yashsingh1/xdaforums huggingface dataset:
[Nexus 7 General] mvmacd:
What would happen is you can only use the storage while discharging the battery. The result? Constant running down of the battery, decreased battery life [as opposed to only using battery when you are away from AC power], and increased annoyance that the battery is dead and you must charge it.
[Nexus 7 General] a03dugga:
Is this still being worked on? No real updates for a while.
[Nexus 7 General] nst6563:
I have moved locations and have been busy with that for the past few weeks. I was hoping all our problems would have been solved by the time I got back around to trying this but maybe not :(
[Nexus 7 General] a03dugga:
Yeah unfortunately the development has come to a standstill.

Seemed like a really worthwhile project. :(
[Nexus 7 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.
[Nexus 7 General] random1204:
If this were done/possible - I would LOVE IT. I've been peeking around at these threads - because I'm at the point of debating selling it. I can't stand not having freakin' space. I have a 32GB and a 64GB MicroSD - just not a freakin' slot to put either of them in. So, overall, I really hope this gains momentum again and it's able to be easily done...
[Nexus 7 General] mvmacd:
Not to be off-topic here, but one workaround would be to get a OTG charging cable [or OTG and Y cable], and use the OTG + charging mod, found in faux123's kernel. I know it would only work when you're plugged in, but it's better than not having enough space.
[Nexus 7 General] Nikguy:
Its slightly less convenient but why not just use a otg cable with a micro sd card reader? I have most of my stuff on SD cards and even install apps and games on them with some use of the directory bind and stick mount apps.

But I agree with you that it would be sick if they could get this to work!
[Nexus 7 General] Milamber33:
It will be interesting to see what hardware changes there are with the GSM Nexus 7 coming out soon. Maybe something could be done with that?
[Nexus 7 General] N@th_OC:
Sorry for the off topic, but i need to ask someting to Milamber33.

Hi Milamber!

I see you're R.E. Feist addict too?
[Nexus 7 General] t_007_v2:
Shouldn't we call him pug? The rift war saga is some of the best fantasy great great books.
[Nexus 7 General] Milamber33:
Yep! I gotta say, though, more recently I've been getting hooked on Brandon Sanderson. The Way of Kings has possibly the most brilliant worldbuilding I have encountered. Ever. I can't wait to see where he takes it with the rest of the series.

Lol, that's a type of dog. :p His Kelewan name is much nicer.
[Nexus 7 General] N@th_OC:
Agree!

And thank you for Brandon Sanderson, I do not know him.

I will buy his books very soon. you made ​​me want to read him!

Thanks a lot man!
[Nexus 7 General] SubliminalME:
[offtopic] If he's good enough for Robert Jordan, he's gotta be good! [/offtopic]
[Nexus 7 General] JohnShaft69:
on topic

everyone pls pm each other if you cant stay on topic. its not rude of me to ask.

any progress on THIS TOPIC?
[Nexus 7 General] t_007_v2:
Topic looks dead and pretty moot. why don't you just go out and buy yourself a 32gig N7? (;
[Nexus 7 General] BikerBoy030:
Because of the price?!

Gesendet von meinem Nexus 7 mit Tapatalk 2
[Nexus 7 General] Sharpen3d:
There are those of us who already have perfectly good N7s, but are a bit limited by having an 8GB model. Now, yes, we can mount flash drives and USB memory via Stickmount (or Nexus Media Importer, if you're not rooted). You can use g-script to keep obb memory for games like Horn on swappable media, thus making life easier (or DirectoryBind, whichever). And yes, there's currently a patch for CM10 that let's you charge and mount at the same time (though it seems rather fickle and doesn't work with any cords I currently have).

At the end of the day, this potential mod would just be the most convenient and satisfying way to really expand the Nexus7. Swappable memory without a honking dongle on one end keeps the N7 in a beautiful, streamlined form. Simply saying "just buy the bigger model lol" is counterproductive and kind of a douchey comment. I think that it would behoove all of us to find some way to stay on topic, stay positive and offer any support or suggestions to the potential developers that we can.
[Nexus 7 General] morbidpete:
Sold mine, I'm out lol

-Pete
[Nexus 7 General] snook237:
Just a suggestion for large storage solution...

I just purchased the Gauntlet Node by Patriot Memory. It's an 2.5 external HD case with 5.5 battery and works like a portable WIFI hotspot. So far, after installing a 500gb/7.2k rpm drive inside, it works really nice to watch 3.5gb sized avi and mp4 files to both my N7 and iphone 4s. I haven't figured out how to access it wirelessly from my Window 7 laptop though. But it came with a USB cable that also charges the battery. I like how it also acts a WIFI repeater for my home wireless network. On sale at Frys for less than 90$ (HD was ~$69). Should be nice for long car rides with the family. My storage issues are no longer a problem! :good:
[Nexus 7 General] brad_wp:
My guess is this topic is dead unless someone other than the OP has done anything on it see this post by the OP on the Galaxy S3 board almost a month ago.

