Related
Problem:
The X will not charge!
Situations:
1) My xbox 360 is plugged in, but off. The Droid X will not charge. Turn on the xbox & the X starts to charge. Turn off the xbox and the X continues to charge...
2) My computer is plugged in, but off. Plug the Droid X in and it will not charge. Turn the computer on, the X starts charging. Turning the computer back off, the X continues to charge...
Idea:
A powered usb port is not enough to charge the X and changing usb modes does nothing. It needs some sort of usb acknowledgment from a computer to start the charging. Thinking about some sort of Force Charge app, though I don't know where to start...
um......are you saying that when you plug your X into a usb port on your Computer or your Xbox, it won't charge when the Devices are turned off?
I don't know of any device that supplies power to a usb port when its off, i.e. power off means usb port off too....
Maybe I'm mising something, but if you were to plug anything like an external hardrive, into your devices they shouldn't recieve power while the device is off.
wesscoggin said:
um......are you saying that when you plug your X into a usb port on your Computer or your Xbox, it won't charge when the Devices are turned off?
I don't know of any device that supplies power to a usb port when its off, i.e. power off means usb port off too....
Maybe I'm mising something, but if you were to plug anything like an external hardrive, into your devices they shouldn't recieve power while the device is off.
Click to expand...
Click to collapse
Plenty of device supply power to ports when they are off. How else are you supposed to use the BIOS features that allow a computer to be turned on using a KB or mouse? Do a Google search for "PC off USB on" you'll find plenty of posts about people complaining there devices stay powered on when they turn there PC off.
Ok, maybe I can explain this a little better....
The xbox 360:
When the device is "off", yet still plugged in, it still draws some power (what they call it phantom power). The usb ports still have power to them, and other parts, such as the wireless radio receiver is still powered, so you can turn it "on" with a wireless controller.
Now if one plugs a Droid X into the 360 in its "off" state, the phone will not charge. Turn the xbox "on", meaning you can play games (or go to the xbox dashboard) and the phone starts to charge. Keeping the phone plugged in and turning the xbox "off", the phone continues to charge. This means that something must initiate a charge and just having a powered usb port, is not enough.
Why the stock charger works, I do not know? It certainly doesn't have a computer in it...
PC:
My pc does the same thing: if the computer is "off" (meaning the motherboard still has power), then the phone will not charge. Turning the pc "on" (which eventually starts windows) is enough to charge the phone. Specifically the phone starts charging as soon as the bios says something along the lines of: initiating usb connections. Then turning the computer back "off", the phone still charges...
Well, I guess that is a cool feature on some devices that I had never heard about.
Forgive my ignorance.
First of all, as techy as I am, I don't claim to know everything about computers; however, the only time I've ever seen a computer able to turn on from the keyboard is if it's hibernating or in standby, never off completely. I built dozens of my own machines and support hundreds within a business environment and have yet to see such a feature built in.
If this is in fact what you are referring to, then the usb power on the ports during this mode is in a low power state (on most machines). These days, some modern boards are now coming with the ability to have full usb power to charge devices while the machine is in standby/hibernate/off.
I just built a machine using a gigabyte board that just came out with this feature in April of this year (http://www.gigabyte.com/microsite/185/on-off-charge.htm), so if you don't have this feature (or similar), it probably won't charge when the machine is off.
SiXiam said:
Ok, maybe I can explain this a little better....
The xbox 360:
When the device is "off", yet still plugged in, it still draws some power (what they call it phantom power). The usb ports still have power to them, and other parts, such as the wireless radio receiver is still powered, so you can turn it "on" with a wireless controller.
Now if one plugs a Droid X into the 360 in its "off" state, the phone will not charge. Turn the xbox "on", meaning you can play games (or go to the xbox dashboard) and the phone starts to charge. Keeping the phone plugged in and turning the xbox "off", the phone continues to charge. This means that something must initiate a charge and just having a powered usb port, is not enough.
Why the stock charger works, I do not know? It certainly doesn't have a computer in it...
PC:
My pc does the same thing: if the computer is "off" (meaning the motherboard still has power), then the phone will not charge. Turning the pc "on" (which eventually starts windows) is enough to charge the phone. Specifically the phone starts charging as soon as the bios says something along the lines of: initiating usb connections. Then turning the computer back "off", the phone still charges...
Click to expand...
