Database Users

Faster USB charging?

Just got a new motheboard which has high output USB charging for iPhones, pads etc.
Can this work on N1 ?
http://gigabyte.com/MicroSite/185/on-off-charge.htm
edit: driver link is at the bottom for all the hackers. Hopefully its just changing string from apple to android hehe

kazprotos said:
Just got a new motheboard which has high output USB charging for iPhones, pads etc.
Can this work on N1 ?
http://gigabyte.com/MicroSite/185/on-off-charge.htm
edit: driver link is at the bottom for all the hackers. Hopefully its just changing string from apple to android hehe
Click to expand...
Click to collapse
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.

Dear lord what a crappy reply. Stick to disney mate.

It should, it basically just converts the USB port from .5 amps to 1 amp, like a wall charger.

elkyur said:
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.
Click to expand...
Click to collapse
WTF??? May want to lay off the halucinogenics

elkyur said:
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.
Click to expand...
Click to collapse
lol I seriously hope this is a joke!
I agree with JCopernicus, it should definitely work.

I installed the software in the first post but it still charges very slow compared to wall outlet

Slightly OT, but I've got a USB adapter that plugs into the wall that came with my iphone and when I plug the N1 USB cable into this to charge the N1, it still charges very slowly compared to using the proper wall adapter, why is this? Does this iphone adapter restrict the voltage or something?

Generally, "charger detected" is a circuit that has USB data pins shorted together. So when the phone's USB device probes the lines and detects them shorted, it knows it's connected to a power supply.
But since USB max current spec is 500mA, the current draw is restricted - either by the phone or by the supply.
There might be some other connectivity trick that allows the phone to know it can draw x2 current from the socket and won't damage anything. Most phones probably don't limit the current draw and count on the board to do it. Some boards don't limit the current output, or limit it higher. And the fast chargers provide pulsing voltage - which isn't like USB.
So for the board to be able to charge the device, it needs to detect a device that can use pulsing voltage, and enable such voltage on the socket. It doesn't detect Nexus as such a device, I believe, and that's why the charging is slow.

Faster charging with USB
Building on Jack_R1's response, I believe that the phone is limiting the charge rate. You can make the phone "realize" it is connected to a charger rather than a data connection by shorting the 2 middle USB pins together. I have done this in several car chargers, and the N1 About/Status shows charging (AC), which is the faster charge mode. While you can short the pins in the larger end of a dedicated USB cable, if you can disassemble the connector, I found it much easier to open the charger itself to short the pins.

i also have a gigabyte mobo that has this feature but i havent gotten around to test it out yet. I dont think it would work because the feature is software based and will only bump up the voltage if the program detects an iphone connecting to your computer. Gigabyte doesnt want to be liable if they bump up voltage on every device you plug in and fry something.
btw I have tried charging my n1 from my computer and its extremely slow. started charging at around 5pm on sunday and at 11pm it went from about 23%-97% lol.

Yes, USB charging is very slow. It's actually good for the battery, though.

Maybe someone with some know how can look at the driver files for this 3x tech and see how it checks if its an Apple device. Then fool the check and presto!
Shame I don't know how to do any of this

There is a simple hardware (don't worry, it's on the cable) mod for faster charging; however, make sure the phone has good air vent (it means NO CASE when charging).
1. modify your microUSB cable, disconnect the data connector the A (host) plug, then shorten the data connector to the B plug. (This can charge N900 properly, and speed up n1 charging).
2. modify your powered (with AC adapter plugged) USB hub. Simply shorten the #2 and 3 connectors on USB jack. Make sure you cut the copper strip going to the chip or malfunction may occur.
These modification can greatly speed up the charging, but phone will produce a lot of heat (that's why you must have the phone "naked").

I don't understand this. If the phone + battery are capable of being charged at 1000 mAh from the wall charger then why need extra cooling when asking for 1000 mAh from a PC USB socket?
Mine's still defo getting only 500 mAh from the PC USB despite it being able to give up to 2700 mAh for iPad!!! All I want is my 100 mAh charge.

Because what he suggests isn't a proper charging but rather removal of slot power control, and will damage the battery / phone, if succeeds.
Proper charging at 1000mAh requires pulsing voltage - his hack doesn't provide that. Your MB does, but it requires SW intervention to turn it on.

So can someone brew the intervention ?

martinl1030 said:
i also have a gigabyte mobo that has this feature but i havent gotten around to test it out yet. I dont think it would work because the feature is software based and will only bump up the voltage if the program detects an iphone connecting to your computer. Gigabyte doesnt want to be liable if they bump up voltage on every device you plug in and fry something.
btw I have tried charging my n1 from my computer and its extremely slow. started charging at around 5pm on sunday and at 11pm it went from about 23%-97% lol.
Click to expand...
Click to collapse
They are not doing anything to the voltage, simply allowing more current to pass.
And as said in this thread, any typical data USB cable will charge very slowly. And most standard USB ports charge well less than the max specced 500mAh, in fact my subnote at work I found charged my old phone at around 150mah one time when I was dead and needed to top off and it's all I had available.

i'm not sure of the pinout on the micro USB port but i'm pretty sure that that the Mini USB-B port that was used on phones like the G1 used shorting the -Data pin to the unused 5th pin (actually pin 4 on the connector pinout) to activate AC charge mode. some devices actually require a resister of a certain value to be placed across them to work(i know older motorola phones did like IDEN's)
one thing people often forget but should not forget is that current is drawn from the device using power. its not forced on the device. voltage is forced on a device and while a variance is usually ok for devices depending on how they were designed generally its not a good idea to exceed +1.5v on any low power DC device. 120V AC devices are designed to actually work in a much wider range like 100-130V but thats because of the power supply/nature of AC power. it always varies and in japan they use 100v 60hz AC so many electronics power supplies are designed to work in the full range to save costs and only have to make 1 unit for all (same deal with 220-240 switches on PC power supplies)
the reason why you don't want to do this mod is you could damage you PC's motherboard by pulling too much current from its circuits. USB spec is 500ma. performing this type of mod on a power adapter (car or AC) that does not get recognized as an AC charger by the phone is a safer way to go. worst case senario is you break the charger (unless you mess up on the pinout then you could damage you phone too though)

Need some help from someone who knows legit electronics(diodes, resistors, etc.)

