yashsingh1/xdaforums huggingface dataset:
[Hardware Hacking General] littleguy77:
Well I know nothing about what is possible through the software side of things so that would be cool. I don't personally want to install a custom ROM but I'm down with apps that require root.

One thing I can say however is that no software in the world will help if you're trying to read an SD card and the stock charger is shorting the data lines together.

---------- Post added at 11:19 PM ---------- Previous post was at 10:48 PM ----------

OTG supplement to USB2.0 spec, section 5.1.1.

USB PHY must supply 8 mAmp minimum to meet spec. Is permitted to supply 100 milliamp if voltage stays above 4 V. Permitted to supply full 500 milliamp if above 4.75 volts.

I read a TI whitepaper that suggests never assume an otg device will supply more than 100 mAmp.
[Hardware Hacking General] js3kgt:
thoughts

I think it would be the best bet to have a user replaceable part such as the I/O cable that extends the micro USB above the battery.

I am unable to source the parts I need to try this, but what I'm thinking would be to have a normally closed surface mount relay between the micro usb and the nexus motherboard. While there is no power coming in to the micro usb the relay will close and short the OTG sense wire with ground to enable host mode. When power is provided to charge the device, the 5v will open the relay and disconnect the sense wire from ground. A few diodes will be needed to only allow voltage to be detected from the micro usb and not from the device in host mode, but I think this would be the best situation. Then software side all that is needed is StickMount to mount the external storage.

If anyone knows where the replacement I/O cable can be found as well as smb packaged n/c 5v solid state relays please IM me.
[Hardware Hacking General] iAppleDev:
Added OTG switch works great next to wire up HUB/card reader.
[Hardware Hacking General] iAppleDev:
So I soldered in a switch to id pin and ground pin of micro usb all was good, charged when powered on and switch off, charged when power was off switch on or off. Now I soldered microsd card reader power and data lines to the microUSB connector them ran the ground for card reader up to switch, it works fine for mounting sdcard, but it won't charge when N7 is booted up. It does charge still when not booted up. Maybe I should have ran the ground for the card reader to microUSB port too. But at least it works and is all internal.
[Hardware Hacking General] eBandit078:
Glad you got it working! I hope a custom ROM or something will allow the card to not only be mounted but be able to install stuff onto the card if you should choose to. Is that the only difference between yours and a regular tablet that has a card reader from the factory? You can see the card and transfer to and from the card but cannot install onto it?
[Hardware Hacking General] littleguy77:
Nice job. Yes that was my experience too regarding charging + otg. Running your card reader's ground to the microUSB port wouldn't have changed the behavior, so you can rest easy there.

Eventually I bet the kernel devs will come up with a solution to permit charging and OTG. So now all we have to do is get on those forums and start cheering them on ;).
[Hardware Hacking General] Mechanio:
I can confirm that the dock pins are 5V, HPOUTL2, HPOUTR2, & GND.

Also that when a real dock is attached, DOCK_5V pulls down DOCK_IN# (which tells the SMB347 to charge from the dock) and HPOUTR2 (the right headphone channel) is momentarily grounded to pull down LINOUT_DET, which tells the device to send audio to the middle two dock pins. (The headphone jack still works normally, turning off the dock audio when headphones are plugged in.)
[Hardware Hacking General] iAppleDev:
Update: I was up late and thinking about the no-charging while booted in OS. Thought I would change up the wires for microSD and switch for a better connection(s) and I hooked my microSD reader backwards and have messed something up with the ID/OTG somewhere- no more OTG, fast charge,adb or anything but slow charge. Lesion learned: hook the wires up right. So now I'm back to drawing board until I can figure out a fix or buy another one for testing, I know this will work with kernel mod/root and the right wiring.

I think an easy way that could be to make a custom ribbon cable that will replace the stock one and have the wires for an easy install.
[Hardware Hacking General] vggroup227:
this is cool .

Sent from my GT-I9100G
[Hardware Hacking General] FuzzyMeep Two:
I am an electrical engineer and i am willing to help. If someone can either, send the ribbon cable board from a borked nexus, or if you can get me a picture of both sides of the board layed over a ruler of some kind then i may be able to replicate it.

**having an actual board would be MUCH more reliable**

I could replicate the board, and add circuitry for an SD card socket and associated logic to the "ribbon board".