Click to collapse
I think you need to check the usb ports on the Xbox with a voltmeter to see if there is 5V there when the xbox is "off". Do the same with your PC. I personally dont think there's output voltage on the usb ports when those devices are off. At least I know the PS3 usb ports are definitely not putting out 5V when its off, same with my PC that has a ASUS mobo.
Some newer motherboards support this feature, as dvation191 pointed out about the Gigabyte board. But even they mention, depending on the device, the system might have to be on first. I'm sure things will get better in the near future too, as in become a part of the standard.
HostileJava said:
Plenty of device supply power to ports when they are off. How else are you supposed to use the BIOS features that allow a computer to be turned on using a KB or mouse?
Click to expand...
Click to collapse
It's the other way around, the port is supplying the power to the device.
When a computer is off, the motherboard still has power, and it basically recognizes that something is plugged in to the port. But it doesn't always mean that there is enough power fed to the USB port to charge a device.
To turn the system on with k/b or mouse, it's basically just looking for a signal that only requires use of minimum voltage, which is being fed to the k/b or mouse from the USB port, it recognizes a specific interruption and system powers on.
This feature has existed even before USB.
Like derek4484 said, checking the USB port with a voltmeter is the way to find out if your not sure if your PC or console supports full USB power when system is in the off state.
The Omnia was like this. If you look at the USB cable where it plugs into the droid x, I will bet it will have different pins than the wall wart...
Maybe you guys are just not understanding what I'm saying, or I am very bad at explaining it.
The ports on my xbox and my pc have enough power to charge the Droid X, even in an "off" state. I don't need a voltmeter because I know it charges the phone. What is wrong is it won't initialize a charge when the device is off. Meaning the device has to be "on" for it to start charging. Then you can turn it "off" and it will continue to charge. Something in the Droid X is not allowing it to charge, without some sort of initializing.
Hi everyone!
Firstly I am not sure if this is correct forum, but its only one related with hardware...
I has built my own emergency charger powered with solar energy.
It can provide 5V with 2A max. (about 10W) and provides two USB ports for devices.
Althought I dont have any phone/tablet with USB OTG (Host) function, I d like to prepare it to provide all this functions:
- charge two client devices
- charge two host devices
- charge one host and one client device
But, there is one problem with power - some OTG devices provides power, and some not.
Thats the thing, why I am asking - if both chargers connectors are powered and one host device is connected in it there will be a power collision - on one wire will be 5V from both sides - from e.g. phone and from charger. This will surely damage the phone because of shortcut.
I am right? Or, is a hosts power enabled, only, if there is not any external power plugged?
Hope, that anyone will understand, I can also provide a schematics later it it could help
Thanks anyone !!!
The wire is the same, so there won't be any collision, it doesn't matter where the voltage source point is when it's applied on the same wire (without any component in between the voltage sources).
I guess maybe the only thing will happen is that the phone battery won't have much or perhaps even no drain?
And speculating here on same line of thought, dunno exactly how the charging circuits work on the phone, but i guess it won't charge when in OTG mode even with an external power power source available...
My Touchpad doesn't provide OTG power but refuses to charge when in OTG mode, maybe other devices are different though. OTG will still work on it even if I disconnect the +5v Vcc (red) wire. If you wanted to force USB devices to be powered from the external supply maybe you could try disconnecting Vcc from the device.
Thanks - more people, more ideas,more knowledge
As told - there are two kinds of OTG devices - self powered (few Xperia`s and Samsung devices) and non powered (spunkler88`s Touchpad and e.g. my Xperia X10i).
In case of non powered devices, there shouldn`t be any problem, think that host just won`t accept power and nothing bad happens. But in case ot self.powered devices there is in OTG mode voltage on vcc pin - 3,3 or 5V (low power or high power mode).
I`m not so demanding to want host and slave to be charged at the same time.
We dont have to worry about non powered host devices, but afraid about powered ones... Or even if we don`t know, if our device is powered or not
Elusivo:
I know, that it is the same wire You maybe didn`t caught my point - there could be two power sources on one wire - one could be phone (in OTG mode) and one power on hub.
Will post an scheme as soon as possible.
HeliumX10 said:
I know, that it is the same wire You maybe didn`t caught my point - there could be two power sources on one wire - one could be phone (in OTG mode) and one power on hub.
Will post an scheme as soon as possible.
Click to expand...
Click to collapse
Yes, actually there shouldn't be any issues with this now that I think of it. The phone if providing powered USB OTG would simply act as a parallel voltage source with the charger meaning voltage stays the same and the available currents add.