So, i'm trying to add in a usb microsd adapter to my Kindle Fire.
Threads before I started, just discussing ideas:
KF forum: http://forum.xda-developers.com/showthread.php?t=1615055
Hardware hacking forum: http://forum.xda-developers.com/showthread.php?t=1615059
Now, I just about completed the project, but I dropped the motherboard and broke it while soldering a wire onto it. I've just bought another KF off of ebay and will continue at that point, but while i'm waiting I need some advice/help.
I've made a diagram of what i'm going to do. It's pretty horrible, but I think it's understandable.
Few questions that go with the diagram:
*DC only flows one way, do I need the diodes?
*If I should use the diodes will these work? (max output they would need to withstand would be 7v and 1A cause of the wall charger)
*The wall charger puts out 1000mA(1A) when charging. USB puts out 100mA, would that 1A ruin the adapter since it's designed for USB? If so, should I use some resistors?(Unsure cause they would change the regular, lower output to the adapter)(Or the resistors could be put into the charger)
*More questions/concerns on the diagram
Diagram:
Taken off because it was incorrect.

I'm still a bit fuzzy on what's going on here.
I'm not sure what the (2) 3.7V batteries and the 4.4V boards are.
Is that the stock Kindle Fire power supply that you are showing?
Th first question: Have you gotten the USB SD card to work normally plugged in externally?
If not, have you gotten the USB SD card to work through a powered hub?
All the diodes on the black lines are drawn backwards.
You don't need any diodes there or even a reed switch on the black line.
You might have a problem activating the 4 (remaining) reed switches simultaneously and reliably.
If you've never seen voltage out of the KF USB connector, that means that you've not gotten it into USB host mode.
Oh, of course the KF has a single 3.7V battery so I don't know what that whole right side is doing.

Renate NST said:
I'm still a bit fuzzy on what's going on here.
I'm not sure what the (2) 3.7V batteries and the 4.4V boards are.
Is that the stock Kindle Fire power supply that you are showing?
Th first question: Have you gotten the USB SD card to work normally plugged in externally?
If not, have you gotten the USB SD card to work through a powered hub?
All the diodes on the black lines are drawn backwards.
You don't need any diodes there or even a reed switch on the black line.
You might have a problem activating the 4 (remaining) reed switches simultaneously and reliably.
If you've never seen voltage out of the KF USB connector, that means that you've not gotten it into USB host mode.
Oh, of course the KF has a single 3.7V battery so I don't know what that whole right side is doing.
Click to expand...
Click to collapse
The battery is made up of two 3.7v batteries, they just stuck them together and put a board there to control the power flow or whatever. I said it's lowered to 4.4v cause normally when two batteries are put together their voltage gets added together, but that 4.4v is coming from the very end pins, there are 10 total. I get 4.4v when trying the other pins too, so since i'm only connecting it to one set of pins i'm just going with 4.4v.
No, I haven't. I have not been able to successfully get USB host working at all, even with a USB host cable. I don't have a powered hub, but I tried taking the power from a USB port on my computer and that didn't work either. Other people have it working though, some with powered hubs, and a few without.
It might have just been my Kindle, so i'll see when I get the other Kindle I ordered.
I thought I was doing them backwards, I know how they go on physically, but I wasn't sure about on paper.
I'm not sure that i'll need all the reed switches, I may just need two; one to disconnect the ID(blue wire) from the back, and one to disconnect one of the data lines. I wasn't able to experiment though since I never got USB host working.
I tried measuring the voltage directly on the board and from the USB host cable and didn't a reading from either.(When I measured on the board I shorted out the ID an GND wires like they are on a USB host cable)
What I was trying to do with the battery there was prevent power from the charger going directly to the battery, that would be bad. So I do need at least one diode on each line there, but the other two I added cause I didn't want any extra power to be wasted. Of course, it doesn't make much sense to me(not sure what I was thinking), that's why I asked if it was necessary.
Picture of the battery and the board connected to it. I took it apart and removed the second one to move it over and resolder it so there was space down the middle for the wires. The adapter will be at the top where the speakers are.
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This whole idea has lots of problems.
Taking power directly off the battery is not a good idea for many reasons,
the least of which is that many (most?) USB devices won't work on 4.4 volt.
Throw in a silicon diode and you're down a further 0.7 volts.
Ok, you could make it a Schottky diode if you want.
You're still going to have to disconnect both data lines to get this to work,
unless you are planning to only use the external USB connector for charging.
Using host mode, the power should be coming out of the USB interface.
As mentioned, if you don't have it there, it's not working.
Here's a sequence of a Kindle Fire teardown: http://www.ifixit.com/Teardown/Kindle-Fire-Teardown/7099/1

Renate NST said:
This whole idea has lots of problems.
Taking power directly off the battery is not a good idea for many reasons,
the least of which is that many (most?) USB devices won't work on 4.4 volt.
Throw in a silicon diode and you're down a further 0.7 volts.
Ok, you could make it a Schottky diode if you want.
You're still going to have to disconnect both data lines to get this to work,
unless you are planning to only use the external USB connector for charging.
Using host mode, the power should be coming out of the USB interface.
As mentioned, if you don't have it there, it's not working.
Here's a sequence of a Kindle Fire teardown: http://www.ifixit.com/Teardown/Kindle-Fire-Teardown/7099/1
Click to expand...
Click to collapse
Taking power straight from the battery is only a temporary solution, the devs working on the 3.0 kernel is working on fixing the OTG issues and trying to remove the kernel limit of 3v. Also, from what I understand there are other issues that the KF is having regulating the voltage out, people report that below 50% battery USB host stops working.
So, if the issues get fixed i'll just disconnect the battery, or, as I said before, it may have just been my Kindle. I got it used & broken and fixed it myself, so it may have been damaged more than I was aware. I would be able to provide more definitive answers if I had something to experiment with, but I won't have the other Kindle for a few days.
Also, since i'll have a second battery now, i'm not as worried about the battery being damaged.
I do realize that the diodes drop the voltage by .7v, but people who have USB host working report that the KF is putting out 3.3v, and some people have gotten certain flash drives and other devices to work off of that. I believe the microsd adapter I have will work off of that lower voltage.
I only charge using a wall adapter, and charging did work for me as long as the ID and GND cables were separated. My main concern is that adb and fastboot work since i'll just be transferring files to the Kindle and the sdcard with FTP. Which, if adb works so will mass storage, so...
Without using the battery it's just and internal OTG USB host set up with a switch/es, so in theory it should work.
I also don't need and diodes if it's not connected to the battery. I was just hooking it up to the battery cause I wasn't getting any power from the Kindle.
As for the reed switches not working reliably, I did read something before that said that they might screw each other up if they were all right next to each other. What if they were lined up end to end, would they interfere with each other like that? If they do work properly end to end all I need is a custom, long, slender, and rectangular neodymium magnet.
Again, I didn't really have much time to experiment since gravity and I screwed up my motherboard. I had just done some physical modding to the housing and framing to make space for everything, and done some testing on the voltages that it was putting out.
Also, thanks for the help and advice

Ok, here's what I was planning on doing without the battery, any problems now, besides the potential issues with the reed switches?

