So I built a USB OTG adapter by shorting the ID pin to ground on the USB connector. This makes the Note go into host mode and start providing power out so it can talk to memory sticks and mice and keyboards.
Can I somehow through hardware or a custom kernel charge the note while in Host mode?
I want to build a little custom circuit for my Note that lets me charge it while in my car cradle but still talk to various USB devices like my OBDII adapter.
Yeah, nerdier than most Q&A, I'll try the development section if I do not get an answer.
David
I'm modifying an HP Ipaq keyboard from its ipaq interface to micro USB for my Note. I'm planning also putting in a powerpack and tiny powered USB hub to make the power connection.
If you got a small USB hub and gutted it then would that help?
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I'm not sure if it will work but I plan to find out once the ebay sourced parts arrive
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PurpleMelbourne said:
I'm not sure if it will work but I plan to find out once the ebay sourced parts arrive
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Click to expand...
Click to collapse
Dude, there is a small (but non-zero) chance you could permanently screw up your note doing what you describe (which is why I am asking the question instead of just hooking up a power supply and seeing what happens.
Most likely, nothing bad will happen but it won't work. You'll have two voltage sources fighting each other trying to push current in opposite directions but the relative difference in voltage will make for very small currents.
Worst case is you will fry something in your USB OTG chipset by shoving current into a system designed to push current out.
Second worst case is your battery pack goes boom because the Note is pushing current in to a regulator trying to push it out (unlikely).
David
So... PurpleMelbourne, what happened?
He killed his Note
Sent from my superior GT-N7000 using Tapatalk
Bump, I am still very much interested in this. Any help appreciated.
Related
Where is this at for the tab. Has anyone found it yet. I dont know if maybe froyo does not support the usb host mode needed or what. I saw that it was comming and yet cannot seem to find it. It was supposed to plug into the data port on the tab and give you the ability to attatch regular usb peripherals.
Any info is greatly appreciated
Sent from my SCH-I800 using Tapatalk
FWIW I saw a USB dock at Home Plus (Tesco for you guys in the UK) the other day for 29,000 KRW. Although I can't be sure, it appeared to be just a USB only dock but it looked like the HDMI dock recently reviewed on here.
Sent from my SHW-M180S using XDA App
I havnt seen it yet!
Sent from my GT-P1000 using XDA App
you should try out the Elan Mobidapter, it's a micro SD to USB adapter with integrated USB Host. i'm using the Mobidapter often and im happy with it, but you can only use USB Storages with it. No keyboard support.
BTW: Android itself doesn't have or support an USB Host.
3ph15t said:
BTW: Android itself doesn't have or support an USB Host.
Click to expand...
Click to collapse
That's not entirely true. Most android builds don't have the necessary usb host support as part of the kernel, but there's nothing to prevent someone from compiling it or adding it in as a module. The Tab is/was supposed to do this OOTB, and based on the pinout information posted elsewhere, there is at least kernel support for determining if host mode should be enabled. With a modified iPod connector from Sparkfun I was able to get the Tab's AccessoryManager process (I think that's what it was called) to see a non-supported device plugged in (externally-powered USB hard drive enclosure), even if it couldn't enumerate it. It could be because I didn't connect the requisite +5V for downstream devices, or because there is no usb_storage module available. More testing needs to be done on this before we write it off completely. Hopefully Samsung will just release their solution(s) sooner than later.
That is what I wish they would do. But im afraid with the tab10.1 it may be put on the back burner
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How did you modify the ipod connector? I have a few ipod/iphone cables lying around but they seem backwards compared to the sgt connector and difficult to modify.
I'm thinking about buying some sgt connectors or cables from china to play with.
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Unfortunately I could not find a supplier of the "mirrored" iPod connectors that the SGT uses. I contacted many China-based component mfgs and none could point me in the right direction for that stupid dock connector. So I got the iPod one from SparkFun, used an xacto knife and small file to grind off the material on either side of the connector that keys it into the mating iPod connector. This allows you to invert it and plug it into the SGT, which then gives you access to all 30 pins. The cheap charging/sync cables that you can get from ebay and the likes only come with 5-7 pins connected, and the rest missing.
3ph15t said:
you should try out the Elan Mobidapter, it's a micro SD to USB adapter with integrated USB Host. i'm using the Mobidapter often and im happy with it, but you can only use USB Storages with it. No keyboard support.
BTW: Android itself doesn't have or support an USB Host.
Click to expand...