So, there is the block diagram of device which i have built:
The red cross indicates the one wire collision when DEVICE B provides power. If device B doesn`t provide power there won`t be any problems surely.
But as I thought of it, there is no solution for it - parallel voltage will surely damage one device on one side. The power sources providing high-efficient PWM power has very very low input resistance. So if we connect any voltage to its output, very high current will flow throught and surely damage the power source. This can happen very easily, because from phycisict`s point of view the higher voltage source will damage the less voltage source (there is +/- 10% tolerance on USB power, so this could happen everytime).
So now I am thinking about some mosfet auto switching circuit, which could automatically connect or disconnect power from master device... Or maybe will simple add an switch which will disconnect the power from master device everytime and power just a slave.
< wrong posting removed >
It doesn't pay to overthink this.
These devices are usually designed to take a beating.
Just connect all the Vcc's together.
I've been using something similar on my B&N Nook Touch for months.
It's not a solar charger, but a modified $10 USB hub.
I can use USB host mode on my Nook and charge at the same time.
Of course, all the peripherals are powered off the hub power supply too.
A general schematic is attached, pull the diode and insert a jumper.
Since USB was really not designed to charge in host mode,
there are two problems related to getting the device charging circuit to play nicely.
When using host mode to directly power a peripheral you must make the device charging circuit go off.
To go into host mode the device must raise the Vcc line to 90% of 5V, i.e. >4.5V.
If the device charging circuit is still enabled it will try to charge itself using itself!
When using host mode with incoming power the device charging circuit must be convinced to charge.
Renate NST said:
It doesn't pay to overthink this.
These devices are usually designed to take a beating.
Click to expand...
Click to collapse
Yeah, mostly yes, but dont want to try if this is also for all devices. Most of them could take beatings,some not... So trying to design absolute save solution
Renate NST said:
A general schematic is attached, pull the diode and insert a jumper.
Click to expand...
Click to collapse
See that, diode is used as blocking diode, which prevents shortcut So VCCs cant be connected together without protection. It seems that is for case I spoke about power provided from OTG device....
So as I see, simpliest solution will be the best. I will add a switch at the output for one USB ports VCC wire. And if I will use my charger as host active hub, will disconnect power (with switch) to one port, second port will be powered all the time. When charging two slave devices, i could switch power back too to the second USB port.
Renate NST said:
When using host mode to directly power a peripheral you must make the device charging circuit go off.
To go into host mode the device must raise the Vcc line to 90% of 5V, i.e. >4.5V.
Click to expand...
Click to collapse
OK, mainly thankx for this lines, once it happened that my phone indicated, thats chagring, but battery ran down.... Thought that was some kind of software relaed thing....
Hi Renate,
I've read and re-read your points several times and I think I understand.
My goal is to put together a battery powered USB Hub that also charges the phone at the same time. From your points, the B&N Nook is capable of going into Host mode while still accepting a charge - do you believe this to be true of most/all devices?
Did you have to do anything to get the Nook to charge in host mode other than supplying power by putting a jumper in lieu of the diode?
What $10 powered USB hub did you use?
Sorry for all the questions.
Renate NST said:
It doesn't pay to overthink this.
These devices are usually designed to take a beating.
Just connect all the Vcc's together.
I've been using something similar on my B&N Nook Touch for months.
It's not a solar charger, but a modified $10 USB hub.
I can use USB host mode on my Nook and charge at the same time.
Of course, all the peripherals are powered off the hub power supply too.
A general schematic is attached, pull the diode and insert a jumper.
Since USB was really not designed to charge in host mode,
there are two problems related to getting the device charging circuit to play nicely.
When using host mode to directly power a peripheral you must make the device charging circuit go off.
To go into host mode the device must raise the Vcc line to 90% of 5V, i.e. >4.5V.
If the device charging circuit is still enabled it will try to charge itself using itself!
When using host mode with incoming power the device charging circuit must be convinced to charge.
Click to expand...
Click to collapse
zuberio said:
From your points, the B&N Nook is capable of going into Host mode while still accepting a charge - do you believe this to be true of most/all devices?
Click to expand...
Click to collapse
I will answer these lines
Nook can charge when in host mode. But some new devices form Sony and Samsung cant,because they are providing power to hosted device. And if you connect active hub to them in host mode, you will damage the phone - thats why I opened this topic, but I solved it with simple diode indicator and switch (manually disconnects power to the phone if it provides power itself).
zuberio said:
What $10 powered USB hub did you use?
