yashsingh1/xdaforums huggingface dataset:
[Galaxy Tab General] WarlockM:
Hi. I've solved the problem of using other chargers with GT.

Like Apple, Samsung used a little trick with their chargers.

To charge your GT with any usb charger you have to make a little adapter.

Usb pinout:

gnd d- d+ 5v

To work you must short d+ and d-.

From 5v use a 33k resistor to d+/d-.

From gnd use a 10k resistor to d+/d-.

If you have multimeter you should obtain ~4v between 5v and d+/d-; and ~1v between gnd and d+/d-.

I tested it and it's working.
[Galaxy Tab General] adolfotregosa:
Hi, it's not a trick but a standard. You only need to short d+ with d-, the resistors are not needed. Just be sure that the charger outputs closest to 5v possible, around 5.2~3 usually work for everything. About 5.6v and it start not to work on some devices, like apple..
[Galaxy Tab General] WarlockM:
Maybe, I have to test that :)

I know it's not a trick, I should wrote "trick".

For example GT adapter outputs 5.31v.

Apple adapter worked with 1 22k resistor between d- d+.
[Galaxy Tab General] MizGarfield:
How can you do that? You need an extra device adapter? Please explain.
[Galaxy Tab General] WarlockM:
I've tested with d-/d+ shorted and it's not working.

@MizGarfield if u have 1 usb extension cable u can cut it on half.

Tie together white and green wires.

Tie black wires and conected to that 1 end of 10kohm resistor, the other end tie it to green/white wire.

Same to red wires but use 33kohm resistor.

See att. Sry for drawing.
[Galaxy Tab General] SiL3nTKiLL:
bookmarking this for later use :)
[Galaxy Tab General] adolfotregosa:
You don't need that for modern devices has i told you. It did not work because you did it wrong. I have all my usb chargers working the new way, you even have wikipedia talking about it. You have to cut the data + and - on the power supply from the female usb port and short only the female d+ and d-. Trust me it works and it is alot simpler.

Edit : from wikipedia "The Dedicated Charging Port shorts the D+ and D- pins with a resistance of at most 200 Ω. The short disables data transfer, but allows devices to detect the Dedicated Charging Port and allows very simple, high current chargers to be manufactured. The increased current (faster, 9 W charging) will occur once both the host/hub and devices support the new charging specification."

""As of June 14, 2007, all new mobile phones applying for a license in China are required to use the USB port as a power port.[35][36] This was the first standard to use the convention of shorting D+ and D-.[37]""

http://apple.slashdot.org/story/10/08/03/1743240/Hardware-Hackers-Reveal-Apples-Charger-Secrets

""We all love to call out Apple when they design deliberate incompatibility into their devices, but there is a perfectly valid technical reason for what Apple is doing here, and, in fact, they are following a USB specification (which LadyAda unfortunaterly didn't even test).

Without data communications or when suspended, devices may legally draw no more than 2.5mA from a host, which is useless for charging. In fact, even if you're generous and pretend they're connected, devices are not allowed to draw more than 100mA without negotiating for a higher current, which requires actually talking to the host, and 100mA is still too little to charge properly. 500mA is the maximum allowed by the USB spec, but devices must negotiate it (there may be too many devices on the bus for negotiation to succeed).

Before there was a spec for "dumb" USB chargers, Apple used the resistors as a sentinel to avoid drawing too much current from undersized chargers in order to avoid damaging the host. This is a hack, but it works, and honestly, we're smart enough to figure out a couple resistors on the data lines. It's not like they're using crypto auth on the charger. They have a perfectly valid reason to do this. Devices which charge from "dumb" chargers aren't following the spec, though this is a common industry practice.

As it turns out, the USB-IF came up with a USB Battery Charging spec [usb.org]. The spec is long and boring, but it boils down to: short together the data lines (no resistors required) and you indicate that you're a dumb charger that can supply anywhere from 0.5A to 1.5A.