Click to collapse
you know what sucks? I had a $100 haipad that had a microusb jack and came with a 6" adapter cable. guess what? you could plug in usb sticks, a usb mouse, or a usb keyboard. worked perfectly. mouse had a pointer, keyboard worked without a popup, it was all quite magical.
that was on a 2.1 resistive touchscreen chinese tablet.
why the hell can't the tab to this?
I have everything planed out for my tab install for my Dodge Magnum. But since the Nexus 7 doesnt have a sd slot I need to find a cable that can charge the tablet and use my flash drive at same time.
My flash drive(Usb on dash, so its easily removable)
http://www.amazon.com/gp/product/B00812F7O8/ref=ox_sc_act_title_4?ie=UTF8&smid=ATVPDKIKX0DER
Plugging this into the usb otg cable
http://www.amazon.com/Black-4-Port-...qid=1348442221&sr=8-3&keywords=4+port+usb+hub
I would love host cable with 2 usb inputs but cant seem to find it and dont know if its even possible.
Any help would be appreciated.
I found this on the bay : item # 140839631580 (Can't post link I'm too new... I was a lurker for a while -_-)
i didn't think the N7 could support power and OTG
You want it for video or audio? You could try a wifi solution for audio. Or be the guy that gets the pins to work.
there is NO data and charge at the same time. This is due to how the device switches from charge to usb mode thru the pin 4 . it senses rather a data cable or charge cable is being used . will not charge via otg..
there are several threads with experiments trying to get this work .You could use a wifi or bluethooth drive for data...
I have no clue what im doing but this is what im playing with at the moment. Its a old dock for sgs2 i believe but it has a dc and usb input on the back of it.
Im about to this because i have very little patience for china.
http://www.amazon.com/gp/product/B008CQKM2U/ref=ox_sc_act_title_1?ie=UTF8&smid=A24Y22QERZZ9SS
Would get the cheaper one but the juiced one has a flexible cable vs the fixed usb on the other one. Would this be pointless though?
Unfortunately OTG sends ground up the sense pin to trigger host mode. Once activated it sends 5V DOWN the USB cable to power your USB devices. Trying to send voltage up the cable at the same time to the Nexus would not be a good idea. The only way around it I can think of would be to hack the firmware to only activate the data pins in host mode and keep the power circuit seperate, then you could power the USB device from a modified dock/hub which sends power up the USB cable to the device.
A lot of work, and without the powered hub, OTG would be useless!
In the long run wouldn't it be easier to just plug in the power lead when needed and have the otg in the rest of the time? (or vice versa). It would mean you having to have easy access to the usb port but I can't see an easy non technical solution to connecting both at once.
Don't use the Nexus 7 for a car install. You can get an Acer Iconia A100 with a full-size USB port to connect to whatever external storage solution you want, and it's usually about the same price or cheaper than the Nexus 7.
earlyberd said:
Don't use the Nexus 7 for a car install. You can get an Acer Iconia A100 with a full-size USB port to connect to whatever external storage solution you want, and it's usually about the same price or cheaper than the Nexus 7.
Click to expand...
Click to collapse
Trying to sell tablet now. Going for galaxy tab 2
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Wouldn't this work?
http://tobuygoods.com/product_info.php?language=en¤cy=USD&products_id=131
I have galaxy tab 2 for sale. Pm me for details...
erica_renee said:
there is NO data and charge at the same time. This is due to how the device switches from charge to usb mode thru the pin 4 . it senses rather a data cable or charge cable is being used . will not charge via otg..
there are several threads with experiments trying to get this work .You could use a wifi or bluethooth drive for data...
Click to expand...
Click to collapse
Would it be possible to charge while using an OTG Cable for Keyboard/Mouse or does the same principle apply as inn data via OTG & charge?
Roland
Sent from my Nexus 7 using Tapatalk 2
Rolandh said:
Would it be possible to charge while using an OTG Cable for Keyboard/Mouse or does the same principle apply as inn data via OTG & charge?
Roland
Sent from my Nexus 7 using Tapatalk 2
Click to expand...
Click to collapse
Same principle. In normal OTG host mode the tablet powers the peripherals. A USB keyboard/mouse will be no exception to that.
intruda119 said:
I have no clue what im doing but this is what im playing with at the moment. Its a old dock for sgs2 i believe but it has a dc and usb input on the back of it.
Im about to this because i have very little patience for china.
http://www.amazon.com/gp/product/B008CQKM2U/ref=ox_sc_act_title_1?ie=UTF8&smid=A24Y22QERZZ9SS
Would get the cheaper one but the juiced one has a flexible cable vs the fixed usb on the other one. Would this be pointless though?
Click to expand...