Click to expand...
Click to collapse
I just meant any generic hub. They are all about the same.
Usually the input diode is easy to identify.
Often it's the physically largest device present.
If you want, post a good photo.
The 4 port ones have one chip, 2 for 7, 3 for 10, 4 for 13.
I've never seen/heard of a hub chip with more than four outputs.
Yes, the USB spec does say only four outputs, but that's for unpowered hubs.
The spec for all the device USB chips have a maximum recommended of 7V on the lines.
I don't lose any sleep putting my 5V in.
Thanks for warning me off just going out and applying Vcc to my phone in host mode without first testing if it supplies it's own power.
When you say diode indicator do you mean an LED? And if the LED lights up you flip a switch to disconnect the hub power to the phone?
HeliumX10 said:
I will answer these lines
Nook can charge when in host mode. But some new devices form Sony and Samsung cant,because they are providing power to hosted device. And if you connect active hub to them in host mode, you will damage the phone - thats why I opened this topic, but I solved it with simple diode indicator and switch (manually disconnects power to the phone if it provides power itself).
Click to expand...
Click to collapse
---------- Post added at 07:42 PM ---------- Previous post was at 07:31 PM ----------
Ah, I understand now.
I guess the safest option for my battery backup/powered usb hub device is to install a 'mode' switch. Either it's a battery backup, or it's a battery powered USB hub - depending on the 'mode'.
Now I just need to hunt down a cheap powered USB hub and a battery that will power it or my phone.......
Actually, would there be any issues using an inline powered USB hub and disconnecting the Vcc from the host side to instead attach to a 5V 1A power source? The power source could probably be two minty-boosts in parallel.
[EDIT] Doh, I looked again at your hub.jpg - I just need to use a powered USB hub setup like that with a switch to bypass the diode for the 'phone charge mode' mentioned above (probably with some special resistances between D+ and D- depending on the device).
Renate NST said:
I just meant any generic hub. They are all about the same.
Usually the input diode is easy to identify.
Often it's the physically largest device present.
If you want, post a good photo.
The 4 port ones have one chip, 2 for 7, 3 for 10, 4 for 14.
I've never seen/heard of a hub chip with more than four outputs.
Yes, the USB spec does say only four outputs, but that's for unpowered hubs.
The spec for all the device USB chips have a maximum recommended of 7V on the lines.
I don't lose any sleep putting my 5V in.
Click to expand...
Click to collapse
zuberio said:
(probably with some special resistances between D+ and D- depending on the device).
Click to expand...
Click to collapse
No, resistors between D+ and D- are only for charging devices that are not communicating.
If you want to charge and communicate then you have to leave those alone.
That's why I said that you may need a kernel driver mod or an app to turn on charging when communicating.
I agree and understand - I guess I wasn't very clear in my last post.
My device will have two separate modes.
Mode 1:
Battery powered USB hub that doesn't provide power upstream to the OTG host device.
Mode 2:
Battery backup power device - powered USB hub disconnected
Such a device would be compatible with all Android devices, regardless of weather they provide power in OTG Host mode or not
Renate NST said:
No, resistors between D+ and D- are only for charging devices that are not communicating.
If you want to charge and communicate then you have to leave those alone.
That's why I said that you may need a kernel driver mod or an app to turn on charging when communicating.
Click to expand...
Click to collapse
zuberio said:
I agree and understand - I guess I wasn't very clear in my last post.
My device will have two separate modes.
Mode 1:
Battery powered USB hub that doesn't provide power upstream to the OTG host device.
Mode 2:
Battery backup power device - powered USB hub disconnected
Such a device would be compatible with all Android devices, regardless of weather they provide power in OTG Host mode or not
Click to expand...
Click to collapse
I understood clearly
This is the exactly the same I made completely myself. It has only 2 ports (no active chip, simplier and more reliable solution). It has One connector only for OTG master and second one port is for host device. When switch is on, power is also delivered into OTG host port, otherwise poered are all of the slave ports. But mine is designed mainly as emergency charger (for OTG Master device or two slave only phones/devices), or as active hub (thats why I added the switch with resistor and diode as power check).
Will post a diagram if you want.
prie irgseha
My touchpad is not power OTG, but refuses to load when the OTG mode, other devices will be different. OTG still working on it, even if I disconnect Vcc +5 V (red) wire. If you force, the USB devices be powered by external power supply might try unplugging the device Vcc.
