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I made a USB dongle that plugs into the USB port on the touchpad and provides a powered female USB-A port. It is basically a portable USB charger/battery with an OTG cable soldered to the USB port. Attached is a quick pdf showing the process. It's much smaller and more portable than using a y-cable and powered hub or battery pack.
The charger is $13 on Amazon with free prime shipping and OTG cables around $2 on ebay.
It's nice because it's small and I can secure it to the my case with a rubber band, providing a quick connection to a keyboard/mouse or usb flash drive. The particular charger charges via any powered USB port with a provided cable.
This is the battery pack I ordered, note the picture on the amazon page is not 100% accurate:
http://www.amazon.com/T-Mobile-Port..._1_1?s=wireless&ie=UTF8&qid=1325984238&sr=1-1
This is the cable I purchased, there are cheaper ones, but they ship from China:
http://www.ebay.com/itm/Micro-USB-O...ccessories&hash=item1e69fbb3c5#ht_1336wt_1398
Would that be powerful enough to power external portable hard drive like WD Passport?
gedas5 said:
Would that be powerful enough to power external portable hard drive like WD Passport?
Click to expand...
Click to collapse
Unfortunately, I don't have the power specs on the battery pack. If I come across a USB-powered hard drive, I'll test it.
scarletwahoo said:
I made a USB dongle that plugs into the USB port on the touchpad and provides a powered female USB-A port. It is basically a portable USB charger/battery with an OTG cable soldered to the USB port. Attached is a quick pdf showing the process. It's much smaller and more portable than using a y-cable and powered hub or battery pack.
The charger is $13 on Amazon with free prime shipping and OTG cables around $2 on ebay.
It's nice because it's small and I can secure it to the my case with a rubber band, providing a quick connection to a keyboard/mouse or usb flash drive. The particular charger charges via any powered USB port with a provided cable.
This is the battery pack I ordered, note the picture on the amazon page is not 100% accurate:
http://www.amazon.com/T-Mobile-Port..._1_1?s=wireless&ie=UTF8&qid=1325984238&sr=1-1
This is the cable I purchased, there are cheaper ones, but they ship from China:
http://www.ebay.com/itm/Micro-USB-O...ccessories&hash=item1e69fbb3c5#ht_1336wt_1398
Click to expand...
Click to collapse
that looks nice.. but you re saying that its plug and play?..
you dont have to mount/unmount?
why didnt you get one w/ more usb ports?
your pics are clear.
i wonder how easy it is to do the battery hub like yours but w/ 4 usb ports
Nicely done, very good solution and tutorial. again excellent!!!!
amkaos said:
that looks nice.. but you re saying that its plug and play?..
you dont have to mount/unmount?
why didnt you get one w/ more usb ports?
your pics are clear.
i wonder how easy it is to do the battery hub like yours but w/ 4 usb ports
Click to expand...
Click to collapse
http://www.amazon.com/Solar-Powered-Battery-Charger-Adapter/dp/B006DVMW92
This hub has 4 ports, a battery plus solar charging. That said, if I buy it I'll probably just plug it directly into the OTG cable rather than solder them together. Then again my soldering can be a little rough.
- Sent from a Prime terminal using a friends account
So can we only use the Micro Usb OTG host to connect to a USB drive/keyboard?
tpcm said:
So can we only use the Micro Usb OTG host to connect to a USB drive/keyboard?
Click to expand...
Click to collapse
yes plus 10char
Deserves sticky, love mods like this even if not always practical.
Cant believe they didnt give the touchpad a powered usb host. I guess they figured people would have issues with not enough power or drain the battery too quick with it.
So I think when I have some spare time I may mod your mod and show how to make a powered usb host that plugs into the wall charger so when your "docking" somewhere to charge you can hook up a keyboard and use it without restriction and even be charging the touchpad at the same time.
Probably don't even need to be too creative a proper Y cable may do the trick out the gate. Just to track one down.
Probably a stupid question, but it wouldn't be my first one...
Could you simply use a USB male-to-male cable to go between the battery pack and the OTG cable? Eliminate the soldering that way?
Or am I missing something?
I found a cable that I think will work perfectly for my idea of doing this from the charger instead of from battery: http://www.dealextreme.com/p/usb-fe...gb-tf-card-card-reader-kit-for-xtc-clip-82289
You can do it much cheaper with adapters and a regular y adapter though, and you may want to do so, so that you can have a longer cable from the charger to the y split, but yeah I will try this out sometime soon and let you know how it works.
The charger probably gives enough power to easily run things like a external HDD and such while the battery pack may not.
@Vicious ... couldn't that possibly put too much power to a USB device? Just saying since it is probably meant to be hooked up to a regular USB 5v port and (I don't know the specifics but) the touchpad USB power adapter has a high AMP output (might be talking sht here).
Nothing to worry about a device only "pulls" the amperage it needs so you can have extra with no harm to the device. It is the voltage that needs to match and usb is standard 5v.
Having too little amperage can actually cause a device harm due to malfunction, like a head crashing on a 2.5" hdd during use or a thumb drive failing to flash properly corrupting a sector.
I feel anybody that uses the touchpad in a docked setting that wants to use a keyboard may very well make use of my idea, that I of course got from the OP's idea.
I'll part it out for the cheapest way to make it without any cutting/soldering and test it soon enough.
mountaindewmi said:
@Vicious ... couldn't that possibly put too much power to a USB device? Just saying since it is probably meant to be hooked up to a regular USB 5v port and (I don't know the specifics but) the touchpad USB power adapter has a high AMP output (might be talking sht here).