Click to collapse
Sorry to resurrect an old thread but was wondering if you ever ended up getting that Juiced systems adapter and if it worked well with the N7. Been looking at it but haven't found any success stories on XDA with the N7, just the few Amazon reviews...
That cable would work but u need specific kernel tweaks for otg + charge to work. Pm me if anyone needs it.
Sent from my Nexus 7 using xda app-developers app
sadde said:
That cable would work but u need specific kernel tweaks for otg + charge to work. Pm me if anyone needs it.
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
Why PM you, why not just put it up here, Anyway here you guys go
http://forum.xda-developers.com/showthread.php?t=1835720
I am interested in this kernel patch quite a bit. I have a galaxy note 2 (sprint version). What are the odds someone has figured out how to get power and otg working on the note 2?
erica_renee said:
there is NO data and charge at the same time. This is due to how the device switches from charge to usb mode thru the pin 4 . it senses rather a data cable or charge cable is being used . will not charge via otg..
there are several threads with experiments trying to get this work .You could use a wifi or bluethooth drive for data...
Click to expand...
Click to collapse
Ofcourse there is charge and otg at the same time by just simply shorting pins 4 and 5 with a resistor,in my case for xperia p , a 100k resistor does it.
Timurs USB ROM from another site is what you want. Has links and everything you need.
I was going to do a car install as well but after sourceing parts and work estimates ( I want clean install, like stock) just more hassle than its worth for me. Please post pics if you get an install going.
Sent from my Nexus 7 using XDA Premium HD app
It says it's only been tested with CM10, but might also work with other ROMs. I finally got my Y cable, and I can confirm it works. [Using this cable from ebay, $6]
http://mehrvarz.github.com/otg-power-nexus7.html
This means you can plug in your flash drive or hard drive and use it while on AC power!
Update: for 4.2.x check this dedicated thread over on rootzwiki: http://rootzwiki.com/topic/37755-timurs-kernel-robust-usb-host-power-management/
Big thanks to XDA member t1mur and rootzwiki Timur for making the kernel!
This is awesome, just need to find a y-cable to try this out. Just hope its a stable kernel that doesn't cause any issues.
This is a great step in the right direction! Can't wait to see where this goes..
Hi Guys,
will this also work with a standard otg-cable and an usb-hub?
Cheers,
berkley
berkley said:
Hi Guys,
will this also work with a standard otg-cable and an usb-hub?
Cheers,
berkley
Click to expand...
Click to collapse
I don't think so for 2 reasons. Usually even powered usb hubs don't give out power through the input port [The source port of the hub]. And even if it did, it would be 500 mAh [the N7 charger is 2000 mAh], which [edit:] isn't enough enough to charge the N7 with the screen on. If the screen is off though, it will slowly charge it.
Also, apparently this is already implemented in Faux's beta kernel, you have to use echo to enable it [it's explained on the thread].
i am getting the 16GB. i am tired of waiting. I have one last question though. Can this in any way cause any type of damage on my device?
It's allow usb and AC charging or only usb ?
Awesome news, even though I just bought a regular OTG cable about a week ago for a $1.50 (still waiting for it to be delivered from China to the USA [NJ]). Since I just got a full-time job I'm going to sell my 8 GB and get one of the 32 GB versions when they become available so I won't have to worry about the extra cable
Can anybody confirm that it effectively works ?
Also, It would be good to to know:
- which Y-USB-OTG cable is used ?
- which power source, i.e. from a PC (500 mA) or a charger (2 A) ?
Huh? I have this already in my kernel for a while now... This is NOT something new
http://forum.xda-developers.com/showthread.php?t=1804374
faux123 said:
Huh? I have this already in my kernel for a while now... This is NOT something new
http://forum.xda-developers.com/showthread.php?t=1804374
Click to expand...
Click to collapse
Can you tell us some details ?
I am a little confused. The link says...
When a host mode adapter was recognized, charging of USB slave devices will NOT be activated and instead vbus will be raised in order to accept external charge.
If I want to use something that requires external power like a usb thumb drive, and the charging of usb slave devices is not activated; where does the slave device get the power to function? Is that shared off of the Y cable?
I know exactly what your talking about I have one for my old touchpad, ill try it on my nexus 7 see if it works.
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Excited!
Can't wait for this! I'll be staying on top of this topic for awhile.