Ok, the TWL6030 used in the KF uses an LDO regulator for VBUS on USB for OTG
and is speced for 3.3V at 35 mA
http://www.ti.com/lit/ds/symlink/twl6030.pdf
The Nook Touch that I have uses a TPS65921 (a/k/a TWL4030) which uses a charge pump
and is speced for 5.0V and guaranteed for 50 to 100 mA depending on battery voltage.
http://www.ti.com/lit/ds/swcs048f/swcs048f.pdf page 16
I've seen some devices that won't even work at 4.5V
Keyboards generally draw about 5mA.
I've seen audio adapters at 25 mA.
Some thumb drives take a lot of current.
Keeping the red connected all the time may or may not be a problem.
An inactive USB device should not be drawing much (any?) current, but you can never tell.
Bottom line, I don't think that the KF is a very good candidate for stand-alone OTG.
I'd use a powered (and back-powering) hub if I owned a KF.

I don't know what's going on here.. but I corrected your power supply in the schematic above.

Renate NST said:
Ok, the TWL6030 used in the KF uses an LDO regulator for VBUS on USB for OTG
and is speced for 3.3V at 35 mA
http://www.ti.com/lit/ds/symlink/twl6030.pdf
The Nook Touch that I have uses a TPS65921 (a/k/a TWL4030) which uses a charge pump
and is speced for 5.0V and guaranteed for 50 to 100 mA depending on battery voltage.
http://www.ti.com/lit/ds/swcs048f/swcs048f.pdf page 16
I've seen some devices that won't even work at 4.5V
Keyboards generally draw about 5mA.
I've seen audio adapters at 25 mA.
Some thumb drives take a lot of current.
Keeping the red connected all the time may or may not be a problem.
An inactive USB device should not be drawing much (any?) current, but you can never tell.
Bottom line, I don't think that the KF is a very good candidate for stand-alone OTG.
I'd use a powered (and back-powering) hub if I owned a KF.
Click to expand...
Click to collapse
Thanks for the info, I cut open a cable and plugged it into my computer with a resistor hooked up to it and got the voltage down to about 3.4v and the adapter that i'm using still ran and was recognized. I'm unsure about the current though.
It's not really OTG if it has to be hooked up to a separate power supply :/
AdamOutler said:
I don't know what's going on here.. but I corrected your power supply in the schematic above.
Click to expand...
Click to collapse
I don't understand why i'd need a 5v regulator on the battery when it's only putting out 4.4v? (Again, current-wise i'm unsure)
Also, the ID wire(blue) needs to be connected to the GND to activate USB host mode, it tells the device that it's a master and not a slave.
And I don't know if you read my previous posts, but I may not even be using the battery if I can get USB host working like everyone else. And the diodes were there cause I didn't want power going directly to the battery since it could mess it up.

Well, your circuit is wrong in a bunch of different ways so I redesigned it.
0. USB requires 5V regulated power.
1. the ground diodes are pointing the wrong way so the power would not flow.
2. When charging the battery you'd kill your device
3. zener diodes breakover at a certain voltage, not regulate. Those zener would just prevent any voltage from flowing. You'd want a Silicone Controlled Rectifier.
4. The 2 extra diodes do nothing at all in your circuit.
5. Each diode drops .7V. Your circuit effectively uses 4 of them between power and ground from the battery. so, by the end of your circuit, the microSD adapter gets 1.6 volts.... no where near what's required to run the device.
So, I corrected the circuit.
Didn't read that you were using any other method, still havn't.. Just wanted to correct the circuit in case someone else tries to do it.

I built my own car charger using a similar circuit. It's the same thing you'll find in a powered usb hub, although they may use diodes to prevent a backflow of power into the computer.

AdamOutler said:
Well, your circuit is wrong in a bunch of different ways so I redesigned it.
0. USB requires 5V regulated power.
1. the ground diodes are pointing the wrong way so the power would not flow.
2. When charging the battery you'd kill your device
3. zener diodes breakover at a certain voltage, not regulate. Those zener would just prevent any voltage from flowing. You'd want a Silicone Controlled Rectifier.
4. The 2 extra diodes do nothing at all in your circuit.
5. Each diode drops .7V. Your circuit effectively uses 4 of them between power and ground from the battery. so, by the end of your circuit, the microSD adapter gets 1.6 volts.... no where near what's required to run the device.
So, I corrected the circuit.
Didn't read that you were using any other method, still havn't.. Just wanted to correct the circuit in case someone else tries to do it.
Click to expand...
Click to collapse
AdamOutler said:
I built my own car charger using a similar circuit. It's the same thing you'll find in a powered usb hub, although they may use diodes to prevent a backflow of power into the computer.
Click to expand...
Click to collapse
*If it requires 5v then how do devices run with less with USB host on other people's KFs?
*I'm aware that the ground diodes are the wrong way, I asked in my og diagram, and mentioned in a previous post that I know how they go on physically, just not in a diagram.
*That's why I had the diodes, to prevent messing up the battery and device
*I still don't understand how/why it needs to be regulated when it's only 4.4v, it's not over 5v.
I know what zener diodes are, all I would need is to prevent power going straight into the battery, and that's what the diodes would do.
*I wasn't going to use those extra two diodes on each battery line unless someone said that it did something, it was suggested to me by someone who has less electronical knowledge than me and I figured it doesn't hurt to ask.
*And with the 3.3v from the Kindle and 4.4v from the battery minus the 2.8v required for four diodes it equals 4.9v, which should work, but hopefully I don't have to use the battery.
Also, if you look at the picture in my post here it shows exactly what a OTG USB host cable does minus the switches. All I did was add the battery and diodes to prevent power from the charger going into the battery and power from the battery going into the charge port. In theory that should work out. And like I said before, hopefully I don't need to use the battery at all.
I removed the picture in the first post since it was incorrect; while I doubt anyone is going to try it at this point, I understand your sentiment.

