[General Questions and Answers] MNASWL:
This tutorial is aimed to ones who wish to have USB OTG Capability within their

HTC Desire S ( Saga ).

1: what you need ( software )

A USB host capable kernel or your Android Must support USB Host APIs.

if you don’t have proper kernel you will not get USB OTG support, in my case

I flashed kernel 3.0.76 from Stefan on ics Final v2.0 ,Android version 4.0.4, sense 3.6, Now there is another kernel, I have Hboot 2.0******.

Available with USB Host capability the version is 3.0.89, I have not tried this kernel

Yet, you can if you wish, you can find both of these kernels at XDA.

If your rom or framework does support USB Host APIs then may be you don’t need to flash

The kernels.

With a linux patched kernel USB devices are detected under “ sys\bus\usb\*.* “.

If your android system and framework supports USB Host APIs, Android will detect USB devices

Under “dev\bus\usb\*.*”

Install USB Device info from google play store.

Install USB Host Diagnostics from Play Store.

Install USB OTG Helper from Play Store or any other software like Stick Mount to mount your USB STORAGE DEVICE.

You must have root access and super user installed.

Before flashing the kernel always make a backup of your current Rom.

As in my case when I flashed the kernel my wi-fi stoped working and then I had to manually push some wifi related files to system directory.

2: Hardware

You need a USB OTG Cable, unfortunately USB OTG cables available in Market are not suitable for Desire S, because Desire S does not Power the USB Bus within its own, to wake up USB Host Capability for Desire S we need to short Pin 4 and 5 at Micro B plug, Micro B female is incorporated within Desire S.

If a cable with shortened pin 4 and 5 is available then you don’t have to make a cable.

Its recommended not to short pin 4 and 5 at micro B plug, its good to sold a 10k resistor between pin 4 and 5. Get a standard charging cable for you Desire S with Micro B Plug, First of all check this cable by connecting it to your computer, if charge only and disk drive options appears at your phone the cable is good for our purpose.

Secondly get one Standard USB Extension cable, this cable has 4 pin Male at one end and 4 pin Female at the other end. Cut this cable from the center, remove the shielding plastic and uncover the wires.

You will find four wires,

Red = POWER ( Normally 5 Volts )

White = ( Data- )

Green = ( Data+)

Black = GND ( Reference Ground for 5 Volts )

Get a soldering iron and a piece of solder wire.

Now pick Male end, cut white and green wires ( we don’t need them because we only need power wires from this plug ).

Now pick Female one, uncover the wires from this also, Make a joint of Male “RED” with Female “RED”, and Also Make a Joint of Male “BLACK” to Female “Black”, don’t cut “WHITE” and “GREEN” wires.

Now cover “RED” and “Black” with some sort of Glue or Adhesive Tape, Glue is better choice because it will prevent the wires from getting short, or you can use heat shrinking sleeve.

Now pick your standard charging cable and cut it from the center and hold the end having small Micro B Plug, uncover plastic shielding, you shall find following wires,

RED

WHITE

GREEN

BLACK

Now get the cable you already mad having Standard Male and Female and Make joints as follows.

RED = RED

WHITE = WHITE

GREEN = GREEN

BLACK = BLACK

Double check all connections and now the important part comes

Gently remove the plastic from behind the Micro B plug with sharp knife or cutter, be careful and be patient here because in a hurry you can damage the plug or wires.

After you remove the covering Micro B plug you will find “ RED , WHITE , GREEN , BLACK “ wires soldered.

Notice that only one point at Micro B plug is Empty, There you go, it is pin No 4 of Micro B Plug.

You will also see “BLACK” wire there, Now get your 10 k resistor, sold one end of the resistor to where the “BLACK” wire is soldered and sold other end to pin No 4 which you have already found empty.

Be careful here not to short any pins, it may lead to a disapointment. Your USB OTG CABLE is ready, put some glue where you find its necessary to cover and also over the Micro B plug from where you remove the plastic.

Now run USB Host Diagnostics and when it says to plug in then plug your micro B connector to the phone, you don’t have to apply power through mail connector until. USB Host Diagnostics should show

As following picture, it will detect USB root hub of the phone, if it does not detect anything then

May be there your cable is not prepared properly, or just Restart your phone after installing USB HOST Diagnostics and check again, USB HOST Diagnostics needs root access if USB HOST APIs or framework is

Not supporting USB HOST MOD.

Now apply power through your charger to MALE connector, after 5 or 7 seconds your phone will indicate charging, means the cable is correct.

Put a USB stick in USB Female connector, open USB OTG Helper and hit MOUNT, it will mount your USB storage device and will create a directory at the root of your SD card named “UsbOtgDrives”.

You can brows the files and directories of your device in that folder.

Un mount USB Mass storage through USB OTG Helper and connect any USB mouse and you will see a small cursor, its very small and but you can locate it, if pointer does not appear remove the power plug and connect again, same way you can connect a USB keyboard, connect a USB keyboard and open any text editor in your phone and check by typing from keyboard or open your sms editor and check it there.

You can get your device info with “USB Device Info” if you installed it from play store.