BC1.2 Usb battery charging specs
Hi All,
I see that the last post here is a month ago, but here goes anyway. I am looking to do the same thing - I want to hack a 4 port powered USB hub to also charge the host (upstream) device.
Two modes of operation shouldn't be required. The specs allow for the phone to act as the USB host, and simultaneously charge. A powered USB should be easy to hack to simultaneously charge the phone and give you a useable USB hub for keyboard/mouse/usb stick or high-powered devices you can't use directly on the phone like USB hard disks.
I've made a reasonably close study of the Battery Charging Specification rev 1.2 (dec 2010) (USB implementers forum). The relevant sections and diagrams are around section 6.3: Standard ACA (accessory charging adapter) which could be a modified 4-port powered USB hub, hacked to be an "Accessory Charger Adapter" (figure 6-1):
1. The charger port should be 5V; jump that to the 5V V+ pin on the "OTG Port" - the OTG port would be the USB upstream port on the hub.
2. An ID resistance needs to be fitted integral to the μ-A Plug connecting to the OTG device, 124kohm between the ID pin and GND. (ref table 5-3 Resistances: RID_A; table 6-2 row 6)
I won't be able to use it anywhere else, because of the short to the V+ pin I've put there, but I would then have a battery charger for my phone which simultaneously works as a 4 port hub.
I have a Galaxy Note N7000. Does anyone know if this is FULLY compliant with the above referenced BC1.2 spec? I wonder because the Note also does audio and HDMI out on that port. Presumably with non-standard Rid values at the connector end.
Different hardware supports different ID pin sensing and data pin multiplexing.
On the Nook Touch, which uses a TPS65291, ID sensing is just short/open.
There is ability to use UART through the ULPI interface, but I haven't noticed it.
Many devices have separate muxes to integrate MHL, UART, CarKit (audio) and USB.
The CarKit is the tricky one because the signal goes below ground.
scitobor said:
I have a Galaxy Note N7000. Does anyone know if this is FULLY compliant with the above referenced BC1.2 spec? I wonder because the Note also does audio and HDMI out on that port. Presumably with non-standard Rid values at the connector end.
Click to expand...
Click to collapse
I suspect that the N7000 is very similar in Specs to the I9100, and thus it is more likely that it conform to the BC1.1 as mentioned and linked in this thread/post here. Remember that HDMI (and possibly audio) is not covered by the BC specs and very manufacturer dependent.
I figured I would share this since I have not found another thread with this info.
The Galaxy Note 10.1 will charge from usb.
I find this interesting because no tablet, at least none I have known, will do this. They all need to be actually plugged into a wall outlet to charge. However, my note 10.1 has charged from around 13% to 32% plugged into USB. Now, mind you , it doesnt charge very fast, but it does charge.
For some this won't matter. In my case, that 3 ft cord doesnt go from the floor outlet to my desk at work too easily, but the usb will plug in very easily and reach where I need it too. At the very least, it will add a little more time to the length of the batter. I work a 10 hour shift, not adding in the hour for lunch, and I can usually made it about 8 hours. So this may get me the extra two hours I need...hopefully.
phoenixbennu said:
I figured I would share this since I have not found another thread with this info.
The Galaxy Note 10.1 will charge from usb.
I find this interesting because no tablet, at least none I have known, will do this. They all need to be actually plugged into a wall outlet to charge. However, my note 10.1 has charged from around 13% to 32% plugged into USB. Now, mind you , it doesnt charge very fast, but it does charge.
For some this won't matter. In my case, that 3 ft cord doesnt go from the floor outlet to my desk at work too easily, but the usb will plug in very easily and reach where I need it too. At the very least, it will add a little more time to the length of the batter. I work a 10 hour shift, not adding in the hour for lunch, and I can usually made it about 8 hours. So this may get me the extra two hours I need...hopefully.
Click to expand...
Click to collapse
Hmm, I think mine claims not to (it puts an X on the battery icon), but I didn't leave it plugged into my computer long enough to see whether it charged or not. I think all tablets can potentially charge via USB port on a PC, it's just that most disable it out of the box but eg. for the Galaxy Tab 10.1 custom kernels could enable charging over USB.
iofthestorm said:
Hmm, I think mine claims not to (it puts an X on the battery icon), but I didn't leave it plugged into my computer long enough to see whether it charged or not. I think all tablets can potentially charge via USB port on a PC, it's just that most disable it out of the box but eg. for the Galaxy Tab 10.1 custom kernels could enable charging over USB.