Look, im not saying my way is totally up to standards, but it comes much closer than yours with fewer parts, less work and i gaurantee it will work. The proper way is to buy a powered hub and connect to that. If you dont want feedback, dont post in a discussion forum.
Im done wasting my time on this thread. Youre doing it wrong.

AdamOutler said:
Look, im not saying my way is totally up to standards, but it comes much closer than yours with fewer parts, less work and i gaurantee it will work. The proper way is to buy a powered hub and connect to that. If you dont want feedback, dont post in a discussion forum.
Im done wasting my time on this thread. Youre doing it wrong.
Click to expand...
Click to collapse
No need to get all upset bro, i'm just replying to what you've said(Like you said, discussion forum). You said you didn't read any previous posts, and it was obvious, you kept saying things that had already been brought up. And you say things like "Those zener would just prevent any voltage from flowing" when I was saying that was what I was trying to do anyways. Your comment implies that you think that I shouldn't use them, but with no explanation as to why not.
It's not that I don't want feedback, but you keep saying i'm doing it wrong, but you're not answering the questions that I ask. You're just saying "My way is right, your way is wrong," basically.
I repeatedly asked why it needs to be regulated when it's already less than 5v.
I also asked "If it requires 5v then how do devices run with less with USB host on other people's KFs?"
And I realize I didn't post this, but my next question was going to be, with the regulator there I would still need to put the diodes in to prevent power from the battery from going into the charge port and power from the charger going directly into the battery, correct?
Tl;dr:
You're right, you're wasting your and my time because you're not answering my questions, you're not explaining why your way is correct, and you keep bringing up things that were already discussed that I know about.

aaricchavez said:
If it requires 5v then how do devices run with less with USB host on other people's KFs?
Click to expand...
Click to collapse
Um, luck? Sure, a lot of devices are not picky about power.
The specification for USB is 5.0 V
Some devices may not have enough voltage to run at 3.3 V
Some devices may not have enough current to run at 35 mA
Some may simply not detect the presence until it rises over a threshold of 4.5 V
An SD card all by itself uses a nominal 3.3 V
The USB interface circuit is a separate issue.
aaricchavez said:
And with the 3.3v from the Kindle and 4.4v from the battery minus the 2.8v required for four diodes it equals 4.9v
Click to expand...
Click to collapse
The math may be correct, but unfortunately the circuit is not in series.
The voltages just don't add up that way.
You'd need a "floating" battery (not the built-in one) to make the voltages add.
Getting a higher voltage from somewhere and using a 5 V voltage regulator would work.
However, you might need up to 7 V input because your garden-variety regulator has a "dropout voltage" of about 2.0 at full current.
That's why there are special "low dropout" (LDO) regulators designed for such cases.
Still, they can't make more voltage than what they take in.
For that we use charge pumps or boost regulators.
Both of those are active switching devices.

aaricchavez said:
I repeatedly asked why it needs to be regulated when it's already less than 5v.
I also asked "If it requires 5v then how do devices run with less with USB host on other people's KFs?"
Click to expand...
Click to collapse
Sorry didnt read all of the posts, butfor this you can use simple step-up converter.
I have solar charger also with li-ion battery which can provide max 4,22 V and I need 5 Volts.
I bought this module on ebay:
http://www.ebay.com/itm/DC-DC-Conve...175?pt=LH_DefaultDomain_0&hash=item4165891a1f
Works great, provides nice clean 5V output, max is about 2 Amps, even they are telling more... Could also post my complete solution photo if you want

Renate NST said:
The math may be correct, but unfortunately the circuit is not in series.
The voltages just don't add up that way.
You'd need a "floating" battery (not the built-in one) to make the voltages add.
Getting a higher voltage from somewhere and using a 5 V voltage regulator would work.
However, you might need up to 7 V input because your garden-variety regulator has a "dropout voltage" of about 2.0 at full current.
That's why there are special "low dropout" (LDO) regulators designed for such cases.
Still, they can't make more voltage than what they take in.
For that we use charge pumps or boost regulators.
Both of those are active switching devices.
Click to expand...
Click to collapse
What's the difference between the built in battery vs an outside battery that would make it add up?
Adding another power source would basically end up being the same as getting a powered hub.
So what Helium, the poster below you, said should work with the 3.3v that the KF already puts out?
HeliumX10 said:
Sorry didnt read all of the posts, butfor this you can use simple step-up converter.
I have solar charger also with li-ion battery which can provide max 4,22 V and I need 5 Volts.
I bought this module on ebay:
http://www.ebay.com/itm/DC-DC-Conve...175?pt=LH_DefaultDomain_0&hash=item4165891a1f
Works great, provides nice clean 5V output, max is about 2 Amps, even they are telling more... Could also post my complete solution photo if you want
Click to expand...
Click to collapse
I would like to see the photo, if you don't mind.
This one should work as well, correct? http://www.ebay.com/itm/DC-DC-3V-to...932?pt=LH_DefaultDomain_0&hash=item3a722f7ccc

aaricchavez said:
What's the difference between the built in battery vs an outside battery that would make it add up?
Click to expand...
Click to collapse
Many many ..
Power outputs form every mobile devices are not designed to provide big current. It is many times about 50-100 mA, which is sufficient for flash sticks,keyboards or mouses but not for e .g. hard drives.
If you connect step-up converter to for example 3,3V and 100mA, on output you will get 5V 50mA - this is really not sufficien for even mouse...
But if you use battery insted, it can provide huge current - normally 2000mA max. So if you connect battery to converter you will get 3,7V 2000mA and on output 5V 1400mA. Which could be usable even for low power 2,5" hard driver. Also battery has bigger voltage, so it means, that efficiency will rise up a little.
aaricchavez said:
So what Helium, the poster below you, said should work with the 3.3v that the KF already puts out?
Click to expand...
Click to collapse
Yes, look up in this post
aaricchavez said:
I would like to see the photo, if you don't mind.
Click to expand...
Click to collapse
Here there are - as you can see. I am charging my phone from standart li-ion battery from GPS with standart 5V USB
aaricchavez said:
This one should work as well, correct?
Click to expand...
Click to collapse
Yes, could. But I recommend that I posted before - it has bigger mosfet package, which allows about 0,5W thermal dissipation. On your module are SMD transistors, which can dissipate only 0,1W and are very sensitive to aḿbient temperature. I dont trust SMD components in power solutions.