Guess what happens when you short the data lines of an iPhone 3G and supply 5V [marcansoft.com]. Did Apple just follow a standard? Incredible!

(Yes, I'm not following the USB spec there by in turn using a USB cable to supply the 5V and not negotiating over its data lines. I didn't feel like grabbing a dedicated 5V PSU for the shot, so sue me.)"""

http://marcansoft.com/transf/iphonechg.jpg

ok ??? :D no need for resistors, only 5.3V MAX and d+ and d- shorted
[Galaxy Tab General] geogetski666:
Thnx for the tip gonna try this later on my sanyo eneloop power booster tried it yesterday without this mod and it doesn't charge :) so gonna look for a AF to AF converter and modify it to gound the D+ and D- :)
[Galaxy Tab General] WarlockM:
@adolfotregosa

I tried again shorting d-d+, with iphone it works but with GT it's not working.

I use BatteryWatch and it is saying Not Charging. It's detecting the connection like usb port but is not. I use some device build by myself with 1 amp capabilities. D- and D+ r free of any connection and i can do with them what i want.

I dont say you r wrong but it's not working with GT. :)
[Galaxy Tab General] adolfotregosa:
but smt is wrong on your custom setup, voltage ??

EDIT: i just measure the original charger and it has no resistance between the data and power pins.

I think i know what could be wrong, when you plug in the Tab and it says not charging, how many volts have you got at that time ?

The original charger is very good because when it not charging the tab it has 5.3x volts but when you plug it in it lowers to 4.8x V Max and that is very good ! most chargers tend to lower much more (bad quality or just not powerful enough) and that is what causes the not charging messages on the tab or other devices.

Well i rest my case on this.
[Galaxy Tab General] WarlockM:
My device with no load it have 5.21v and with load 5.03v so it's not from him and i have another supply 5v/12 amp and it's doing the same (not charging, only with data shorted).

When u r trying to measure the original ps u can read ~7k between gnd and data but from 5v to data u cant because it have some capacitors.

Maybe samsund did something else, i have to try, maybe data pins drawing some current (mA) and that's why it's not working with only shorting them.

For the moment it's the only (working) solution i've found and i'm happy with it :).

P.S. If i'm not finding anything else the last resort will be to open the original ps :)
[Galaxy Tab General] rick75204:
USB Charger

This is what worked for me.

Items Needed:

USB Extension Cable

33k-Ohm Resistor (Shack Part No. 271-1129)

10k-Ohm Resistor (Shack Part No. 271-006)

Steps:

1. Cut USB Extension Cable in half, lets name the 2 halves, the half you will plug into the power suppy will be called "Cable A" and the half that you plug into the Galaxy Tab Data Cable will be called "Cable B"

2. On 'Cable A" strip outer plastic to expose all wires within, eliminate Green and White on this cable only as it will not be needed, leaving you with only the Red and the Black Cables

3. On "Cable B" strip outer plastic to expose all wires within, this should leave you exposing all 4 wires

4. On "Cable B" strip both the Green and White wires and join thes 2 wires with the 2 resistor ends (you should be using the resistor ends that have the red band with these wires), these can be joined by either soldering or just twisting together.

5. Strip Red wire from both cables and join together with the 33k-Ohm Resister (this will be the larger of the 2 resistors and should also be the end with the Gold Band) and as well join these together with solder or just twisting together.

6. Repeat the above process with the Black wires and 10K-Ohm Resistor.

7. No finally use Electrical Tape or Shrink Tubing to cover all your work.

This worked using it on a Champtek 5v 2.1a USB Car Charger and Home Charger. Also worked with iPhone charger. Also works with Original Galaxy Tab.

Hope this helps out.
[Galaxy Tab General] wnpaul:
May I just ask some clarifying questions?

Does it matter WHICH resistor you join to which of these two wires?

