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Usb charge

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galexandr

Senior Member
Oct 28, 2009
252
22
what did you do to make it charge? im having trouble charging from my pc and mac, only charges well from the wall!
 

brendodendo

Member
Jun 22, 2010
18
1
So my tab (GT-P1000, 2.2, P1000XXJMA, [email protected] #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.
 

cybermaus

Senior Member
Dec 6, 2008
1,233
478
Earth
www.campingtiveden.se
...I found the correct resistors (10ohm = black, brown, brown, gold) and (33ohm = orange, orange, black, gold) in the package...

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.
 
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nev310

Senior Member
Jun 30, 2008
637
24
Memphis, TN
I have noticed that sometimes my tab charges on my netbook on the special usb port

Sent from my SPH-P100 using XDA Premium App
 

texasreb

Senior Member
Nov 26, 2010
56
0
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.
 

foxmeister

Senior Member
Mar 10, 2008
4,043
383
Ealing
It might show the icon but does it show its charging?

Sent from my SPH-P100 using XDA Premium App

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
 

sys73r

Senior Member
Mar 29, 2011
54
4
My sgt gets charged when plugged to the mac, it is slow but works.

Sent from my GT-P1000 using XDA App
 

4exess

Senior Member
Apr 3, 2011
224
68
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

Sent from my GT-P1000 using XDA App
 
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deadsimple

New member
Dec 16, 2010
1
0
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 ...
 
Last edited:

3Flight

Member
Feb 25, 2009
46
5
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.
 
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1jz68u

Senior Member
Oct 4, 2010
50
2
If you turn the tab off it will charge using any usb charger

Sent from my GT-P1000 using XDA App
 

mtmello

Senior Member
Feb 24, 2010
203
22
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

Sent from my GT-P1000L using XDA App
 

texasreb

Senior Member
Nov 26, 2010
56
0
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

Sent from my GT-P1000L using XDA App


Just get the galaxy tab usb adapter from amazon uk and you can cbarge from any charger.
 

leapinlar

Senior Member
Oct 18, 2006
8,873
3,876
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.

Sent from my SCH-I800 using Tapatalk
 

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  • 11
    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.
    2
    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.


    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
    2
    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.
    1
    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.
    To charge your GT with any usb charger you have to make a little adapter.

    How can you do that? You need an extra device adapter? Please explain.
    1
    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.