Click to expand...
Click to collapse
That cable will work fine. I wasn't doing anything special, only eliminating the y-cable. I mainly wanted a small form factor way of adding a USB port to my case for portability. Now I can put a movie on a usb drive and watch it on the go.
You generally don't have to worry about using a supply that is to powerful. As long as the voltage output is 5 V, the device will only draw a certain current and consume the corresponding amount of power. The rating on a constant voltage supply is simply the maximum current it can provide, the amount it provides depends on the properties of the device.
Say you have a device, it states it operates at 5 V and draws 100 mA of current. That means the impedance of the device is R = V / I = 50 ohms. So if you use a 5 V supply rated to at least 100 mA, the device will only draw 100 mA. The supply can be rated for 100 mA or 1000 amps, it does not matter. (Although you wouldn't want to use 1000 A source as if something breaks or shorts it can draw a higher current)
Wikipedia "ohms law" if you are not familiar.
I tried to do this but can't get it to work, the touchpad shows the charging battery icon only it's not charging, and running dmesg it say source=charger mA=100 and usb otg exited low power mode and then right after says it entered low power mode... Not sure what the issue is...
edit: I'm thinking it may be my soldering work, gonna give it another pass...
joenathane said:
I tried to do this but can't get it to work, the touchpad shows the charging battery icon only it's not charging, and running dmesg it say source=charger mA=100 and usb otg exited low power mode and then right after says it entered low power mode... Not sure what the issue is...
edit: I'm thinking it may be my soldering work, gonna give it another pass...
Click to expand...
Click to collapse
You may have the two data pins shorted together. To the best of my knowledge, this tells the touchpad to go into charging mode. The touchpad charger does this, because in order to charge, it must draw more power than USB ports are designed to provide.
You need to remove the two resistors circled in the PDF. These keep the data pins shorted together as well.
This is a really great idea I think I might try it and your tut is very well explained thanks for taking the time out to put it all together
Thanks
Mouse works fine, keyboard hasn't been tried yet. How do you access a flash drive through this? What are the steps?
If you just cut out the resistors in the battery hub, could you just use the TP's regular cable to plug into one of the ports on the hub?
tpcm said:
Mouse works fine, keyboard hasn't been tried yet. How do you access a flash drive through this? What are the steps?
Click to expand...
Click to collapse
Stick mount works great
Sent from my CM9 TouchPad
If you are traveling and need to use GPS, but maps are loaded on a external card and you have your viewpad charging on lighter outlet.
or (my case) you have some serious amount of text to write and you need the keyboard connected as well as your wall mount charger....
Is there any known way to connect the battery charger and a peripheral as keyboard or usb mass storage device at the same time?
I'm thinking about some surgery to the usb-to-miniusb converter that I use to connect my desktop type keyboard to the viewpad, but don't know what could happen to the usb device or the keyboard. Neither know which of the 5 pins (contacts) of the charger is the active one...
Any suggestions?
Tnx in advance.
anothe question....
Ok... since there is no answer over 24hrs, I'll make another question to make this a little more interesting for you people could help me...
Is there any chance to connect a keyboard (already working) plus a SD card at the same time??
I'm making some fun stuff with a keyboard and making some surgery I could install some kind of "external USB Port" on the keyboard.... but, should it work?? I mean, keyboard and flash memory together, connected to one-single miniUSB port....
Developers.... any suggestion??
Thnx again...
Forgett to say.... on Viewpad7 with FROYO 2.2.1
Another idea
Ok, easy people... That bunch of comments about my topic make s me feel kind dizzy...
Just kidding....
Making some research (on goggle, haha!!), I've found that USB port on a pc have a 5volt-500mA output... So, if that's nominal out and that power could charge the viewpad AND don't turn on smoke any peripheral, Then I just have to connect power out on a wall-mount charger to the 1st pin (wire) of a 5 contact miniUSB, regarding on the power out put on 500mA.
(thanks isIran for your assistance )
now... PLEASE SOMEONE STOP ME IF I'M HAVING SOME IDIOTIC, TABLET BRICKING, IDEA!!!!
Thnx again
Hi,
The Viewpad wall charger have a non standard conector, if you look in the contact part you will see double connection.
In the main charger body you will find the pinout:
Pin 1 & 6 +, pin 5 & 10 -
These pins (6&10) are longer than the data pins to ensure that the power connections mate first and un-mate last.
The wall charger is 2 A and the USB PC port only 0.5A (0.9A for USB3)
For this reason a wall charger change in 2 hours and a PC USB in 15 hours.
A dedicated USB charger should short the 2 data lines together. The device will then not attempt to transmit or receive data, but can draw up to 1.8A
for this reason the device know when it's connected to a computer or to a dedicated charger (like a Garmin GPS)
Probably modifiying a connector (or keyboard) to provide energy and data will work.
Did you try a USB hub?
Less us know the result of your experience.
cheers
You could solve the keyboard problem by using a bluetooth keyboard and you can charge the tab on the USB port at the same time.
ecossais said:
You could solve the keyboard problem by using a bluetooth keyboard and you can charge the tab on the USB port at the same time.
Click to expand...
Click to collapse
Right, this solve one problem, but is much expensive and less fun... Besides, didn't solve the flash drive plus charger issue...
About pins 6 &10... Just noticed that (in over a year never look that closer the charger pin).
I'll try usb hub, but I'm afraid to burn some flash drive or worst...
Thanx for your interest and helpful advice...
