Database Develop

[Q] difference between usb power and normal power supply

Hi!
I am building a special car charger for my galaxy s.
I put the 5V to MicroUSB VCC and also GND...
The phone is charging.
Here the problem:
I'm using tasker app to detect many phone states and automatically switch some features when pluging in some devices. I noticed that the normal galaxy s charger is detected as normal power supply. My method with just VCC=5V makes the phone think that there is a usb cable on it. So it says: Charging with USB power.
I started thinking about how the normal power supply tells the phone that it is no USB. First I thought of the 5th pin (pin 4: ID) on the micro USB connector. Later I noticed that it seems that the normal charger does not has this pin. So it should be open circuit like I have on my charger...
Does anybody know what the normal charger does to tell the phone it is a normal charger?
Additional story:
I found another usb device with micro usb which is charging with the normal charger only! With normal usb cable it is not possible to charge it. Right now I can't charge this device with my car adaptor.

What sets the charging type is the resistance between the data pins. USB charging will be limited to about 500mA, a plain charger can deliver more current, thus reducing charge time. Somewhere on XDA resistor values are listed for various modes but this site has a really bad search engine.

rogem_kk said:
... but this site has a really bad search engine.
Click to expand...
Click to collapse
you are right!
normally nobody dares to say something bad about this site. Don't get me wrong... The information and the community is awesome but the search engine is awful.

But google works still OK
Refer to the thread: Click and look for post 60 to start from there are some interesting conclusions, e.g. in post 71 as well...

Charging and chargers

Hey, after some time with my D4 I decided to sum up and ask about my charging problems
The first issue I ran into was unresponsive/randomly misbehaving touchscreeen after plugging into generic USB charger through my data cable. I blame the charger's voltage - I measured 5.45V on it, it was supposed to be 5V/1A... It was just a $3 charger though so no big deal. It works fine with OEM Sony Ericsson charger giving out 4.95V and (per sticker) 750mA.
What I found out later is that it does not charge from a laptop that is off but with USB powered (Lenovo R500). I double checked it gives the juice out by charging my BT hands-free. I guess it measures the current (as standard USB gives out 500mA) and tests the data connection for low currents. It still charges pretty slow from the computer though. I can have the computer turned on, but my old solar charger with battery has the same issue which is really inconvenient :-/
I would greatly welcome any tested mod to the cable, maybe soldering pins 4 and 5 on the micro USB end, as it worked for my old E-TEN X800?

For the voltage issue:
How did you measure the 5.45V? With nothing connected?
Those low-quality power adaptor does not have good voltage regulators, and the voltage will drop when you are charging. Therefore the zero loading voltage is slightly higher.
For the charging issue, it's nothing related to your notebook, but Android itself.
When android detected it is a USB connection, it limits the charging current to avoid damage of the USB port of the computer. If you solder a USB cable with only power pins connected but not data pins, you will get much faster charging rate.
Moreover, AOKP ROM have a "Fast Charge" option (Settings --> ROM Control --> Performance --> "Other Settings" Page), which simply disable USB functionality to force the phone charges as using a power adaptor

KinChungE said:
For the voltage issue:
How did you measure the 5.45V? With nothing connected?
Those low-quality power adaptor does not have good voltage regulators, and the voltage will drop when you are charging. Therefore the zero loading voltage is slightly higher.
For the charging issue, it's nothing related to your notebook, but Android itself.
When android detected it is a USB connection, it limits the charging current to avoid damage of the USB port of the computer. If you solder a USB cable with only power pins connected but not data pins, you will get much faster charging rate.
Moreover, AOKP ROM have a "Fast Charge" option (Settings --> ROM Control --> Performance --> "Other Settings" Page), which simply disable USB functionality to force the phone charges as using a power adaptor
Click to expand...
Click to collapse
I've tried a couple of the "power only" USB cables that presumably don't have the data pins connected, but my Droid 4 fails to recognise when they are connected (even if you try it with a power supply, rather than a computer's USB port). I'm not sure whether one of the data pins needs to be connected to ground or something to make it realise it's connected?
Cheers,
Steve.

Back powered hub

I am trying to modify a powered hub so that i can charge the nook and power accessories at the same time. There is a picture below with the information i have found out so far. I can see the diode that i am supposed to bypass, and once a jump it as seen in the picture i can charge the nook, but it will then not connect to any devices even when in usb host. Bother usb host and vbus will be selected but if i have the barrel plug connected then any device i have connected to the nook disconnects. Just fyi, the wire connected to the spot where it goes to the 5v on the usb plug, goes nowhere. Its only there for testing purposes.