So that you have effectively bridged the red wire with 30K-Ohms to one of either green or white running to the TAB?

And bridged the black wire with 10K-Ohms to the other of either green or white running to the TAB?

Would this be an accurate picture, with the 33K Ohm Resistor on the left, and the 10K Ohm Resistor on the right?
[Galaxy Tab General] kupuguy:
I think the intention was that you short the green and white wires together: so you are connecting both wires to both resistors.

That way the two data lines are both held at a fixed voltage of about 1.2V
[Galaxy Tab General] wnpaul:
Thanks, that clarified it.
[Galaxy Tab General] paulshields:
I noticed today that if I connect my Tab to my keyboard (standard Apple USB KB with keypad, connected to a circa 2006 iMac), the device started charging according to battery stats. When it was plugged in it was at 48% and it ended up at around 60% after a few hours. Am I being deceived or something? I was under the impression that it would only charge if connected to the mains charger. Well I guess I'll see how long it runs now it's off the leash and see if it lasts till the morning (left my charging cable at work - D'oh!).
[Galaxy Tab General] AlexVallat:
No, it definitely does charge even when it says it isn't - just slowly. I've got a 2A non-official USB charger that charges it up pretty quick, but still says it isn't charging. If the screen is off, it will even charge off one of those tiny Kindle chargers that must be delivering less than 500mA, but *really* slowly.
[Galaxy Tab General] eiem:
Clarify

Sorry guys, only a clarification.

As far as i understood:

the GT DOES charge with *any* charger (or connection to PC);

if you use the original charger (2Amp), it charges showing the charging-icon;

if you use a non-original charger, it charges in any case but NOT showing the charging-icon and depending on the charger power (even 1Amp charges, or 500mAmp, *VERY-REALLY* slowly);

if you use a non-original charger with the two resistors (33k + 10k) it charges showing the icon (even with a 1Amp).

Can anybody confirm if i understood well?

Thanks!!
[Galaxy Tab General] sedde:
Thats it for now.
[Galaxy Tab General] Zeron.Wong:
It seems that the Tab could recognize the status of the usb connection by measuring the usb data rx/tx wire level. If it is not shorted, the "pluged in but not in charging" status will appear, as the mismatch voltage of the usb connection is made.
[Galaxy Tab General] wayijie:
WarlockM,thank you very much,I already made a USB ware for my tab and it's working
[Galaxy Tab General] EyeTech:
I too had been struggling with charging with other sources until I built an adaptor as described above. I found the resistors were necessary for me. 2 pics attached.
[Galaxy Tab General] ovone:
Can I buy that adaptor somewhere ? Ebay e.g. ?
[Galaxy Tab General] agentdr8:
I don't think anyone mass-produces those. I just made one last night from stuff I found at Frys. $4 for a usb extension cable and ~$2 for resistors.
[Galaxy Tab General] shoe3rd:
ipad charger compatibility?

I was just wondering if anyone tried an AC/USB ipad charger with the proper cable to charge the Galaxy Tab.

If the products that are sold on dealextreme or ebay charge properly an ipad, and if the same usb trick is necessary to charge the ipad and the gtab, then it should charge the gtab properly.

Am I wrong?
[Galaxy Tab General] annafil:
iPad charger doesn't work, unfortunately.

But I picked up a 2000mA usb universal charger at a local gadget shop, and a third party Tab cable, and even though the icon doesn't indicate charge, the battery level goes up instead of down, albeit slowly so I'm happy for now :)
[Galaxy Tab General] cameronm:
Ive read everywhere that you cant charge the tab via usb but mine does?

Bought last week... Im a bit confused
[Galaxy Tab General] agentdr8:
It charges via USB, but slowly. The OEM 2A charger has different voltages on the data lines that tell the tab to initiate a fast charge at a higher current draw. This is similar to how the iPad chargers work, and why building the usb adapter in this thread helps when charging via non OEM chargers (including USB ports).
[Galaxy Tab General] doloop:
Reminds me about hd2 kernel developpement discussion: like on our tabs, i think the kernel was responsible for choosing charging rate, because some kernels with bugs were keeping slow charge mode whatever the supply was.