Anyone know about a splitter that will take the 30-pin input and let you use one side for the 30-pin power adapter and the other side for 30-pin accessory like USB OTG pigtail?
I'm in the same boat,
Search and search but nothing,
You get USB to 2 30-pin but nothing for 30-pin to 2 30-pin adapters
The only option you have is to buy a Galaxy Tab break out board from Kinetica and solder your own cables to it..
What do you want to use at same time?
It would be nice to run external power while having an accessory plugged in such as the SD or USB drive or keyboard. I have 2 USB keyboards that have the pointing device built into it.
look in m y post in the make your own cables thread.
i added power to the odks circuit board and can watch movies via hdd at same time as charging.
easier way would be use the breaK out board though..
I have the connector parts, just I have to know the pin assignments...
http://forum.xda-developers.com/showthread.php?t=1155065&page=11
Look at this thread..
Try my post first one before this page..
It explains it..
pin 7 is the posative 5v @2amps...
pin 30 is the earth..
(this is how i run it in car connected to 2 amps 5v source)
works well and if start close to 100 percent battery power leave it plugged in it doesnt drop anything even after watching 4 movies in a row still is 100 percent.
eventually i disconnected it to let the battery drop down alittle as not sure if good to keep it at full charge?
Maybe the best way would be try to follow my dock mod?
that way you can just use the 30 pin usb adapter and add a powered hub.
havent given an update on "line out" output as my usb adapter is covering it up
the outlet socket.might consider opening it up again and finding out if works then relocate the 3.5 stereo socket outlet.maybe could just solder some wires to it inside and add a new output some where else more accessable..
This is a bit of an old thread, but thought people might like to know that I have found a solution! DealExtreme has a splitter that has 2 OTG connectors and a charging connector....
3-in-1 30 Pin Male to USB Female OTG Hub Cable for Samsung Galaxy Tab - Black + White
http://dx.com/p/3-in-1-30-pin-male-...ble-for-samsung-galaxy-tab-black-white-153246
Here is the link to the cable post .
http://forum.xda-developers.com/showthread.php?t=1155065&highlight=cables
ToastyZ71 said:
This is a bit of an old thread, but thought people might like to know that I have found a solution! DealExtreme has a splitter that has 2 OTG connectors and a charging connector....
3-in-1 30 Pin Male to USB Female OTG Hub Cable for Samsung Galaxy Tab - Black + White
http://dx.com/p/3-in-1-30-pin-male-...ble-for-samsung-galaxy-tab-black-white-153246
Click to expand...
Click to collapse
Havent seen that cable before...anybody tried it?
Just curious IF and HOW it works...
I modded my dock to accept charge and host at same time but only triggers charge when hdd is connected whilst power applied.
I've got one from ebay. But its very poor quality. Its functionality is OK, but you cannot charge the Tab. External power is used to power the USB devices. It switches between internal Tab 5V and external 5V when applied. It ok with USB hdd that needs power.
o.k. thanks..
Cant help but wonder about the possibility of using it as charging and host at same time by using different resistor than 20k.not sure if you guys seen the thread about host and charging on galaxy s3 (hw mod) but they discovered a different resistance value 40.2k that could make the power part of the usb travel in both directions at the same time allowing this to happen...
im thinking the same could maybe happen for our 7.7 tab.
rEVOLVE said:
Anyone know about a splitter that will take the 30-pin input and let you use one side for the 30-pin power adapter and the other side for 30-pin accessory like USB OTG pigtail?
Click to expand...
Click to collapse
Chdck this out. Haven't tried yet, but this ought to work.
http://www.ebay.com/itm/130707719450
Sent from my GT-P6800 using Tapatalk 2
Manipur said:
Chdck this out. Haven't tried yet, but this ought to work.
http://www.ebay.com/itm/130707719450
Sent from my GT-P6800 using Tapatalk 2
Click to expand...
Click to collapse
Ordered. Will report back once i get it.
ToastyZ71 said:
This is a bit of an old thread, but thought people might like to know that I have found a solution! DealExtreme has a splitter that has 2 OTG connectors and a charging connector....
3-in-1 30 Pin Male to USB Female OTG Hub Cable for Samsung Galaxy Tab - Black + White
Click to expand...
Click to collapse
Ordered this one few days ago but unfortunately it's not in stock and they don't know when they will have it back in stock so, are there some other options?
rEVOLVE said:
Ordered. Will report back once i get it.
Click to expand...
Click to collapse
Hey, did you get it? How is it?
Hey guys,
I just bought a solar USB Hub (with white LEDs as a torch) from Ebay and combined it with the OTG Cable to have a portable USB Hub.(no need for AC adapter except charging the hub from time to time) I had to do a little mod to prevent Evo draining the battery of the hub to charge itself. If you decide to do the same thing, when you cut the OTG cable and original hub cable, there are 4 wires, you only connect black, white and green, leave red disconnected. This way the hub doesn't provide power to the phone (otherwise you can use it only for 2 minutes or so). I then disabled automatic mounting of USB devices (despite unmounting it in terminal properly, unmounting always gave error: unexpected USB device disconnect) and used USB OTG helper v4.0 to mount and unmount. Everything is great now
ozkaya said:
Hey guys,
I just bought a solar USB Hub (with white LEDs as a torch) from Ebay and combined it with the OTG Cable to have a portable USB Hub.(no need for AC adapter except charging the hub from time to time) I had to do a little mod to prevent Evo draining the battery of the hub to charge itself. If you decide to do the same thing, when you cut the OTG cable and original hub cable, there are 4 wires, you only connect black, white and green, leave red disconnected. This way the hub doesn't provide power to the phone (otherwise you can use it only for 2 minutes or so). I then disabled automatic mounting of USB devices (despite unmounting it in terminal properly, unmounting always gave error: unexpected USB device disconnect) and used USB OTG helper v4.0 to mount and unmount. Everything is great now
Click to expand...