Click to expand...
Click to collapse
Mine also puts the RED X over the battery icon whether I try to charge it through a PC USB port or other USB charging port other than the Samsung adapter (Goal Zero 150 usb port and Panatech 10000mah external USB battery pack). The tablet shows that it is charging when i view it using GO POWER MASTER app. Watched it for 5 minutes but with WIFI off, it still dropped from 88% to 87%. I am however using the stock kernel.
It charges faster if you have the screen off. The usb gives more or less what you need to keep it running with the screen on.
Skickat från min GT-I9300 via Tapatalk 2
Mine put the red X on the battery icon as well, but still charged. I had to have the screen off.
I had mind plugged into my USB 3.0 port (which should really make a difference) to transfer some files, and then just left it plugged in and it charges. Its definitely a trickle charge, but I am glad to see it does this, as my a500 did not.
When I transferred 40Gb of data to the mSD via MTP (screen off) and called up the batt-graph after disconnection it showed me a fair charging rate. Not stunning but at least a noticeable charge ( from 63% to 82% in three hours).
So it does charge the battery, in spite of the red X?
Yes it does, albeit very slowly.
You guys are misinterpreting the red x. Just got off the phone with Samsung. The x stands for "extra awesome charging". I swear.
Sent from my GT-N8013 using Tapatalk 2
phoenixbennu said:
I figured I would share this since I have not found another thread with this info.
The Galaxy Note 10.1 will charge from usb.
I find this interesting because no tablet, at least none I have known, will do this. They all need to be actually plugged into a wall outlet to charge. However, my note 10.1 has charged from around 13% to 32% plugged into USB. Now, mind you , it doesnt charge very fast, but it does charge.
For some this won't matter. In my case, that 3 ft cord doesnt go from the floor outlet to my desk at work too easily, but the usb will plug in very easily and reach where I need it too. At the very least, it will add a little more time to the length of the batter. I work a 10 hour shift, not adding in the hour for lunch, and I can usually made it about 8 hours. So this may get me the extra two hours I need...hopefully.
Click to expand...
Click to collapse
Interesting, because every tablet I've owned (Tab 10.1 and Nexus 7) behaved like this.
They will charge VERY slowly on USB - and will likely not charge at all if the screen is on due to the total unit power consumption being >500 mA.
Entropy512 said:
Interesting, because every tablet I've owned (Tab 10.1 and Nexus 7) behaved like this.
They will charge VERY slowly on USB - and will likely not charge at all if the screen is on due to the total unit power consumption being >500 mA.
Click to expand...
Click to collapse
Same here. iPads, nook color, Samsung tablets, all say not charging but do trickle charge if you are doing anything to drain it faster than thenusb can supply. It takes around 8 to 10 hours to charge my gt101 through regular USB 2.0.
mitchellvii said:
You guys are misinterpreting the red x. Just got off the phone with Samsung. The x stands for "extra awesome charging". I swear.
Sent from my GT-N8013 using Tapatalk 2
Click to expand...
Click to collapse
Bwahahaha... A friend of mine posted on twitter that Apple should make something that lets iDevices charge each other... Ours actually can because of USB host! I actually lost the usb host adapter for my old galaxy tab so I need to get a new one but I had one for my gs3, and it does charge my tablet. But the reverse is clearly more useful.
Sent from my SCH-I535 using Tapatalk 2
Tested again when attached to Notebook by USB:
Screen on at max. Brightness and working: batt charge stays level
Screen off: batt charges approx. 5% per hour
Tested on GNote charger (1A output)
Screen on : charging very slowly (approx. 3% per hour)
Screen off: charging approx. 8% per hour
Tested on iPad charger:
Slower than original charger although max. Output:
The more items you have attacht to your computers USB the less power it has to allow your tablet to draw for charging.
donec said:
The more items you have attacht to your computers USB the less power it has to allow your tablet to draw for charging.
Click to expand...
Click to collapse
I don't think this is the case. The USB ports provide a set power output, and not variable by available power supply type of output.
phoenixbennu said:
I don't think this is the case. The USB ports provide a set power output, and not variable by available power supply type of output.
Click to expand...