I think, if you used an otg adapter, (just the micro USB part capped at the end, so it barely sticks out from the port) to bridge the otg pin to ground, you could add a couple simple logic chips to switch the USB data/power from the output pins on the micro sd to the sd card (and associated SD to USB ics) when the otg pin is grounded. So plugging in a small adapter, would stitch the SD card on and allow instant access to external storage.

To add some credibility i have successfully reverse engineered a board that had almost 1200 pin pairs, so i think i could handle a small board.

I can create the Gerber files to manufacturer from, and maybe recommend a good place to have it made, but am not willing to pay for the manufacturing, although all i ask for my time is, if it works, one to call my own.
[Hardware Hacking General] littleguy77:
Now we're talking!

Now THAT's a great idea. That would be about as fool-proof as it comes, giving you almost everything you need without custom ROM/charger, without soldering, and without modding the case at all. Still can't charge and read, but it would do almost everything else simply and flawlessly.
[Hardware Hacking General] WiKDMoNKY:
Does anyone make a micro usb micro sd card reader? I have a usb to micro sb reader that is not much bigger than the USB port. If we could get something like that, it would be perfect. This is what I have http://www.geekstuff4u.com/media/ca...5/B/u/Buffalo-microSD-USB-card-reader_000.jpg
[Hardware Hacking General] dapezboy:
this is pure awesome! keep up the good work.

Hopefully I semi easier DIY tut will be in the works once you get this working.
[Hardware Hacking General] iAppleDev:
This thread is about internal USB mods!
[Hardware Hacking General] WiKDMoNKY:
I fully understand that, but until it happens, something in the meantime would be nice...
[Hardware Hacking General] drewski_1:
wouldn't you need an OTG-USB adapter too?
[Hardware Hacking General] chris9983:
could this be usefull

http://www.amazon.com/Black-4-Port-High-Speed-USB/dp/B002FFT8Z6/ref=pd_bxgy_pc_img_y

Great work on this project!
[Hardware Hacking General] eBandit078:
Unless it had a built in USB OTG it wouldnt work anyway (I believe). I am plan to use a usb to micro sd adapter as my reader for this mod, but that is just for the card reader part. The one I posted a pic of previously isn't any thicker than a SD card. I know what you saying, but I do not think you can do that unless it had OTG built in.

All of us here want it internal though. We (at least not myself) don't want stuff hanging off the usb port. For that we can have USB OTG cable, usb to micro sd reader and have it tucked away inside a small tablet case.

Sorry about your tablet iAppleDev :( Any idea what parts you may need to get or where to get them? What kernel mod were you referring to?
[Hardware Hacking General] iAppleDev:
Thx, I hope/think its just the IO-usb/headphone-ribbon or ?software? But at least it still works fine as normal tablet just no adb/custom recovery as I didn't unlock/root it yet:(

Now I need to try and convince my wife that the kids really need a nexus 7 because the iPad 1 they have and use is to old and is outdated and then buy an 8GB for more testing and give my 16GB to the kids:)

Kernel mod=http://mehrvarz.github.com/otg-power-nexus7.html
[Hardware Hacking General] eBandit078:
Thanks. Hope you get it sorted or get another.

I need to root unlock/root mine yet as well. I am going to do that before I hack into it probably. I want to carefully read all your past posts before I do as well, ;) *

*sweet we get Jelly Bean 4.1.2 now with no more locked home screen rotation.

Do you know where to order spare ribbon etc? I have tried where to find stuff like that and cannot.
[Hardware Hacking General] eBandit078:
Any updates on your tablet?
[Hardware Hacking General] ewoewo:
praise the soc designer

I was sent here on the behalf of the god of the soc to tell you that you just need to check out the pins on the

edges of it and the pcb to locate the 2nd and 3rd usb and the sata and the hdmi...

http://xdaforums.com/showthread.php?t=1963894

this is also available with the 4412 and the rk3066. let us praise the god of the soc together now!
[Hardware Hacking General] aselker:
http://www.mrgadget.com.au/catalog/images/Targus_Mini_USB_2_Travel_4Port_Hub.gif

Useful? I have seen one of these up close, the actual board is tiny and incredibly thin, if you remove the actual ports.
[Hardware Hacking General] Renate:
I don't know about any 2nd or 3rd USB interface on any device, but most certainly don't have them.