Click to collapse
WoW!
How You got Your Evo charging in OTG mode??
I have modified 2-port portable charger Bliss PowerBank u12000 and stock microusb<=>usb cable (NOT otg cable), and when I turn HOST mode on by running
PHP:
echo host > /sys/kernel/debug/msm_otg/mode
my Evo stop charging, but start detecting other USB devices plugged in another port of charger (I have connected same pins inside it and unsoldered all other resistors between them).
And, uhh... where can one buy this said solar powered usb hub? I haven't found anything on google
posedatull said:
And, uhh... where can one buy this said solar powered usb hub? I haven't found anything on google
Click to expand...
Click to collapse
Not the same model, but here's one on eBay. Also available on Amazon.
And here's the one from the OP of this thread. It even has a flashlight. Also available on Amazon or eBay.
ramjet73
S-trace said:
WoW!
How You got Your Evo charging in OTG mode??
I have modified 2-port portable charger Bliss PowerBank u12000 and stock microusb<=>usb cable (NOT otg cable), and when I turn HOST mode on by running
PHP:
echo host > /sys/kernel/debug/msm_otg/mode
my Evo stop charging, but start detecting other USB devices plugged in another port of charger (I have connected same pins inside it and unsoldered all other resistors between them).
Click to expand...
Click to collapse
are you saying that you use a usb charger to support OTG and charge when not used as OTG ?
that u12000 unit would be great if you did what i ask about..
i realize it does not support OTG + charging at the same time..
i have an HP Touchpad that i would like to apply the mods from this thread.
tahnx
I have some HP TP otg mods and a USB charger mod (others too) that you might, be interested in...
[MOD] Self Powered USB OTG on the HP Touchpad! (v2 Full Size) 11-30-12
Also check out: [Tips and Tricks] OTG (USB Host Support) - Requires kernel support
Edit: It looks like you found it.
Here's a similar one http://amzn.com/B0084JVMBU but I don't see a spec for the battery capacity & charge rate (might be 700mah).
mpgrimm2 said:
OK I see what he did with the charger. It uses an adapter (host) cable to go from the main hub port to the PC (mini-USB to full size USB-A).
It looks like he spliced the micro-USB OTG cable (pin 4&5 shorted) to a mini-USB cable, and made a custom OTG Host cable. He mentions he disconnected/broke the +5v wire to prevent it charging the phone due to the small battery in it (understandable). I wouldn't do that myself, but I'd also ideally want a 3000-4000mah Solar Hub to modify for OTG & keeping the phone/tablet charged.
Have a look at my OTG cable schematics in reference post 9 above, particularly cable 1.
Sent from my "Up all night, sleep all day" HP CM9 Touchpad
Click to expand...
Click to collapse
amkaos said:
are you saying that you use a usb charger to support OTG and charge when not used as OTG ?
that u12000 unit would be great if you did what i ask about..
i realize it does not support OTG + charging at the same time..
i have an HP Touchpad that i would like to apply the mods from this thread.
tahnx
Click to expand...
Click to collapse
Yes, I'm using u12000 exactly as You described, but asked here about OTG and charging at same time. Just open u12000 and unsolder 4 resistors between USB port pins and it will become perfect powered portable USB gender changer.
Yes, it looks like that our Evo's doesn't support OTG and charging at same time(
S-trace said:
Yes, I'm using u12000 exactly as You described, but asked here about OTG and charging at same time. Just open u12000 and unsolder 4 resistors between USB port pins and it will become perfect powered portable USB gender changer.
Yes, it looks like that our Evo's doesn't support OTG and charging at same time(
Click to expand...
Click to collapse
Where is the link to this "u12000"? I've clicked all the links in this thread and don't see anything that lists that item/model #.
Also, by removing the resistors (between D+ and D- lines), you've "likely" limited the output the phone will charge at to 500ma, where as shorted together (or small load b/w) it will usually allow the device to charge at it's max allowed rate. Hopefully you are already aware of this.
mpgrimm2 said:
Where is the link to this "u12000"? I've clicked all the links in this thread and don't see anything that lists that item/model #.
Also, by removing the resistors (between D+ and D- lines), you've "likely" limited the output the phone will charge at to 500ma, where as shorted together (or small load b/w) it will usually allow the device to charge at it's max allowed rate. Hopefully you are already aware of this.
Click to expand...
Click to collapse
Bliss Power Bank U12000 - just google it and find internet shop to buy it.
Yes, You are right, removing those resistors limited default charging current to 0.5A, but I'm using latest FastCharge kernel patch and in smart mode it using full 1A to charge, with no side effects. I just tested mine U12000 and found that it can produce 2.25A in short-circuit on USB, it rated as 2A => fully follow its specifications. It can charge stock Evo 3D's battery up to 3.5 times with fully charged U12000 battery.
mpgrimm2 said:
Where is the link to this "u12000"? I've clicked all the links in this thread and don't see anything that lists that item/model #.
Also, by removing the resistors (between D+ and D- lines), you've "likely" limited the output the phone will charge at to 500ma, where as shorted together (or small load b/w) it will usually allow the device to charge at it's max allowed rate. Hopefully you are already aware of this.