I'd actually recommend keeping the boost regulator on the smaller side.
Besides the space consideration, it would be nice if there were some current limiting.
I just measured the current draw on a 4GB microSD in a IOGear USB adapter and it was 45 mA.
The wireless mouse dongle that I measured was 15 mA.
I don't have any wired mice to measure, but I'd guess that they would all be around that.

Renate NST said:
I'd actually recommend keeping the boost regulator on the smaller side.
Besides the space consideration, it would be nice if there were some current limiting.
I just measured the current draw on a 4GB microSD in a IOGear USB adapter and it was 45 mA.
Click to expand...
Click to collapse
Sure, but you wrote, that his device provides 35 mA max, so it wont be enought for most flash drives. Besides that - you measured in low power (3,3V) or high power (5V) USB mode? Because I expect 5V mode so it means than in 3,3V will be much more miliamps...
Anyway, with boost module it will enable him to use almost everything which has drivers. Not only tiny consumption devices, it will be full equipped active host hub also could be connected with switch as emergency charger...

[Q] N7 discharging when plugged in

Lately – I’m not sure when this stated, my Nexus 7 (running 4.4.2) has been charging absurdly slow. I’m talking 20%-30% in a span of 24 hours. It’s like it’s hooked up to a trickle-charge. I’ve tried 2 different OEM cables and 2 different OEM chargers (I had the one that came with it, and I ordered an official Asus OEM replacement charger with cable as well, to have as a spare).
I downloaded Battery Monitor Widget and while it sees it as plugged in via AC, the charge rate is -9ma (in other words, while plugged in, running nothing but the battery monitor, instead of actually charging, it simply reduced the discharge rate from negative 718ma to negative 9ma).
The only thing I can think of is this: as I understand it, USB AC adapters capable of “fast charge” (2ma) first test the device to see if it’s compatible, to avoid potentially over-charging the unit. Perhaps my device is not properly responding to this test? Perhaps that’s why it’s not providing enough juice?
Or maybe someone else has some better insight and can educate me. I’m certainly open to learning. Any ideas?

WraithTDK said:
The only thing I can think of is this: as I understand it, USB AC adapters capable of “fast charge” (2ma) first test the device to see if it’s compatible, to avoid potentially over-charging the unit. Perhaps my device is not properly responding to this test? Perhaps that’s why it’s not providing enough juice?
Or maybe someone else has some better insight and can educate me. I’m certainly open to learning. Any ideas?
Click to expand...
Click to collapse
[apologies in advance for a long-winded reply; hopefully some of it will be useful to you]
The OEM charger should be capable of 2 A (not 2mA).
Dumb chargers don't "talk" to the tablet. (Well, except for Apple USB dumb chargers - Apple violates the USB spec with their proprietary hardware, and that raises the meaning of "dumb" to a whole new level).
The tablet tries to draw what it wants, and if the wall charger is capable of supplying that current, everything will be fine - meaning, that the output voltage of the charger will be stable (near to 5V). If the tablet tries to draw more current from a charger than the charger is designed for, what usually happens is that the output voltage of the charger will start to droop down. (Sometimes, even worse things can happen, such as the voltage coming from the charger will start to oscillate.) This will have the effect that the voltage drops down to the point where it is barely larger than the voltage from the battery, and so the current flowing out of the charger gets limited that way.
But you shouldn't have this problem as you have at least two OEM chargers, and more than one cable, suggesting that your difficulty is with the tablet somehow.
I note (from your post) that you can observe the actual charging current; this suggests that you have a custom kernel on your tablet, as the stock kernel doesn't have the BQ27541 patches which allow current monitoring (only battery voltage and percent charge).
Here's the reason why I mention this. (Oh boy, get yourself a beverage, this is a long story).
I was going to be making some long drives (>13 hr) and I wanted my N7 in the vehicle, WiFi tethered and active (Google Nav and so forth) As you have observed, when you have the tablet running and are poking away at the screen, it can draw anywhere from 300 mA to more than 1000 mA, depending on how many cores are alive, which CPU frequency is in use, the screen brightness, streaming activity, etc.
And unfortunately...I was in a hurry: I couldn't wait for a car charger to be delivered following an online purchase. And all the local electronics stores seem to only sell high-capacity car chargers that are "Apple Compatible", which is marketing speak for "violates the USB spec". The N7 expects compliant behavior from chargers.
So, I bought two of those "Apple Compatible" car chargers from different manufacturers, and also bought a micro-USB cable that I could hack. I opened up the cable, clipped the D+/D- wires, connecting them together on the "Nexus 7" end of the cable, and left them open on the charger side (open but insulated of course). This has the effect of preventing the N7 from thinking there is a data connection present - the Apple chargers twiddle those D+/D- lines a little bit, and that prevents the (USB spec-compliant) N7 from thinking there is a dumb charger on the other end of the cable.
I wanted to be sure that what I had was actually working correctly, and if either of those two car chargers really would provide enough current, so I installed a dev kernel that has the BQ27451 battery current monitor patches in it. I think several of the dev kernels have this; I used M-kernel.
OK, so far so good.
The next step was to crank both the min and max CPU clock limits way down (300 Mhz iirc), turn on the "performance" governor and turn the screen brightness all the way down. I may have even used Trickster Mod to set Max_Cores to only 1. This was done so that the tablet would draw a smallish and constant current. That way, when I plugged in the car charger, I would actually know what the total charger current was - the sum of the (absolute) values between the unplugged state (discharging) and plugged in (charging)** If you leave the CPU frequency controls in their normal state, the amount of current the tablet draws can jump all over the place depending on tablet activity, and then it would be hard to know the total current the charger is actually producing. (It is the SUM of the battery current displayed plus whatever the tablet is drawing).
When I did the above, my N7 (grouper, WiFi off) was drawing just under 300 mA of current from the battery in the unplugged condition.
Still with me? (it gets better, trust me).
So, what I observed was that, yes, one of the two chargers was better than the other; I could get get the monitored battery charging current up to 1400 mA with one, and maybe 1100 mA with the other. (That's total current from each charger of about 1.7A or 1.4A respectively after adding in the 300 mA the tablet is drawing)
Finally though, an explanation of why this is relevant to you:
When the tablet was plugged in to either charger, the current would not immediately jump up to the maximum value; instead, it would sometimes takes minutes or more for the current to jump up to that maximum value!
It would, however immediately jump up to about 800 mA total current right after plugging the charger. That's better than a 500 mA computer USB connection, but if the tablet is active, it's no guarantee that the tablet will gain any charge - as in your situation.
So why the delay? To be honest, I don't really know. In my panic to get ready for my travel, I only spent a little bit of time fooling with it - for a while I had a hypothesis that the kernel was doing *something* that made the current pop up to its full 1.7A value only after the tablet had left a deep sleep state. The good thing was that once the current stepped up to the full value, it would stay there despite the level of activity on the tablet.
[size=+1]The point is that the maximum charging current condition seems to be dependent on some condition(s) happening which is under control of the kernel - it is not just an "analog" behavior that happens as soon as you plug the charger in.[/size].
So I suppose it is possible that you simply have a configuration where the operating trajectory that your tablet passes through does not trigger the right conditions in the kernel to command the SMB chip (USB interface controller) to max the current out close to the 2A limit.
You might want to try an experiment where you:
- Observe the charging rate with the tablet completely turned off. Should be about 100% in 150 minutes (2.5 hrs) or about 6-7% every ten minutes. Note that because the battery is 4.235 A-h capacity, that works out to a charging current of at least (4.235 A-hr / 2.5 hr) = 1.7 A. (It is probably greater than that due to charging losses).
If your tablet charges at about this rate when it is off, then nothing is wrong with your charger, cable, battery, or SMB chip, and it points a finger at your kernel's code - and possibly other things like applications holding wakelocks which prevent the tablet from entering deep sleep.
I won't go so far as to claim that it is "coming out of deep sleep" that triggered the M-kernel to twiddle the SMB chip so it would draw 2A; in all my experimentation, I couldn't faithfully reproduce the behavior. The good news was that that it would eventually (within a few minutes, possibly due to the tablet sleeping) ramp completely up and then stay there.
Anyway, I hope this gives you some food for thought and maybe some experiments you can run to narrow down the problem.
- What kernel are you using?
- Does your tablet ever enter deep sleep? (I don't mean simply that the screen is off - it is a state where the hardware is placed in a low-power state where even the memory bus is no longer operating. A wakelock might prevent this from happening, but in any event you should be able to observe this in the kernel log - the clock values get wonky and you might see a message about "G" state)
- Does your tablet charge even a little bit when the screen is off?
** I sort of recall that that "Current Widget" app always displays a positive value for current, but changes the display color red/green depending on whether the tablet is discharging (red) or charging (green). Something to watch out for.
.

