it renders the usb hub useless for normal use.

It's gone be purely for use on HTC phones which DO NOT supply power to the usb port, check your phone before you start building.

== The parts ==

For this project we need the following parts.

* 4 port usb hub (this may be a active/powered hub, but those mostly have a to weak powersupply).

* micro usb cable.

* powersupply of 5V and at least 2000mA.

* half a liter of fresh coffee or energy drink.

== Power ==

A standard usb port of a computer supply's 5V with 500mA, so for a 4 port usb hub we need 4x the current, making the 2000mA.

But as the phone also needs at least 500mA, we need a bit more power, totaling 2500mA, alltho there is some wiggleroom here.

A keyboard/mouse hardly ever need the full 500mA, so we can steal a bit from that.

The powersupply i used gives out 2250mA, and using the above wiggleroom it leaves about 700mA for the phone.

== The internals of the hub ==

When we open the usb hub were gone find something like the next picture.

This is my finished hub so ignore the black and red wires for now.

Look for the green and white cables and imagine the red wire above them and the black under them.

The green and white cables are the data cables.

Cut of the standard usb plug from the micro usb cable, and connect the green and white cables to the same points as the original cable from the hub.

If your hub has a connector instead of a cable, the white cable goes beside the red wire (positive), the green beside the black (negative).

This is visible on the pictures.

If you have any doubt, then skip to the next step and come back after it.

Once you have figured out the powerlines this step will become clear.

== Finding the power lines ==

Originaly the usb cable powers the controller and sends the left over power to the ports, making the hub able to power low power devices like keyboards and mice.

This is why we have the wiggle room on the power supply.

So first we have to locate the power lines on the board as outlined on the next picture.

Red is the positive path, blue the negative path.

Look for the negative path first and you'll find the positive in no time.

An easy trick is to start look at the usb ports.

You'll see that 1 of the 4 pins is connected to the ground of the port, thats the negative pin/track.

the oposite pin of the 4 is the positive (the data pins are the 2 middle pins).

== The power protection ==

Now if you look carefully you can see 2 gaps in the positive path (red collor), those are there because of the protection needed when pluging in the external powersupply.

And the fact that the controller gets power from 2 locations.

They are located in the yellow circles on the next picture.

== Bypasing the power protection ==

But as the phone doesn't supply any power on the usb port, in fact it needs power, were gone have to bypase (easier then removing it) the protection.

This is fairly easy, just connect the points which normaly go to the usb cable which connects the computer to the points of the external powersupply.

The connector on my hub is located right beside the protection diode on the right side of the board.

== Rerouting the power to the phone ==

Next step is to give the phone power in the same way.

To make it easier I used 1 of the usb ports for this.

Safes the hassle to connect 2 cables to the small connection points.

== Putting the hub back together ==

Now we can put the hub back into it's casing.

== The finished project ==

And we end up with a special usb hub for our phone.

Like it was bought this way.