Click to expand...
Click to collapse
"Where is the link to this "u12000"?" .. i googled Bliss PowerBank u12000 and found it.. today i couldnt find english page..
i am still unclear if any charger is easily modded to provide OTG data transfer.. if so, would it still charge when not connected to a OTG cable?
amkaos said:
i am still unclear if any charger is easily modded to provide OTG data transfer.. if so, would it still charge when not connected to a OTG cable?
Click to expand...
Click to collapse
Yes, mine Bliss u12000 charging Evo 3D when Evo 3D is not in OTG mode (connected via STOCK cable, NOT via OTG or so). But when I turn on OTG mode on Evo it stop charging but start detecting other USB devices connected to another port of u12000.
I don't know if any charger can be easily modded, but I think if it has 2 USB ports one above another (like =) and NOT side by side (like - -)
- it can be modded (of course if You can disassemble it).
S-trace said:
But when I turn on OTG mode on Evo it stop charging but start detecting other USB devices connected to another port of u12000.
I don't know if any charger can be easily modded, but I think if it has 2 USB ports one above another (like =) and NOT side by side (like - -)
- it can be modded (of course if You can disassemble it).
Click to expand...
Click to collapse
i dont have evo phone so i ask :: do you enable OTG from the phone Or by just using the OTG cable.. or both actions?
also, i tried to find an English site . have you seen one ?
thanx
amkaos said:
i dont have evo phone so i ask :: do you enable OTG from the phone Or by just using the OTG cable.. or both actions?
also, i tried to find an English site . have you seen one ?
thanx
Click to expand...
Click to collapse
I'm enabling it on phone using terminal emulator (look behind in this thread and You will see exactly how).
No, I didn't seen English site, sorry. I'm from Russia.
mpgrimm2 said:
Where is the link to this "u12000"? I've clicked all the links in this thread and don't see anything that lists that item/model #.
Click to expand...
Click to collapse
amkaos said:
"Where is the link to this "u12000"?" .. i googled Bliss PowerBank u12000 and found it.. today i couldnt find english page..
Click to expand...
Click to collapse
Here's the link to the Bliss PowerBank U12000. I translated that page to English in Chrome and the specs are attached, but I don't think Bliss ships outside Russia.
There are many battery based USB chargers available from other sources, including this 12000mAh solar model from usb.brando.com, the same website that has the solar 4-port hub in the OP of this thread. They are Hong Kong based and ship world wide, and their website is available in many languages, including Russian.
If you search for "usb charger" or "usb solar charger' on their site you will find many more models with varying capacities, most of which are probably available on eBay as well.
ramjet73
Some kernels for the Evo 3D on XDA now have On-The-Go (OTG) USB host support built-in so it's very easy to support USB peripherals such as keyboards, mice, flash drives and portable hard drives from your phone regardless of the ROM installed. If you would like more information about OTG, here's a very good thread in the XDA Sensation forum that covers it pretty well.
The commands to mount and unmount USB storage devices manually are covered in that thread, but I've found the easiest way to mount and dismount my flash drive is to use an app called [root]StickMount from Chainfire, the developer of SuperSU. Depending on the ROM installed, it may not be considered compatible and won't show in the Play Store, so I've attached the .apk in case that happens.
I haven't used devices other than flash drives so far on my phone, but other users have indicated that keyboards, mice and other USB devices also work. If you are using OTG to attach any type of USB devices, please share your experiences and any tips you might have. Also, please use this thread for any questions you might have about OTG support and devices, even if you haven't gotten around to trying it yourself yet.
Other XDA threads about OTG related stuff:
Solar powered USB hub (kinda cool)
usb otg cradle
Nitty gritty OTG hardware discussion
Post with diagram of OTG connections
Thanks to mpgrimm2 for suggesting that we share this information from another site (there's actually more over there ).
ramjet73
I want to thank Markmx6 for his guide on another site that was easy for me to follow to make my own OTG cable and Ramjet73 for digging up and posting his links here. Maybe Markmx6 will add his info over here now too since all this works with the Buttered Toast Kernel (bigwillyg).
I got to looking around and wondering with the parts I have if I am setup for OTG and just need to plug everything together without hacking up a power supply which I'd prefer not to do.
Here's what I have on hand:
I ohmed out the " CrazyOnDigital 2 port charger's" data pins:
Port1-pin3 & port2-pin3 = 0.1 ohms (and about 30k to gnd/shld)
Port1-pin2 & port2-pin2 = 0.1 ohms (and about 30k to gnd/shld)
(I also reversed the leads in case I was reading through a diode)
So it looks like the data pins on this aren't shorted together and that it will function as a Powered USB "y" cable/pass through between ports 1 & 2.
Part 2
I realize that my purchased USB OTG cable won't plug in between the charger & my phone so I may use a USB extension Cable and USB A to A adapter that I have (not pictured) or I may just hack a spare USB A to Micro USB (5pin) cable that I have into another OTG Cable.
Q: My understanding is that an OTG cable has the ID pin (pin 4 of the 5pin Micro) tied to Gnd, like Markmx6 did in his original cable; correct? So, that's why the micro USB end gets cut open a bit.
A: Yes.
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My Additional References:
Zoom [DIY] MicroUSB Host Cable
So in a normal micro/mini USB cable, there are 4 wires, 5 pins.
1. Red - V+
2. White - Data -
3. Green - Data +
4. Empty
5. Black - Ground
That micro male to mini female cable above has the 4th (5th?) wire, brown. This is the ID wire. Shorted to ground, it makes the cable a host cable.