Kernel: It's rooted, but otherwise completely stock. Battery Monitor Widget doesn't seem to have an issue display the charging rate (and yes, I meant 2A, not 2ma).
Sleep mode: It should; I have one of those cases whose covers are supposed to put it in sleep mode. It DOES charge; but it does it at a snail's pace; a battery info app has it at 30% over the span of 24 hours with it never being touched during that time.
I turned it completely off 3 hours ago at 37% and I just turned it on to 76%
Unfortunately, Current Widget is not compatible with the N7.

WraithTDK said:
Kernel: It's rooted, but otherwise completely stock. Battery Monitor Widget doesn't seem to have an issue display the charging rate (and yes, I meant 2A, not 2ma).
Click to expand...
Click to collapse
It actually displays instantaneous current? Maybe I should restore a 4.4.2 ROM and see if the newer stock kernel has those BQ27541 patches.
WraithTDK said:
Sleep mode: It should; I have one of those cases whose covers are supposed to put it in sleep mode.
Click to expand...
Click to collapse
Well, "screen off" is not equal to "deep sleep". The tegra3 has multiple low-power modes, but the one I am thinking of is really low power - kind of like a "suspend" state for PCs. If there is an application holding a wakelock, the tablet will never enter deep sleep. (As I mentioned, the "deep sleep" mode is very near to the tablet being completely off - the lpRAM is still drawing a little bit of current (it is in self-refresh mode) ). When my N7 sleeps, it charges nearly at the same rate as when it is turned off. (But, see below; in light of that I don't think this is your problem)
WraithTDK said:
It DOES charge; but it does it at a snail's pace; a battery info app has it at 30% over the span of 24 hours with it never being touched during that time.
I turned it completely off 3 hours ago at 37% and I just turned it on to 76%
Click to expand...
Click to collapse
39% in 3 hrs? Hmmm. If things were linear, that would be: 0.39*4.235 / 3 = 551 mA.
You are right, that isn't very good at all. Your tablet will discharge if you are using it even though it is plugged in.
Well - that "tablet off" charging test is pretty diagnostic - the kernel and OS are not even running, so they can't be altering anything. So maybe they can't be blamed for anything either.
But, that Summit Microsystems SMB347 chip is sitting there acting as the battery charger, even when the tablet is "off". Maybe it has something stateful in it (like a few non-volatile memory registers) that could have been altered by past activity on the tablet. Summit doesn't allow datasheet downloads without a NDA, so I don't know.
When the N7 is fully turned off, there is still something tiny running - otherwise, how would that "charging animation" get painted on the screen when you plug the tablet in when it is off? I don't know if that is something in the tegra3 miniloader or just a low-power personality of the bootloader; hard to know really. I guess I am speculating whether something in the bootloader could have "programmed" the SMB chip, but the only thing I remember seeing here (on XDA) is a toggle via a fastboot OEM command that causes the tablet to boot up as soon as power is applied - the guys who do car installs use that.
Well, I'm sort of out of ideas. It sounds like you have tried the obvious stuff already. Do you have any reason to believe the USB port has an intermittent connetion? Or maybe that the battery itself has an intermittent or resistive connection at its power connector?
cheers

Had a very similar problem on my s3 and the problem was the microusb port on the phone
Sent from my SPH-L710 using Tapatalk