On non buggy kernels, it seems the trigger was connection of data lines: a computer does connect data lines -> slow charge, a wall charger does not -> fast charge.

As soon as will have custom kernels for our tabs, we'll be able to change the charge mode that the tab choose. Some computer have powerfull usb power line. However some low quality usb car power adapter could get destroyed if our tab use fast charge mode for too long.
[Galaxy Tab General] Coolsaber57:
Ok, I'm a little confused as to how this is supposed to go when soldering the resistors.

Can someone clarify which version is correct? I'm leaning toward the one on the right, but I want to be sure.
[Galaxy Tab General] agentdr8:
You're right. It's the one on the right.
[Galaxy Tab General] Coolsaber57:
Awesome, thank you sir :)
[Galaxy Tab General] Coolsaber57:
It works!

Following the instructions (and the diagram I made) I was finally able to get the tab to charge via USB.

I had an old crappy 1ft extension cable lying around, so my first 2 attempts used that. They failed due to the wires being too small to easily strip and too weak to hold together while soldering.

I went to the store and grabbed a thicker looking cable and tried 1 more time and voila! Charging.

One piece of advice to anyone doing this: use a razorblade to strip the wires vs. a wire stripper. They are really small and the coating is very much molded around the copper wire, making a wire stripper difficult to use without ripping half of the wires out.

Thanks again to everyone in this thread!
[Galaxy Tab General] ajayendra:
Wow this is so cool!

Tried this and now the GT is charging and charging FAST, even with 1000mA charger. I made one USB juction what has been in discussion which worked great and then I opened up a $0.69 usb charger (1000mA), soldered the resistors right on the board and voila!...

Thanks a lot!
[Galaxy Tab General] wirelezzz:
nice

im going to make an adapter for mine today , i have a nice huge electronic deparment beside me where i can buy lots of this components. ill make a couple to have laying arround lol.
[Galaxy Tab General] wirelezzz:
got my parts and ready to build some adapters

time to go to work , ill make a few of these to have laying arround
[Galaxy Tab General] mingkee:
I was led to this thread about USB charging solution. Now I have a object. You need:

a PCB (generic from ratshak or you can print and etch)

an A-type USB female jack

a miniUSB jack (SMT type is OK)

a 10k ohm resistor

a 33k ohm resistor

When assembling, make sure you're clear pos and neg and solder everthing on the PCB. Additional solder may be required on miniUSB jack to reinforce it.

edit:

I made a draft one.
[Galaxy Tab General] everunman:
confirming those who dont want to make their own charge adapter can buy this one on ebay, it works great, can charge from usb or other usb portable chargers

edit cant post a link as im not at 8 posts but search ebay for

Adapter für Samsung Galaxy Tab - USB auf USB Adapter
[Galaxy Tab General] galexandr:
Would you be willing to sell one to me?

Please?
[Galaxy Tab General] knightnz:
Wierd, I can plug my SGT into pretty much anything (laptop, USB hub) and it shows the charging icon.
[Galaxy Tab General] galexandr:
what did you do to make it charge? im having trouble charging from my pc and mac, only charges well from the wall!
[Galaxy Tab General] brendodendo:
So my tab (GT-P1000, 2.2, P1000XXJMA, 2.6.32.9root@SEI-28 #1, FROYO.XXJME) will charge using any charger or usb, but I get the charging "lightning bolt" with a small red x.

This does not matter if I use a Motorola charger w/ 5.7V,850mA, a Blackberry w/ 5.0V, 500mA, another Blackberry w/ 5V,750mA or an LG charger w/5.1V,700mA.