Click to collapse
You are correct they are not variable but they only have a given amount ofpwer available and if you are drawing the max and add another device that needs more power to charge the power will not be available.
donec said:
You are correct they are not variable but they only have a given amount ofpwer available and if you are drawing the max and add another device that needs more power to charge the power will not be available.
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Click to collapse
Of course, everything has a limited power availability, USB ports being no exception, whether having their own psu or bus powered or whatever your setup may be, but unless you are doing something beyond practical use or have a poorly designed setup, than this should not be a problem. I know some systems out there, the mac book pro for example, specific limits USB power output between ports by design (you may even call it variable haha...but by design). However, in a general sense, you should not have a power output issue with simply plugging in for usb charging., even if all other ports are used up as well. So don't daisy chain, or do anything like that. Practical use should be fine. I personally hook my usb charged devices, like my phone, to my monitor at work. It was a few usb ports on the side, and it works great. Also, it keeps me from having to deal with all the annoying security popups that go with plugging it into the actual computer.
In a probably unfunny but still remotely amusing anecdote, I remember the massive work I put my a500 through. I used to have a usb hub attached with 2 1tb portable hard drives, a keyboard, a mouse, my phones, and more all charging directly from USB. Never had trouble with power issues, aside from quicker draining of the battery. lol.
does anyone know if charging is possible when you use an Y adapter on USB-OTG to hook up an external harddrive and a charger at the same time?
cproaudio said:
does anyone know if charging is possible when you use an Y adapter on USB-OTG to hook up an external harddrive and a charger at the same time?
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Barring any specific device hardware limitations, it is possible to do data transfer and power transfer at the same time using a y cable. Its essentially the same thing as using a usb hub, except you only have two ports instead of 4 or more.
As for actual practical use on the note, I have not tried it out, and I am not aware of any limitations built into software or hardware to prevent it. So, I do not see you having a problem with it.
Almost all tablets can charge through regular USB2 if they're sleeping (or better - powered off).
USB has power limits (USB1.1 is 100mA, USB2.0 is 500mA and USB3 is 2A) BUT these are the 'minimum maximums', if you will. That is, these are the current source *required* for certification. It's entirely permissable for a USB port to provide as much current as it wants - it just can't be limited to *less* than these amounts.
USB 2.0 and later ports are also supposed to implement 'overcurrent' warnings if the device is taking more current than the port can provide..
That's why, for example, some ports can drive a CDROM or external HD drive without a problem - while other ones can't.
The Note 10.1 needs a little over 2A @ 5V to charge at a reasonable rate.
One other note, if you let your battery drain very low, then the lower current of most USB 2 ports won't be enough to charge it even if it's off. The charge current curve isn't linear.
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?
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[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).
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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.
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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%
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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?
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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.
I need to have an MHL adapter connected to my Samsung Galaxy s4 i9506 which mirrors it's screen to a monitor/info screen indefinitely, but the problem is that an MHL adapter outputs a measly 300mA (Tried lots of chargers but the output never changed) which is nowhere enough. I did some research and found out that I can up that number by installing a custom ROM that enables fast charging so tried that with my other phones doing the same task that are i9505 and SGH-M919. I managed to install a custom ROM that enabled fast charge through STweaks which upped the output all the way to 1000mA, but I haven't been able to find out a ROM that enables the feature for i9506. I tried LineageOS 14.1 which should have fast charge enabled by default, but when I used Ampere to check the charging current the output was 300mA, so I assume that fast charge didn't get enabled.
Does anybody know a ROM, that enables fast charge for i9506, or how I could scrape by with that measly 300mA when the only thing the phone needs to do is to mirror a web page to a monitor. Chrome cast isn't an option, because if the connection drops you need to manually connect it again, and since the phones should be operational for months without rebooting the connection is bound to drop sooner or later.
That's a kernel thing. So, unless you find a kernel for the I9506 that supports 1000 mAh USB charging, you're out of luck in this regard.
I guess the only way to survive with 300 mAh would be to turn the screen off, otherwise the phone will use more power than it receives.
Another solution would be wireless charging. I think this is your best bet.
Is there an app that I could use that timers off the screen during the night and then wakes it in the morning? There are a lot of apps that let you time music and other apps, and even turn off the screen, but I haven't found one yet that could also wake the phone up later.
nyoatype said:
Is there an app that I could use that timers off the screen during the night and then wakes it in the morning? There are a lot of apps that let you time music and other apps, and even turn off the screen, but I haven't found one yet that could also wake the phone up later.