Alright I tried it using stock rooted using motleys kernel and while I could use a powered usb hub with 2 storage devices and a keyboard It wouldn't charge the N7 simultaneously. Although it didn't drain any power from the device either. Now this could be because of what I'm running or even one of the cords since I won't have a chance till the morning to test a couple more scenarios. All in all it definitely should be possible but may require a different kernel/rom etc. Though the OP asked the question regarding doing it w/o cm10 so ill try and stay within those parameters. On the touchpad I used to do it with cm9, as it was necessary especially with that device mostly only working with its 2amp charger. The reason I would only question cords used is I had previous trouble with an older kindle cable and when I tested it on a device I needed 1.5a it was hovering around 1.35a using my multimeter. Which was causing my Touchpad not to charge because it requires alot of power to charge. Ill update you on any progress and see I'f I can find the link foe the Ycable which I got on amazon awhile back.
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I'm gonna have to do this. With this I will be able to finish my otg case
Sent from my Nexus 7 using XDA Premium HD app
I just read the code for the patch,its definitely looking like it will rely on the kernel as atleast in cm, USB slave charging mode needs to be suspended when recognized as host adapter. Regardless, I believe another Dev already implemented this and I'm sure others will.
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Does anybody have this working with their Nexus 7 showing "Charging" on the Battery panel? The best I can get is "Not Charging" which does me no good for my car install.
dmexs said:
Does anybody have this working with their Nexus 7 showing "Charging" on the Battery panel? The best I can get is "Not Charging" which does me no good for my car install.
Click to expand...
Click to collapse
nope, i'm in the same boat as you...wish we could somehow trick the system but alas not yet!
daclothe said:
nope, i'm in the same boat as you...wish we could somehow trick the system but alas not yet!
Click to expand...
Click to collapse
Yeah. Now I'm toying with the idea of mounting a network share from a NAS-enabled router and put that in that in the car instead...effectively freeing up the USB port for full normal charging. I don't really like this route though because I suspect waiting for the router to boot every time the car is started will slow things down.
I was one of those that ordered the magnetic pogo charger when it first came on sale and I am still waiting to see if I will get my cable.
So for those who are looking for something that could boost charging time I came across this while following the CES convention bloggers. It looks semi promising. It claims it boosts the amp of any USB port as well as wall charger by using this tiny adapter. Here's the official post about it take a look at it let me know what you guys think.
http://m.cnet.com/news/chargedr-lets-you-charge-your-tablet-from-a-laptop-usb-port/57563162?ds=1
From my understanding its our tablet that is preventing more draw from the usb cable not the output of the wall charger.
Sent from my Nexus 10 using xda app-developers app
I'm thinking they purposely slow the recharge to preserve the life of the battery, as this tablet is really designed as a template for the next gen tablets. I'm assuming that this tablet will be in the hands of many devs and constantly being charged and recharged more so than an average consumer device.
Sent from my Nexus 10 using xda app-developers app
That product looks interesting, but I wonder how safe it is. If it's making the USB port from the source actually draw more power, couldn't that cause issues and even trip some voltage-protection stuff on certain motherboards on computers?
It might trip the USB controllers when it draws too much (in modern computers this wont be permanent damage). This is stupid though, there's a reason the tablet manufacturers limit the current draw when it's connected to a computer's USB port.
rp181 said:
It might trip the USB controllers when it draws too much (in modern computers this wont be permanent damage). This is stupid though, there's a reason the tablet manufacturers limit the current draw when it's connected to a computer's USB port.
Click to expand...
Click to collapse
Yes there is a reason so consumers gets aggravated. And smashing the device and than order a new one lol
Does anyone know of a charger USB cable with a really short / stubby micro USB plug piece? I have my Nexus installed in the car, and due to the size of the plug that goes into the Nexus, it gets pushed to an angle by the dashboard, which causes things like my USB flash drive to unmount suddenly, USB-DAC to lose signal etc. I have tried both with the charger plugged directly into the Nexus, and using a 90 degree adapter, both are just slightly too tight and I am afraid with the pressure on them may cause damage to the connector on the Nexus itself.
I am hoping to find a USB cable with a stubbier plug, or possibly even an OTG cable with a 90 degree connector on the end of it. Either one of these should give me an extra couple mm in order to not run into this problem.
Thanks.
Have you tried something like this?
http://www.amazon.co.uk/Micro-Cable...1_1?s=computers&ie=UTF8&qid=1363605833&sr=1-1
Sent from my Nexus 7 using XDA Premium HD app
dicko1975 said:
Have you tried something like this?
http://www.amazon.co.uk/Micro-Cable...1_1?s=computers&ie=UTF8&qid=1363605833&sr=1-1
Sent from my Nexus 7 using XDA Premium HD app
Click to expand...
Click to collapse
Thanks for the link, I have not tried one of those (yet). I did find this link searching around yesterday and ended up ordering the down angled cable. It's not cheap for a 5" USB cable, but should work and give me a little extra slack for plugging/unplugging the Nexus.