WraithTDK said:
Lately – I’m not sure when this stated, my Nexus 7 (running 4.4.2) has been charging absurdly slow. I’m talking 20%-30% in a span of 24 hours. It’s like it’s hooked up to a trickle-charge. I’ve tried 2 different OEM cables and 2 different OEM chargers (I had the one that came with it, and I ordered an official Asus OEM replacement charger with cable as well, to have as a spare).
I downloaded Battery Monitor Widget and while it sees it as plugged in via AC, the charge rate is -9ma (in other words, while plugged in, running nothing but the battery monitor, instead of actually charging, it simply reduced the discharge rate from negative 718ma to negative 9ma).
The only thing I can think of is this: as I understand it, USB AC adapters capable of “fast charge” (2ma) first test the device to see if it’s compatible, to avoid potentially over-charging the unit. Perhaps my device is not properly responding to this test? Perhaps that’s why it’s not providing enough juice?
Or maybe someone else has some better insight and can educate me. I’m certainly open to learning. Any ideas?
Click to expand...
Click to collapse
You might have an issue with your USB on your device. Mine was starting to charge slow but not quite to the degree as yours. I also found that my device would no longer communicate to any computer. If you have tried different cables & charger then you may have to RMA your device.

Asus Nexus 7 draining while plugged in to charge
My Nexus 7 was totally dead. Hit the power button and five blinks of a white LED. Plugged it in it went to 68% then next day it was 28% - 19% and on down. Before it got to zero I turned it off and took off the back. I noticed with the aid of a magnifying glass, that the soldered connections of the mini USB charging port were very possibly fractured. Having had experience at soldering, I added solder and reflowed the connections (about 4 or 5). I then plugged it in. For the first time since the beginning of this mystery I saw the battery icon actually indicating that it was charging. It was 100% within three hours. Haven't had a problem since.
I have been searching all over and found many ideas from - try another charger to - install another charging board. When you think about it, that connecter sees a lot of push and pull. If it is not soldered well and sturdy it's no wonder that it will fracture. I don't think there was enough solder on there to begin with.
If you do not know someone who can solder on a very small scale and want to brave this yourself, make sure you have a very small tip on the iron, not more than 700 degrees and some extra flux. You will most likely bridge a few connectors but keep brushing the tip of the iron away from the connections with flux added. You will get it eventually. Just don't burn the board. And clean it all with a brush and alcohol. Good luck.

Black screen with white streaks when powering up then black

I have been reading all the posts regarding the dreaded "black screen" issue. However mine doesn't seem to fit the bill
It has been left to discharge and wouldn't boot up. i plugged it in (wall charger) and left it for 24hrs. I tried to boot it up but all that comes on is the Google logo then i see some white video streaks then it turns black again
It is rooted and i tried to boot into TWRP but it shows the same streaks then it turns black again. I did press on the back where the connector was supposed to be and thinking would fix it but no success
I do not know what else to do.
Do i need a new screen? I wouldn't mind to replace it if i knew that was the problem but i am not sure if that is the case
Is there anyone that had a similar experience and can maybe share some ideas?
I would really appreciate it!!
Thank you

rainfactor said:
...regarding the dreaded "black screen" issue. However mine doesn't seem to fit the bill
It has been left to discharge and wouldn't boot up.
Click to expand...
Click to collapse
I was under the impression that that scenario is exactly the bill - the battery drains off to such a low voltage that the internal charge controller circuit doesn't work correctly at that low voltage, even when you put the device back on the charger, so you are stuck with a not-dead unit that won't turn on, and also won't take a charge. (But that hardware isn't dead - you just need a partial charge on the battery to get the charge circuit to start working again.)
The only recourse really is to get a *small* amount of charge on the battery by some means other than the built in charger, and then reconnect the battery to the tablet and put it on the charger to complete the charging.
There are disassembly instructions on here that take you through the steps necessary to get to the battery connector (it detaches and has a short run of wire between that connector & the battery so that should be convenient for attaching the battery to something else without removing the battery from the tablet). Use the search functions.
If you can borrow a voltmeter, the symptom will be obvious: a very discharged battery will have a terminal voltage around 3.0v (maybe less). Under normal conditions the battery voltage will rise to about 4.05v when fully charged (measured when disconnected from the charger) and be somewhere around 3v when completely discharged.
Don't do anything stupid (there are examples of that on here too). The charger that you use needs to limit the amount of current to a reasonable value, say less than 500 mA. The battery can tolerate up to about 1.8 Amps of charging current but you should use something far more conservative than that for safety reasons. And you are only trying to put a small charge on the battery (not completely charge it) so you don't need to use the fastest possible charging rate anyway.
Something incredibly cheap would be a USB cable (with the micro-B connector cut off) and a 1/4 watt, 100 ohm resistor connected to the positive supply line coming from a 5 volt USB wall wart charger. Even if the battery was a dead short, only 50 mA of current would flow and the resistor wouldn't burn up. If the battery was good but heavily discharged, you'd only be charging at a 20 mA rate - that would put a 10% charge on the battery in ~30 hours.
If you initially measured the battery and found it had a voltage of 2.5v or higher, you could use a 22 ohm, 1/4 watt resistor safely and charge the battery 10% in only 8 hours or so.
You can charge faster by using a resistor of a higher wattage rating, but 1/4 watt size are readily available and cheap.
The equation for power dissipated in the resistor is
P > V^2/R or
R > V^2/P = (Vs- Vb)^2/P
So for example in our case with Vs = 5, Vb = 3 and a 1/4 Watt (P) resistor, we would get
R > V^2/P = (Vs- Vb)^2/P = (5-3)^2/0.25 = 16 ohms.
The "dead shorted battery" worst case would be Vb=0 or
R > (5-0)^2/0.25 = 100 ohms
(so you can see where the numbers came from)
Anyway, that's my recommendation
- disassemble to the point of exposing the battery connector
-disconnect battery from tablet
- put battery on simple & safe charging circuit (+ terminal to resistor to + terminal, and - terminal to - terminal)
- let it sit for a while*
- reconnect to tablet and finish charging
- profit
* if you leave a live circuit unattended, even if it is only a 5v circuit, please please no exposed wiring or loose connections. Use tape and plastic straws for temporary insulation... or shrink wrap if you prefer a neater look.