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Wikipedia's: USB On-The-Go page
The OTG cable has a micro-A plug on one side, and a micro-B plug on the other (it cannot have two plugs of the same type). OTG adds a fifth pin to the standard USB connector, called the ID-pin; the micro-A plug has the ID pin grounded, while the ID in the micro-B plug is floating. The device that has a micro-A plugged in becomes an OTG A-device, and the one that has micro-B plugged becomes a B-device. The type of the plug inserted is detected by the state of the pin ID .
Three additional ID pin states are defined[4] at the nominal resistance values of 124 kΩ, 68 kΩ, and 36.5 kΩ, with respect to the ground pin. These permit the device to work with a USB Accessory Charger Adapter which allows the OTG device to be attached to both a charger and another device simultaneously.[6]
These three states are used in the cases of:
- A charger and either no device or an A-device that is not asserting VBUS (not providing power) are attached. The OTG device is allowed to charge and initiate SRP but not connect.[6]
- A charger and an A-device that is asserting VBUS (is providing power) are attached. The OTG device is allowed to charge and connect but not initiate SRP.[6]
- A charger and a B-device are attached. The OTG device is allowed to charge and enter host mode.[6]
Click to expand...
Click to collapse
Micro-USB connector pinout
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Part3: SUCCESS! (with Otg Enabled kernel)
I went ahead and modified a spare USB A to Micro B cable for OTG without power. Plugged everything up with my Logitech Wireless USB mouse and it works! Cool as can be! See new pics. (Yellow wire is the Jumper).
Still have a few questions:
Q: Would the "purchased" OTG Cable already have pin 4 & 5 Shorted?
A: YES it should, but one of the cables I bought was defective.
Q: Does your OTG setup from the op charge the phone at the same time (and/or keep it charged)?
A: Yes
Edit: Apparently I broke the +5v wire during reassembling the cable. See next post.
(SEE UPDATED POSTS FARTHER DOWN)
EDIT:
In Relation to my Following Posts, I have patched together the following cable schematics as a reference to the cables I have either made or purchased.
If you have the ability & willingness to find out what the ID pin resistance is in your "Accessory" device as mentioned below please let me know. I am trying to correlate the info from the Wikipedia/USB OTG reference to all the available ID pin states.
Mpgrimm2; I have a small update from some of my testing regarding the USB OTG 4 ID pin states (pin 4 to pin 5 "gnd" ).
Ininity (Open) = Standard USB data/charge
0 Ω (shorted) = USB OTG host
36.5K Ω = desktop cradle/dock
(my seidio actually has a 47k Ω resistor said:
Anyone want to open their car dock and check the resistor?
Anyone want to open their MHL adapter & check the resistor on that too?[/COLOR]
Wikipedia's: USB On-The-Go page
Click to expand...
Click to collapse
Here's what I've found out or verified:
- I'm still not sure about the 3 different USB OTG ID modes that were mentioned. In the test rig (pictured) for different values of resistance between pin 4 (ID) and pin 5 (gnd):
0 ohm (Short) = USB OTG host
36.5k ohm (47k in use) = Dock Mode
68K ohm (74k in use) = Dock Mode
124k Ohm (127k in use) = No discernible effect
I also determined that my first homemade USB OTG cable wouldn't allow the phone to charge because of a broken +5v wire during reassembly (new one works correctly, but so far I preferred the simplicity of the original setup & charger over the new cable I made, but time will tell.
Here's the Ebay link to the OTG cable RamJet73 recommended (same as the last one I made b/c I didn't want to wait) so that I can keep it linked in one place.
Here are the pictures of the 2nd cable that I made that is "very similar" to the one Ramjet73 mentioned at eBay but 2ft longer (See Schematic #4 in later post).
Keep in mind that the OTG function will be disabled if an OTG cable is plugged into a USB charger that has the data pins shorted internally (AC charging), but this doesn't appear to happen with a powered hub (isolated)
Markmx6's "Homemade Powered OTG Cable" Part 1
I got permission from Markmx6 to repost this here:
Markmx6; said:
First off, I am not responsible for you screwing up your phone, shorting your house out, frying your SD card, burning down your home, or anything else that may or may not occur from you building this...
Tools you will need: Razor blade, Soldering iron, Solder, Super glue.
Optional tools: Dremel with cut-off wheel.
I started with components I imagine you will all have, since they came with the phone. The HTC charging cable and outlet adapter.
First, cut around the base of the outlet adapter. This is around 3/16" thick, and the cut is better off to be made on the "shiny" plastic than the "dull" portion. I used a Dremel, but any type of blade will do, it just may take more time.
Make a cut along the white line on the board (Shown in red here) Otherwise this will not work. On typical chargers they short out the Data+ and the Data- connections (mpg2 edit: it forces "AC Charging" mode). Not sure why... Digging a razor blade across this several times should do the trick, but if you want to make sure with a continuity tester that will always give piece of mind.
Now you need to cut your cable, I recommend leaving around 2" or more from the standard usb side. (A little of this wire will come in handy for later in this project)
Cut and then strip your wires, there will be a braided shielding wire just under the insulation. Then it will be helpful to "Tin" the ends of your wires.
The shielding can be completely removed, or you can ground it out, but I haven't found this to be needed.
You will now need to solder the wires to the circuit board. This will obviously need to be in the correct order.
From the top will be:
RED = 5V+
WHITE = Data +
GREEN = Data -
BLACK = 5V-
Now you can re-assemble the Outlet adapter if you choose.