If you're willing to sacrifice being able to use the USB interface in peripheral mode,

then installing a miniature hub PCB in your device would work fine.

If you want to be able to switch back and forth between peripheral and host mode,

then you'd need a couple of data multiplexors.

You could wire it so that the flash drive is always on a port of the hub

and the input to the hub and another port switch between the jack and the system.

Somebody with know-how could make a tiny board with 2 muxes and a 2 port hub.

Of course there would still be the question of direction control.
[Hardware Hacking General] JunDavis:
Would this be possible for only the nexus 7? Or maube some similar devices? :D
[Hardware Hacking General] xdej:
WiKDMoNKY gave me the idea of using really small boards for microSD (with casing removed)

and from the usb hub suggested by aselker:

If the SD card does not fit well (for example in padfone 2), a 16GB usb drive may fit: and there also exists a 32 GB version of this usb drive.
[Hardware Hacking General] xdej:
Here is a picture of the opened "word smallest" microSD card reader:
[Hardware Hacking General] xdej:
This contains a small board with two USB ports and one microSD port combined (thumbnail attached). One board instead of two !
[Hardware Hacking General] jonra:
No Charging while in host mode

Just in case this is not (yet) known: This (srry, not allowed to post direct link: mehrvarz.github.com/usb-host-mode-power-management-nexus7 ) seems a very useful approach to get around the "no charging while in host mode" problem.
[Hardware Hacking General] funkysam78:
Thats the little begger I'v been looking for, I knew I'd see it somwhere. I'v done an external flush OTG adapter setup that sticks out about 8mm but I cant link yet (not enough posts) but this should make life easier for an internal one.
[Hardware Hacking General] xdej:
Thanks funkysam78, your posts lead me to this 5V unlimited source:

---------- Post added at 11:56 PM ---------- Previous post was at 11:50 PM ----------

You should read jb user's post, here is an extract:
[Hardware Hacking General] funkysam78:
I could do an internal micro SD slot right now, that's not the problem. The problem is isolating the power/data lines so they switch between the 2, I've done a test rig to replicate an internal SD slot and can get it to charge when there is no micro SD card in the slot but it only draws around 400mA. Obviously the charger is bridging the 2 data lines but the fact that there's power going to the card reader (even with sense not grounded) means the N7 isn't pulling 800mA as it should. I'll keep playing
[Hardware Hacking General] massimomex:
just need help guys ....my sensation xe stopped work properly ...telling ..sorry the process.android.process.acore has stopped..or something like this and touch it was dead ...so i decided to change the board ...the half ..and my touch tourned again ...but now i have no operator signal .....what it could be ?thanks in advance please help ....mangiaebevi43@gmail.com
[Hardware Hacking General] funkysam78:
For anyone following this thread check out this thread
[Hardware Hacking General] Kejpi93:
web cam - foto possible?
[Hardware Hacking General] :
Flip the current front facing camera so its at the back. Making a hole at the back of coarse.
[Hardware Hacking General] Kejpi93:
1.3Mpx - It does not pay to

www,tnij,org/tzab

www,tnij,org/tzad

, = .

possible?

I'm sorry English - translator :(
[Hardware Hacking General] :
I guess you could do it but its using a different camera and the connectors are different as well. You also need to have supported drivers. Maybe port the galaxy s3 drivers to the nexus 7. It could be a interesting project .
[Hardware Hacking General] xdej:
URL shortener are bad as they expire.

Here are the real URL you wanted to post, in english and in USD:

http://magboss.pl/article.php?currency=USD&lang=en&id=4353

http://magboss.pl/article.php?currency=USD&lang=en&id=29217
[Hardware Hacking General] Nazo:
I happened across this thread while Googling around wondering if I could rig up anything of this general sort. The lack of a built in card reader really sucks when everything else about the Nexus is just wonderful.