bftb0 said:
I was under the impression that that scenario is exactly the bill - the battery drains off to such a low voltage that the internal charge controller circuit doesn't work correctly at that low voltage, even when you put the device back on the charger, so you are stuck with a not-dead unit that won't turn on, and also won't take a charge. (But that hardware isn't dead - you just need a partial charge on the battery to get the charge circuit to start working again.)
The only recourse really is to get a *small* amount of charge on the battery by some means other than the built in charger, and then reconnect the battery to the tablet and put it on the charger to complete the charging.
There are disassembly instructions on here that take you through the steps necessary to get to the battery connector (it detaches and has a short run of wire between that connector & the battery so that should be convenient for attaching the battery to something else without removing the battery from the tablet). Use the search functions.
If you can borrow a voltmeter, the symptom will be obvious: a very discharged battery will have a terminal voltage around 3.0v (maybe less). Under normal conditions the battery voltage will rise to about 4.05v when fully charged (measured when disconnected from the charger) and be somewhere around 3v when completely discharged.
Don't do anything stupid (there are examples of that on here too). The charger that you use needs to limit the amount of current to a reasonable value, say less than 500 mA. The battery can tolerate up to about 1.8 Amps of charging current but you should use something far more conservative than that for safety reasons. And you are only trying to put a small charge on the battery (not completely charge it) so you don't need to use the fastest possible charging rate anyway.
Something incredibly cheap would be a USB cable (with the micro-B connector cut off) and a 1/4 watt, 100 ohm resistor connected to the positive supply line coming from a 5 volt USB wall wart charger. Even if the battery was a dead short, only 50 mA of current would flow and the resistor wouldn't burn up. If the battery was good but heavily discharged, you'd only be charging at a 20 mA rate - that would put a 10% charge on the battery in ~30 hours.
If you initially measured the battery and found it had a voltage of 2.5v or higher, you could use a 22 ohm, 1/4 watt resistor safely and charge the battery 10% in only 8 hours or so.
You can charge faster by using a resistor of a higher wattage rating, but 1/4 watt size are readily available and cheap.
The equation for power dissipated in the resistor is
P > V^2/R or
R > V^2/P = (Vs- Vb)^2/P
So for example in our case with Vs = 5, Vb = 3 and a 1/4 Watt (P) resistor, we would get
R > V^2/P = (Vs- Vb)^2/P = (5-3)^2/0.25 = 16 ohms.
The "dead shorted battery" worst case would be Vb=0 or
R > (5-0)^2/0.25 = 100 ohms
(so you can see where the numbers came from)
Anyway, that's my recommendation
- disassemble to the point of exposing the battery connector
-disconnect battery from tablet
- put battery on simple & safe charging circuit (+ terminal to resistor to + terminal, and - terminal to - terminal)
- let it sit for a while*
- reconnect to tablet and finish charging
- profit
* if you leave a live circuit unattended, even if it is only a 5v circuit, please please no exposed wiring or loose connections. Use tape and plastic straws for temporary insulation... or shrink wrap if you prefer a neater look.
Click to expand...
Click to collapse
Wow! THANK YOU VERY MUCH !! I did not expect such a detailed answer.
I REALLY appreciate for taking the time to answer me!
I will try the things you recommended:good::good::good:

rainfactor said:
Wow! THANK YOU VERY MUCH !! I did not expect such a detailed answer.
I REALLY appreciate for taking the time to answer me!
I will try the things you recommended:good::good::good:
Click to expand...
Click to collapse
The more information you can collect before you begin the more confidence you will have. Hopefully you have a voltmeter or can borrow one to insure you are getting the wiring polarity correct and you are not going to damage anything or cause a fire.
If the battery voltage is closer to 4v when you first crack open the device, then this hypothesis about an overly-discharged battery is not correct, and you should assume that some other mechanism is involved.
The resistor values I used as examples are just barely big enough to meet their own thermal rating (1/4 watt in the examples), so that means that they can get hot. I'm pretty sure their thermal rating is for "natural convection", meaning that you don't need to put a fan on them to keep them cool, but you shouldn't cover their bodies up with any insulation or shrink-wrap. Nor should you leave them in that state next to a pile of papers or a jug of gasoline
A more sophisticated approach would involve using an adjustable battery charger that operates near 5v (the normal wall-wart USB voltage) and will let you set the current level, but almost nobody owns one of those. (But I have plenty of dodgy USB cables that the cats have chewed on that can be sacrificed for a quick-n-dirty trickle charge exercise.)
good luck.

Has anyone tried connecting 5 Volts directly to the internal battery terminals ?

Does it damage the Board or not?
I accidentally did connect 5v for a second or so,
it did power on, i disconnected immediately, and after that it didnt power on for several hours,
but not sure if it was because of the interruption during boot, or overvoltage.
Can somebody confirm?
(i cant use a diode for voltage reduction, its a bit complicated, i use a load sharing capable solar charger board etc)

its a nook simple touch

Yow, don't do that!
Ok, it should be able to take it, but still.
I've often fed 4V to devices which had their battery blow up.
In worst cases I've used a diode for drop, but the voltage can be pretty variable over load.
The uboot on most things will not continue if there is zero voltage on the battery.
Also, the peak current of a device can go up to 600 mA or more at times.
That kind of current often can't come in through the USB connector.
Finally, battery packs have ID connections and thermistor.
Entirely disconnecting a battery pack will often prevent booting even when voltage is present.
If you have a dead battery pack always keep the the connector, cable and tiny PCB inside.
Attach a power supply to where the naked cells used to connect to the PCB.
For wiring of the battery pack see: https://forum.xda-developers.com/showpost.php?p=42552349&postcount=5

thanks, 2 weeks ago i prepared to measure possible resistors but did a google search before, found your description...
i use the protection board with a 18650 3000mAh lithium manganese (to prevent blow (up)) etc cell and charge it externally,
which requires switching between charging the batt + powering the nook over the batt terminals,
and using the batt for powering the nook , all that while the usb keyboard is connected and in use,
this is done via relay and a really big capacitor, which works great but is a bit ghettostyle.
i tried to use another charger board with load sharing circuitry instead,
but the only easy available module requires 5v minimum input, passes this 5v to load if the ac adapter is plugged in,
if not, it passes the battery voltage to load,
so a diode(+ parallel resistor to maintain voltage drop) or LDO doesnt work because it would at least steal around 0,5 v,
which is to much reduction for the battery voltage, because the nst powers off at ~ 3,7v,
easiest would be to just let the 5v to the nook but seems no good idea.
anyways, it works with the relay