So today, I ran around to the local electronics store and to the "city" to radio shack and picked up some 1/4 watt resistors. I had to buy the big pack, as radio shack here in the sticks thinks we don't need 33ohm resistors. So I ripped apart an old PC for the female end and a usb cable for male. Now I have the rest of the parts. I found the correct resistors (10ohm = black, brown, brown, gold) and (33ohm = orange, orange, black, gold) in the package.

I then soldered wires strait across between pins 1 (+) and Pin 4 (-). Then soldered the 33ohm resistor to pin 1 and the 10 ohm resistor to pin 4 on the male jack (to charger side). Then I soldered a small horseshoe to pins 2 and 3 on the female jack (tab side). Lastly, I soldered the resistor ends to the horseshoe.

I tested the voltage. Pin 1(+) and 4 (-) read 4.88V. Pin 2 and 4 read 1.2V and Pins 3 and 4 read 1.2V. So I superglue the unit together and shrink tube it.

Now when I plug in a charger to the dongle and the tab, the tab says "connected to USB". Did I mess something up, or is this correct.

I wish I had the OG charger, but that is probably somewhere in Argentina right now.
[Galaxy Tab General] cybermaus:
Found this thread while digging for info, and though a warning was in order:

That's 10k and 33k ohm, not 10 and 33. (so black brown orange gold & orange orange orange gold)

If you use the non-kilo versions, it may work, but you'll burn an extra 116mA (or 0.6Watt) in the resistors, so the resistors themselves will get hot.

Edit: And while on the subject, it seems that Apple want 2V on both D-/D+ for limited 500mA charging, but 2.8V on D+ for 1000mA or higher charging. So the values would be GND - 22k - D- - 10k - D+ - 22k - 5V for Apple.
[Galaxy Tab General] nev310:
I have noticed that sometimes my tab charges on my netbook on the special usb port
[Galaxy Tab General] texasreb:
I just a gobatt 2 charger. It comes with a usb adapter that charges the tab. Also I ordered a usb adapter from amazon in england.
[Galaxy Tab General] nev310:
It might show the icon but does it show its charging?
[Galaxy Tab General] foxmeister:
Previously, I was running MoDaCo on my Tab, and whenever I connected the Tab to my PC via USB, I'd get the not charging symbol (though it did trickle charge).

I didn't think about it until now, but since I've moved to Overcome with the circle/%age battery indicator, it does now show as charging on the batter charger, though in the phone status menu it shows "Not Charging", so I guess it is just trickle charging as usual.

Regards,

Dave
[Galaxy Tab General] sys73r:
My sgt gets charged when plugged to the mac, it is slow but works.
[Galaxy Tab General] 4exess:
Worked for me just shortin D+ D- on GT P1000XXJIE XWJJ3

Tested with iphone travel charger, pc, 0.5 , 1 and 1.5 amps car chargers

works flawlessly
[Galaxy Tab General] deadsimple:
Thanks for the information guys.

I can confirm on my SGT just shorting the data lines doesn't work, but placing them at about 1.3V potential (with 12k + 33k resistors) causes the device to charge properly.

More information:

With the device at about 60% charge, charging off a 12V/2.2Ah sealed lead-acid battery with 2.1A cigarette-lighter adapter and resistor-mod: charging current settled at 500mA (@ 5V).

Swapping the SLA battery over for the stock 2A charger and stock cable (no resistors/adapters): charging current settled at 600mA (@ ~5V).

So it seems like it should charge sufficiently on even 1A adapters - unless someone can confirm that the charging current is higher at a different device charge (example: fully depleted SGT battery).

Just confirmed the stock charger provides 1.25V volts on both white and green data lines. Compared to say the iPhone 1A charger that provides ~2.7V on white and 2.0V on green for a high-current charge on their devices.