Now you need to cut up the other (phone) end of your cable to enable the OTG function.
Post 2 will outline this.
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Click to collapse
Markmx6's "Homemade Powered OTG Cable" Part 2
Markmx6; said:
Carefully cut down the sides of the connector, if you can do this in one clean cut it will be helpful when you re-attach then after your modifications.
Carefully cut away the plastic, and what looks like hot glue. You need to expose the side that has a blank terminal. and the one on the other side that has a black wire.
Pins 4 and 5 need to be attached, so a small piece of wire (from the leftover ends of the cable comes in handy) works really well.
It doesn't really show up in the pictures though
Now re-glue the pieces from the end of the cable back onto the connector
That is all.
I am using 3.2.8otg for a kernel and negalite2.9 and otg helper and everything works as it should.
http://forum.xda-developers.com/showthread.php?t=1588979
For usb storage you need to have all of the cables hooked up before you insert the SD card.
Click to expand...
Click to collapse
NOTE: Bigwillig's [Kernel] ButteredToasT ICS RLS 04 | Linux 3.0.46 | linaro 4.7 -o3 | otg | HTC beats also supports OTG with any rom that will boot the kernel.
Sent from my "Up all night, Sleep all day" EVO3D!
Ebay/Applecable Purchased OTG Cable & USB Hub
I just verified that if you get the Micro USB Host OTG Cable With USB power ($6 from AppleCable on Ebay) that Ramjet73 mentioned (or this one), it will work with any standard USB charger (ie the 1 Amp HTC or 2 Amp HP Touchpad Charger) because the USB Power Connector is Isolated. I also picked up Applecable's USB 2.0 3 Port Hub with data Sync Charger cable for $7
(I may try to modify it to be a USB OTG powered hub with this OTG Adapter and this USB to 3.5mm/1.3mm Adapter to power the hub directly from "ANY" USB charger.
EDIT: It works fine, but modified it anyway).
Here's some updated AppleCable Ebay Store links (4-18-14):
Micro USB Host OTG Cable With USB power
USB 2.0 3 Port Hub with data Sync Charger cable (not OTG, but a cheap hub that works. can be modified for OTG)
Micro USB Host OTG Cable w/micro USB power
Left Angled Micro USB Host OTG Cable w/USB power
Right Angled Micro USB Host OTG Cable w/USB power
^^^
been looking for something like this!! post back on your progress
mpgrimm2 said:
I just verified that if you get the Micro USB Host OTG Cable With USB power ($6 from AppleCable on Ebay) that Ramjet73 mentioned (or this one), it will work with any standard USB charger (ie the 1 Amp HTC or 2 Amp HP Touchpad Charger) because the USB Power Connector is Isolated. I also picked up Applecable's USB 2.0 3 Port Hub with data Sync Charger cable for $7 (I may try to modify it to be a USB OTG powered hub with this).
Click to expand...
Click to collapse
I just found out that the version of the OTG cable with the female microUSB connector doesn't charge the phone when power is applied to that connector. The eBay listing at your link above doesn't say one way or the other, but this link was posted on another site and that listing specifically says it doesn't. I'm not sure why that is, but it looks like the same brand (Chen Yang) in both listings.
The version with the male USB A connector for power can definitely charge the phone when in use. I've tested that myself.
ramjet73
Now that I've made a few on my own and bought the one you recommended, I can say it likely has to do with the way that it's wired up. I would bet that the Applecable one with the M & F microUSB allows charging.
Note: I also updated my previous post with a new USB to 3.5mm adapter for the hub. I ordered both adapters (so I don't have to cut/solder mods to the hub) and will report back once I get it. (also picked up a 2nd 3d for my son's b-day coming up so I don't waste an upgrade just yet).
Edited
I just don't get it... Found many usb hubs with internal rechargeable batteries, but all are old posts, not available for sell anymore . Why is it so complicated for Evo 3D to connect usb to it? I really want to connect my Razer Banshees to it, but all this running around to find a usb hub with internal battery is killing me, and having one that works on charger is ilogical, from my point of view. If i want to do this, I want it to be portable, otherwise I'd just connect it to my pc/laptop. I connected them to a Galaxy S3 and they worked instantly. I use Coolexe's ROM and Kernel (v4.0), and it says that it has usb support and usb headset support
posedatull said:
I just don't get it... Found many usb hubs with internal rechargeable batteries, but all are old posts, not available for sell anymore . Why is it so complicated for Evo 3D to connect usb to it? I really want to connect my Razer Banshees to it, but all this running around to find a usb hub with internal battery is killing me, and having one that works on charger is ilogical, from my point of view. If i want to do this, I want it to be portable, otherwise I'd just connect it to my pc/laptop. I connected them to a Galaxy S3 and they worked instantly. I use Coolexe's ROM and Kernel (v4.0), and it says that it has usb support and usb headset support
Click to expand...
Click to collapse
Unlike Samsung, HTC hasn't officially supported OTG so we are lucky to have some ROM's and kernels that do support it. Even the utilities like stickmount don't download from the Play Store because the Evo 3D is not considered a compatible device.
USB mice and keyboards can work without external power, but many other devices need power and would drain the phone battery very quickly even if they could use it. I have no experience with USB headphones on a phone, but it would make more sense to me to have batteries in the headphones and not depend on the phone for power. Another possibilty may be to use an external battery like this one connected to an OTG adapter that includes a connector for external power, but I haven't test that.