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Maybe Tasker.
@nyoatype
I'm searching for same as you.
Having mhl adapter (which is original as i think, working without power source and resolution is 1080p60). After connecting to AC 1.2A max charging power for phone (I9505) is only 300mAh, on original Samsung charger 2.1A is little bit more - 400mAh but obviously it's still not enough for me. Power output doesn't change even after enabling USB fast charging (700mAh or 1000mAh, doesn't matter).
I was looking to kernel source https://github.com/Slim80/Imperium_...ter/arch/arm/mach-msm/board-fusion3-battery.c
where are defined values of charging for MHL 500/MHL 900/MHL 1500 (phone probably can detect which one is plugged) but after increase charge_current_max and charge_current for every MHL type I do not see any difference unfortunately, so I'm searching still what's is going on and where i can increase power output from MHL to phone.
I'm searching for a way to change resolution of MHL video output too, so if anyone kernel master can follow me a little bit, will be great (maybe here https://github.com/Slim80/Imperium_Kernel_TW_5.0.1/blob/master/drivers/video/msm/external_common.c in line 40 -
HTML:
int hdmi_forced_resolution = - 1 ;
)
PolishVodka said:
@nyoatype
I'm searching for same as you.
Having mhl adapter (which is original as i think, working without power source and resolution is 1080p60). After connecting to AC 1.2A max charging power for phone (I9505) is only 300mAh, on original Samsung charger 2.1A is little bit more - 400mAh but obviously it's still not enough for me. Power output doesn't change even after enabling USB fast charging (700mAh or 1000mAh, doesn't matter).
I was looking to kernel source https://github.com/Slim80/Imperium_...ter/arch/arm/mach-msm/board-fusion3-battery.c
where are defined values of charging for MHL 500/MHL 900/MHL 1500 (phone probably can detect which one is plugged) but after increase charge_current_max and charge_current for every MHL type I do not see any difference unfortunately, so I'm searching still what's is going on and where i can increase power output from MHL to phone.
I'm searching for a way to change resolution of MHL video output too, so if anyone kernel master can follow me a little bit, will be great (maybe here https://github.com/Slim80/Imperium_Kernel_TW_5.0.1/blob/master/drivers/video/msm/external_common.c in line 40 -
HTML:
int hdmi_forced_resolution = - 1 ;
)
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I used this ROM to up up my numbers with i9505 to 500mAh-640mAh depending on charger and mhl adapter, so if it's of any help to you you can try it. Let me know if you find anything that could be of use : D https://forum.xda-developers.com/ga...dcteam-android-source-project-mra58v-t3251663
Is there any way to wake phone up with a timer? For example make the phone wake up every morning at 8 o'clock? I'm using automate to put the phone to sleep at a fixed time, but waking it up doesn't seem to be as easy (The timer block in automate actually has a checkbox with description "Awake device", but it doesn't actually wake the phone up).
nyoatype said:
Is there any way to wake phone up with a timer? For example make the phone wake up every morning at 8 o'clock? I'm using automate to put the phone to sleep at a fixed time, but waking it up doesn't seem to be as easy (The timer block in automate actually has a checkbox with description "Awake device", but it doesn't actually wake the phone up).
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I already told you to try Tasker. Did you do it?
Pwnycorn said:
I already told you to try Tasker. Did you do it?
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I haven't yet added a payment option to Google store (Since this is work related and I'd need to use the companys payment information) so haven't been able to try Tasker. I'll try it when I'm able to get my boss' approval.
I'm also trying to do some physical changes to one of the MHL adapters to bypass it, so that the current would come straight from the charger. This means I'll cut the Power and GND (red and black wires) of the microUSB cable connected to the phone and connect them in parallel with the red and black cables going to the MHL adapter. I'm not sure, but this might cause the MHL adapter get power from the charger, but instead of supplying the power to the phone, the phone would get it's power straight from the charger (although it would still be USB-charging since the data pins are being used, but that wouldn't matter since I usually get 1000mAh when USB charging with computer).
Another possible solution is to use wireless charging pad, because I read that if the USB-connection uses MTP or PTP the wireless charging will take priority, so the data would go through the USB but the power would come from the wireless charger. I'm not sure about this because I read it from another forum post, so if somebody could confirm/deny it I would be seriously grateful!
Thanks for your replies and suggestions so far! This is one heck of a situation I've been put into so I really appreciate the help!