Looks like a multi-device adapter with a data voltage-selection switch is in order ...
[Galaxy Tab General] 3Flight:
Made myself an adapter a few minutes ago and it doesn't work. =(((

Used 33kOhm(turned to be 32.7kOhm) and 10kOhm as mentioned in the topic. My USB charger gives 5.03V without load, and when I use "adapter" I have 3.85V on 1-(2+3) and 1.18V on (2+3)-4 - ratio is 3.263/1.

Stock USB charger has 5.37V without load, and gives 4.12V and 1.25V respectively - ratio is 3.296/1.

As you can see, ratio difference between my adapter and stock charger is about 1%.

And the question is - WTF did I do wrong? Or is 5.03V without load not enough?

*Doesn't work means I get a "USB connection" and a "Not charging" status. I guess it still charges, the slow way that is.
[Galaxy Tab General] 1jz68u:
If you turn the tab off it will charge using any usb charger
[Galaxy Tab General] vince_junior:
have you tried it?
[Galaxy Tab General] mtmello:
My sgt reach only 99% of charge even after a lot of hours in 99 it cant reach 100%.

I used apple (iphone) usb charger w/o sucess...

An yone can help me? Any suggestion?

Tks
[Galaxy Tab General] texasreb:
Just get the galaxy tab usb adapter from amazon uk and you can cbarge from any charger.
[Galaxy Tab General] Ricey:
Bought a few adapters on ebay. Will post back once I receive them.

http://cgi.ebay.com/USB-car-wall-ch...ccessories&hash=item2c5c07736b#ht_3085wt_1163
[Galaxy Tab General] byt3b0mb:
i used the diagram on page 5 (the one on the right) and it works fine. tab shows chariging (AC) with the adaptor.
[Galaxy Tab General] hnljay:
I bought one of these for a NookColor and it does work with my SGT Wifi also.

Have the Scosche IPDBAT2 Portable Back Up Battery which comes with an adapter - also works well with SGT, but only with the adaper.
[Galaxy Tab General] leapinlar:
I bought several of these adapters and they worked perfectly with my Tab and every one of my usb chargers (car and home of all capacities). They are marked "Galaxy Tab" and "made in Taiwan." $6.50 each and free shipping.
[Galaxy Tab General] djEthen:
LOL :D:eek::D
[Galaxy Tab General] ResonanceZero:
If you want a converter combined with an ultraslim 12v-to-usb plug, I can confirm that the one here works:

http://www.amazon.com/Satechi-ST-2412-Converter-BlackBerry-Playbook/dp/B004X71HXU
[Galaxy Tab General] FabioMC:
It really works!!!!!!!!!!!!!!!
[Galaxy Tab General] shinakpas:
It really work, my tab charging with two rezistor from any USB port like you said WarlockM! Thank you very much guys!
[Galaxy Tab General] sweets11:
Is there any app that can show the charge rate?

I know the vibrant has a pretty simple one that reads a kernel batt_chg_current value (something like that) and returns the mA.

I think I have it working but I wanted to check that my 2A charger is also outputing the maximum current (as "rated").
[Galaxy Tab General] AZImmortal:
Can anyone comment on whether this charging adapter can be safely used with other devices to enable high current charging? I already have a USB extension cable that I made with the data pins shorted on the device end for use with my phone, and I was wondering if I can keep using it with my phone (or any other device) once I add the resistors.

Battery Monitor Widget can do this, but it doesn't work with all devices and I still have yet to play with my new Tab so I can't confirm that it works specifically with the Tab, and even if it does work, I've been having problems in the last few weeks with it grossly misreporting the charge/discharge rate on my Nook Color (rates in the thousands of amps). It used to work just fine though, so maybe you'll have better luck on your Tab.
[Galaxy Tab General] AZImmortal:
Anyone? I'd rather not fry my other devices, heh.
[Galaxy Tab General] gobiasinc:
Thanks very much for this.
[Galaxy Tab General] khadar:
thnx for the post...

its great i was looking for a car charger....

better if it can charge from any 5v outlet