I use rechargeable stereo bluetooth headphones so I don't have to mess with cables at all, but if you prefer the USB headphones the options may be more limited with the Evo 3D than the SGS3.
ramjet73
Between the items Ramjet73 and I have mentioned in previous posts (edited below), you should be able to piece together the functionality you are looking for, but still not ideal as far as portability. Markmx6 has mentioned making his own "D" battery powered usb hub (I think) that he may post here sometime. Hope this helps.
mpgrimm2 said:
I also picked up
this USB 2.0 3 Port Hub with data Sync Charger cable for $7
this OTG Adapter
this USB to 3.5mm/1.3mm Adapter to power the hub directly from a USB port/charger).
Click to expand...
Click to collapse
ramjet73 said:
Another possibilty may be to use an external battery
like Rechargeable USB Universal Battery connected to an OTG adapter that includes a connector for external power, but I haven't tested that.
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Click to collapse
Good find Ramjet73! Got me thinking about options again, just waiting on my parts to get here. Mind if I paste this into the other sites thread?
Saw this app posted in the Buttered Toast thread and may give it a try for NTFS support:
mnomaanw said:
You can mount NTFS drives with this App ----> https://play.google.com/store/apps/details?id=com.paragon.mounter&hl=en
I think it can mount exFAT also.
Click to expand...
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posedatull said:
I just don't get it... Found many usb hubs with internal rechargeable batteries, but all are old posts, not available for sell anymore . Why is it so complicated for Evo 3D to connect usb to it? I really want to connect my Razer Banshees to it, but all this running around to find a usb hub with internal battery is killing me, and having one that works on charger is ilogical, from my point of view. If i want to do this, I want it to be portable, otherwise I'd just connect it to my pc/laptop. I connected them to a Galaxy S3 and they worked instantly. I use Coolexe's ROM and Kernel (v4.0), and it says that it has usb support and usb headset support
Click to expand...
Click to collapse
I built a 4 port charger using four "D" batteries for a trip I took to Disney world (five kids on a six hour flight.... required someway to recharge Nooks, cell phones, and etc)
To break it down simply I used a four battery holder. (Apparently I don't have enough posts to post links, pull up radioshacks website and search for "D" battery holder)
You don't need "D" batteries as these are bulky, I used them because size wasn't really a factor. "AA" or "AAA" batteries should be fine. Remember Alkaline batteries provide 1.5 volts each NiCad (Older rechargeable) 1.2 volts There are newer voltages to my knowledge...
I used four batteries because it produces 6 volts in series. MAY POSSIBLY DAMAGE YOUR PHONE
Ideally you would provide 5 volts which is what USB provides, I find 6 volts worked fine for me.
For my charger I shorted the DATA +/- terminals together to fool the phone into believing it was using AC power for a faster charge.
All you really need to do to continue to use the hub as a Data transfer device would be to solder the red and black wires to their respective terminals on the hub, it shouldn't matter which port you use as they should all be linked, other hubs may vary.
You may also be able to just wire a female USB port onto the battery holder and use a hub plugged into that...
My CrazyOnDigital 2 port charger doesn't have the data pins shorted (D+ and D-) like the stock HTC unit. This causes any "Android" phone to charge at the lower 500ma Max "Charging USB" rate vs "AC Charging" (explains my slow charging when travelling), but a bonus is that it allows me to pass data b/w the 2 ports like a simple hub.
- If the D+ and D- pins are shorted when an OTG USB cable is plugged in, the phone will go into "AC Charging" mode, but not allow OTG devices to work, but if the phone is still connected and the data pins opened back up, you retain "AC Charging" mode and have USB OTG functions.
(I'm thinking that a simple on/off switch installed across the data pins of my charger will give me a dual mode charger).
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AC CHARGING / USB CHARGING (Data Pass Through) MOD 12-1-12
- I got tired of having a 2 port 2 Amp charger that only allowed 500ma "USB Charging" with Android & OTG. See pix:
mpgrimm2 said:
I just verified that if you get the Micro USB Host OTG Cable With USB power ($6 from AppleCable on Ebay) that Ramjet73 mentioned (or this one), it will work with any standard USB charger (ie the 1 Amp HTC or 2 Amp HP Touchpad Charger) because the USB Power Connector is Isolated. I also picked up Applecable's USB 2.0 3 Port Hub with data Sync Charger cable for $7
(I may try to modify it to be a USB OTG powered hub with this OTG Adapter and this USB to 3.5mm/1.3mm Adapter to power the hub directly from "ANY" USB charger).
Click to expand...
Click to collapse
And here is my new OTG setup with the modified charger (no need to modify the charger with this) and modified hub:
Also works well with [MOD] Self Powered USB OTG on the HP Touchpad! (v2 Full Size) 11-30-12
Just out of curiousity, will a sixaxis controller be supported by otg? Could anybody confirm this for me.
Jsparta26 said:
Just out of curiousity, will a sixaxis controller be supported by otg? Could anybody confirm this for me.
Click to expand...
Click to collapse
I saw someone taking about it in the HP Touchpad CM9 thread, I will see if I can find the post & report back.
update: post was here
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Separately, I saw this (couldn't find the u12000 solar hub mentioned previously)
Opteka BP-SC4000 Ultra Thin Solar Powered High Capacity (4000mAh) Backup Battery and Charger
I know some have mentioned an interest in an all in one OTG enabled solar powered charger with battery backup. Sounds easy enough with the correct parts.
Sent from my "Up all night, sleep all day" HP CM9 Touchpad