Tasker help - simulating usb unplug/plug

I have a phone which I want permanently connected to an OTG keyboard and charger. (Mounted in car)
It's connected via a microUSB charging hub. (Pic attached)
The male MicroUSB must be plugged into the phone at all times - it cannot be removed. Likewise, all other components (OTG keyboard and microUSB power cord) must always be connected permanently.
So, the only option I have is to switch the power off at the source, i.e. cut power to the microUSB charging cable going into the whole system. (The power is cut when the car is turned off)
All the OTG charging hubs do not resume charging when the power supply is turned on again. It only recognises to charge the phone when I unplug the male MicroUSB from the phone and reinsert it.
Can I set up a tasker task to simulate this unplugging and plugging, say when the battery is less than 50% - so that when the car is on it charges the phone.
I've done some research and there seems to be a usb bind/unbind command I could potentially use?
Thanks for the help.

brownah92 said:
I have a phone which I want permanently connected to an OTG keyboard and charger. (Mounted in car)
It's connected via a microUSB charging hub. (Pic attached)
The male MicroUSB must be plugged into the phone at all times - it cannot be removed. Likewise, all other components (OTG keyboard and microUSB power cord) must always be connected permanently.
So, the only option I have is to switch the power off at the source, i.e. cut power to the microUSB charging cable going into the whole system. (The power is cut when the car is turned off)
All the OTG charging hubs do not resume charging when the power supply is turned on again. It only recognises to charge the phone when I unplug the male MicroUSB from the phone and reinsert it.
Can I set up a tasker task to simulate this unplugging and plugging, say when the battery is less than 50% - so that when the car is on it charges the phone.
I've done some research and there seems to be a usb bind/unbind command I could potentially use?
Thanks for the help.
Click to expand...
Click to collapse
You can cut 5v wire (to phone and not to hub-> needs 5v to operate with all usb devices) and put switch on, so when you need to charge just turn on the switch. So you have modified cable from hub to phone. Really simple solution. I've done it couple of times to fix friends tablets (aka 10 inch nav displays) + Phone charging + Auto android HUR + USB drive(for music collection), all shares same active powered hub.
Good luck.

Question charging the phone

Hello guys
I recently changed from S9+ to S21 and I have a question : I usually use my desktop computer to charge my phone during night while I sleep. (with data USB cable)
I have no problem when the desktop is on (under windows) : my phone charge (with USB cable) and I can transfert photos.
When my computer is off, when I plug the phone, the screen show the charging screen for 2 seconds and stops
I have no problem with my S9 to charge when the computer is off. (I know that there is an option in the bios to keep USB charging when computer is switched off)
It looks like the USB power is too low, and the S21 doesn't want to charge with it.
Maybe ther is an option in the phone to authorize this kind of charging ?

yan74s said:
Hello guys
I recently changed from S9+ to S21 and I have a question : I usually use my desktop computer to charge my phone during night while I sleep. (with data USB cable)
I have no problem when the desktop is on (under windows) : my phone charge (with USB cable) and I can transfert photos.
When my computer is off, when I plug the phone, the screen show the charging screen for 2 seconds and stops
I have no problem with my S9 to charge when the computer is off. (I know that there is an option in the bios to keep USB charging when computer is switched off)
It looks like the USB power is too low, and the S21 doesn't want to charge with it.
Maybe ther is an option in the phone to authorize this kind of charging ?
Click to expand...
Click to collapse
There isn't such an option in the OS as of now. It's possible that the S21 battery amp requirements are more than those of S9

Do you think the computer's USB port has a lower supply when the computer is turned off ?

We don't know what kind of computer you have, or what it's USB port capabilities are. That's something you can try to figure out, looking at your computer or manual for the computer's motherboard. Also check the BIOS settings, sometimes you can control the power state of the computer when it is "off" and whether power is still supplied to the USB ports (e.g., to allow the computer to boot up when it detects mouse or keyboard USB inputs).
As an example, my MSI motherboard has a feature where you can install software to set the USB ports to a high power output state, so you can power USB devices using more than the standard output current.
My Dell laptop has a USB port with a special symbol that means it's for high-power output for charging phones etc. So it can handle charging modern phones, and puts out more than 0.5 amps, but only for those USB ports with the special symbol (lightning bolt).
You'll need to just find out more information about what your computer is capable of.

I have a MSI gaming pro carbon X370 ( the optional wake by USB is on, without that, you're right, the USB are totally off and nothing will charge)
I did more investigations .... I tried all my USB cables and all USB ports and finally find 1 combination that works.
Only 1 of 12 USB cables worked ( the one took from an external HDD ) even the original cable supplied with the phone didn't work and nor a 100W Ugreen cable...
And only the front USB work. The different USB directly on the motherboard doesn't work with this phone, despite I always used them to charge many devices...
for information the working cable is a KAIBAO revision 3.0
Finally it doesn't work with this cable : it take longer before the phone stops to charge, but it stops too ...

Hi,
You need to check the power requirements of your new phone.
Thank you.