Anyway, I was about to give up when, while I was working on something else I was looking on the Wikipedia article for details on something and ran across this:

If I'm understanding this correctly (and assuming those are given in order) it sounds like all we would need to do is connect the ID pin to the ground via a 36.5K resistor and it would tell the device to stay in host mode AND allow charging at the same time. Unfortunately, I definitely don't have the selection of resistors I'd need to test this, nor a suitable potentiometer (I could have sworn I had a 100K pot somewhere -- though it was an audio one so not linear and would have been very hard to tune. Unfortunately I just can't seem to find it anywhere.) However, I may be misunderstanding. In fact, it may be possible that that last state is saying (or at least implying) "do not provide power to the port" which would mean the card reader would lose power when no power is connected.

I was kind of wanting to do this myself, though I'd want to keep it as simple as I could. (Preferably no modding of the casing itself. I'm fine with the reader being inside completely requiring opening the case if I wanted to get to it. The idea is just to make it possible to add on storage since I was cheap and got the 16GB model instead of the 32.) Actually, I'm not completely clear on where exactly there is enough room to squeeze in a micro-sized card reader or even just a USB connector.

BTW, did anyone ever try utilizing the dock connectors to charge while the USB was connected? I'm not sure what exactly could be done with this short of having a separate connector of some sort for charging, but it seems like maybe there's something to work with there? Even with a separate connector it might actually not be so bad I think -- it would just have to be really small or something (I'm thinking in terms of a 2mm coaxial connector or something maybe? It wouldn't be hard at all to just clip a few old USB cables and connect the power to something like that and shouldn't be terribly expensive, but of course first the connector would have to be squeezed into the Nexus 7's case somewhere accessible...)
[Hardware Hacking General] englishmale:
sorry if this is a bit noob but I'm not techie at all but what about using a watch battery for the 5volt power? or something like this https://www.sparkfun.com/products/10299?

Sent from my Amiga using workbench 3.1
[Hardware Hacking General] Nazo:
I'm pretty sure one of those would be quite insufficient. For one, it says 50mA max and I wouldn't be shocked if some card readers could be 100mA or more even. Even assuming 50mA is sufficient (some memory cards are pretty efficient after all) there's still no way it would last very long at all...

Also, the card would be powered 24/7 unless you found a way to rig up a power switch. I don't know if it can automatically go into a power saving mode without any OS to direct it (or if it would do so when the tablet shut down) but there would still be energy losses along the way, so it would slowly go down even while not being used...
[Hardware Hacking General] mazjed:
hi to evry one

Hi every body

its nice to see your team work and id love to work withe you >:highfive:

i have an idea that might be helpful but i don't have the knowledge that some of you have

i can confirm you that the eKit 4-in-1 Connection Kit used for Samsung S2 & S3 Multi-functional 4 in 1 Connection Kit : USB /SD Card/Micro SD/Micro USB Inputs

sorry i cant send you the link because im new her but amazon ( B006I31SHC ) and you will find it

is working as an OTG perfectly on our nexus 7 and it has :

1 Female USB Input (Great for reading thumb drives/external HDs )

1 SD Card Slot (for easy card reading)

1 Micro SD Slot (for easy card reading)

1 Micro USB Input (Used for additional powering of external Hard Drives)

Easy to manage and transfer files from any device - Plug your Digital Camera In directly via USB/Micro USB

so my idea is to play around and using the circuitry of the hard disk power to act as charging line to the nexus 7

i have the 4 in 1 adapter mentioned and id love to work withe you may be we get something out of it .

any how thanks for sharing and keep on the god work .
[Hardware Hacking General] mazjed:
some pictures

her are some pictures showing the size of the board

and the configuration

of curs most of the metal parts can be removed and the pcb will be around 2-3 mm
[Hardware Hacking General] GooStorm:
Hey all! Love this little project and wish everyone the best of luck.

Been trying to do the same thing myself and have so far ruined 2 USB connectors so progress isnt exactly quick.

I am a bit of a noob at all this but has anyone tried tapping into CON 3 for power? Pretty sure the OV5650 that was meant to be it in requires a fair amount of juice, maybe enough to power a USB?
[Hardware Hacking General] DaMadOne:
so when you plug this thing into the N7 can you actually use the SD card and charge at the same time? Im going to guess no, but maybe it can (that would be nice). Would have to add a switch to the N7 somehow to switch between otg and charging. OR also manage to shove in a small micro controller such as a teensy 2.0 with the ID pin of the N7 hooked to it with a small program to detect OTG or charging cable to automatically do the switching for us.

I was originally thinking of simply using the teensy with an SD adapter to act as the whole hub and switch but when I went googling about the transfer speeds the teensy is capable of (1-2ish MBit MAX) it would almost be pointless. Unless there was a way to hook an SD card reader to it and make it transfer those pins directly to the teesny usb connector and so the n7 usb controller could use it directly, which I don't think there is without more hardware.. hench my first paragraph talking about using it solely as a "soft" switch.

Maybe someone with more AVR knowledge could chime in?!
[Hardware Hacking General] noobOTT:
Know a bit about AVRs but I think What you might need is a multiplexer; if you want to switch D+, D-, and ID, the 4053 could be the best choice. You can probably sample a few from TI or something. Using an Arduino or a Teensy might be overkill and space-wasting. I you're really bent on using an AVR, an ATtiny is a bit less overkill.
[Hardware Hacking General] raddacle:
So has anyone actually got this working and was able to run the sd card and be able to charge while the device was on?
[Hardware Hacking General] LesserAnimal:
EBAY'D 6x 8gb MAINBOARDS FOR TESTING. Lets make this work here to apply towards n7 v2

So this thread and all related to it seem to have died which I don't get because the roadblock behind progress was charging in otg mode which fauxs kernel solves. but I'm determined to find internal otg solutions to what i feel are serious set backs to small form factor tablets that just can't be solved with(buy a pricier tablet). Even at 600 bucks I can't find a 7-8 inch that meets my peripheral needs and I'm also interested honing my soldering skills ass well as expanding my understanding of micro electronics. So please no "waste of money" nonsense as everything learned here can be applied to future USB otg capable devices. Namely the upcoming nexus 7(2) but as parts will be costly and rare to begin with I have a number of 8gb motherboards I've purchased to offer to the gods of science and burnt fingertips before applying to future tablets till wireless finally prevails or we find 6usb port tablets mass marketed. Im split between continuing this thread that seems most elaborate of the many Ive read.. Im not interested in pipedream smt memory replacemenf or opposed to a physical switch. Im talking about tapping into the USB circuitry to allow Simultaneously charging and use of a flashdrive/hub and having g the option for wired PC connection by turning otg off.

In short I will get new phones/tablets but I will not be starting any other projects big or small until I've made a working internal hub solution and guide to achieving it(for those who buy devices to tinker with more so than use not your average Joe looking to upgrade.

So far I've got another micro USB port connected directly behind the first pointing in as my internal tap. I want to wire a switch that grounds the ID pin and connects + - D lines to the nexus to engage the hub. The other position would place the tablet behind the hub so it would list along with all the other added devices when connected to PC. This might take cutting traces I'm guessing... And is where I'm gonna need some help figuring out. If this turns out impossible then disabling otg all together so the nexus can interface with PC would be my back up solution. When all is said and done I plan to comprehensively detail the proceedure so others may try.
[Hardware Hacking General] Renate:
Here's a couple of hints:

When trying to get this thing to work, you can just prototype all your stuff externally.

You can have a micro USB plug into the Nexus and a micro USB socket which will stand in for the Nexus socket until you migrate to the finished version.

To make this real, you're going to have to have a total of 3 USB DPST switches, that could be 1.5 USB DPDT switches.

If you can do without external USB devices, that's 2 USB DPST or 1 USB DPDT.

CD4000 series is not going to work. They have much too high an on resistance.

Real USB muxes like the TS3USB30 have much lower resistances.

The only way that I can see this project being a real win is if somebody has some PCB's made up.

You'd need at least one mux, optionally a hub, an MMC controller and a micro SD socket.

You'd also need some discrete stuff for power control and ID pin.

You'd need some way to switch direction of the USB flow.

You might snarf a GPIO pin somewhere off the motherboard.

You could add a physical switch.

You could have it that you need to insert a dummy plug in to pull down the ID pin.

When you are all done, the Nexus as a peripheral on a desktop will still not be able

to access the additional SD card, unless you add another multiplexer.

Even if you made this all up, it might be difficult to have some users here break the connection to the stock USB connector and wire up both sides.

No, I don't have a Nexus 7, which is why I am a bit aloof from all this.

I do use host mode on my Nook Simple Touch and I do charge while doing that.