This is really unfortunate because I was really looking forward to the conclusion.
[Nexus 7 General] NamenIos:
According to the incomplete schematic floating around here the 3g module is connected via usb (pg 14). The position of the 3g module leads to my assumption, that there have to be the pins V5 USB2_VBUS (SNN_USB2_VUS), T6 USB2_DN, T5 USB2_DP and W4 ACC2_DETECT somewhere in the near and we could use them for a hub/sdcard reader etc..

Can anyone check if the big vias/holes right below the ME370T REV. 2.4 could be those pins? You would have to remove the solder mask on the pins with a fiber brush to be able to solder or measure those pins. I am not sure but i think you have to pull the accessory pin (ACC2_DETECT) down to ground level in order to activate usb host mode and it - can anyone confirm that? It should be the same as with the USB port that is connected to the SMB347, analysis of the smb347-charger.c could help. The best would be a Nexus 7 3g tablet and a multimeter.

I'll attach a picture of the holes and the relevant schematic page.

Is this the most relevant topic for that kind of information?
[Nexus 7 General] osmium2:
Great finding from the schematic!

I believe the big pads you found on the board is in fact the conn1 connection on the reverse side of the board. conn1 is the USB connection on the bottom of the device. I think we can quickly confirm this by a multi-meter.

Now what we need is some internal photos of the Nexus 7 3G, and see whether we can trace the USB connection from it.

Anyone own a Nexus 7 3G and can take some high res internal pic?

Updated: I found a side by side photo of Nexus 7 vs Nexus 7 3G internal. Look like the board changed a lot.
[Nexus 7 General] NamenIos:
Can you post the link to the photo please?

Edit: Nevermind, I guess I found it http://xdaforums.com/showpost.php?p=34807808&postcount=31
[Nexus 7 General] bigbop:
The iFixit website has some hirez pics of the N7 board.

If you have the FCC-ID number of the device, head on over to http://transition.fcc.gov/oet/ea/fccid/ plug in the ID number, choose the Detailed link and click on Internal Photos. Those are probably your best bet.
[Nexus 7 General] jb user:
I'm following this thread with great interest. I'm new to the world of tablets, but have some experience of modifying laptops, notebooks & palmtops. Feel free to correct me if any of my assumptions are wrong.

I'm not fully up to speed with tablet technology/chipsets, but I assume the relationship to x86 hardware is close. The chipset must contain a root hub for the USB, which means there should be at least four USB ports available somewhere on the mainboard, one being the charge/OTG connector, others, I would guess are used for the WiFi, GPS, docking port(possibly) & if fitted GSM. On most laptops the low res webcam is usually USB.

So, has anyone positively identified any of the other USB ports, or is the camera USB?

If the camera is USB, then the innards of a small hub could be used to share that port with a card reader.
[Nexus 7 General] bigbop:
Unless you're willing to unsolder the Tegra 3 CPU chip from the board to help with tracing the specific data lines for the various interfaces, you will have a tough time locating the other USB ports. Have a look at the Nexus schematics mentioned above. You will see the references to the ports that were removed. The cameras use the dedicated camera interface of the CPU. Personally, I would love to find the 6 data lines for the SD card interface and pull them out to a socket. Google had Asus remove them and the HDMI data lines to reduce costs.
[Nexus 7 General] Sopilou:
Why not use Mini-Display port? (free royalties)
[Nexus 7 General] jb user:
OK, so the camera isn't USB, is it possible to get the OS to show a list of attached USB devices? I won't be pulling my new N7 to bits just yet, but I have managed to get an 8Gb one off eBay with a damaged touch screen to play with.

If I can get a copy of the schematics (the link doesn't work for me), I will be able to find the USB data lines on the mainboard.
[Nexus 7 General] jb user:
Having managed to download the schematics and the Tegra 3 data sheets, and then spending the last 3 hours studying them, I have discovered the following:

Using the OTG connector for Internal storage would only be possible with some form of physical switching of the data and ID lines, the connector is hardwired to both the processor and the charging circuit. While there is a data device connected, it is unlikely that the charge control circuitry would allow high current charging to take place through the OTG connector even with a custom kernel, it may however be possible to trickle / maintain the battery while using the port. There is no electronic reason (I can see) why high current charging can't take place using the dock connector while the OTG connector is in use.

The Tegra 3 processor has 4 available USB ports, there is only mention of three being used on the schematics. USB1 is directly connected to the OTG connector, USB2 is used for the 3G module, USB3 was intended to be used for the side dock (POGO) connector (but this has not been implemented).

There is a connection to the Tegra's UART through the headphone connector, it appears to be a debug connection, and I doubt it will be of any real use.

I think our best hope of internal USB will be from the USB2, it should be easy to find on a 3G equipped unit, less so on a WiFi only (like mine) version. Dependant on soldering skills, it could be possible to break into the data lines on a 3G unit and install a small hub.

When my eBay unit arrives, I will get onto it!!
[Nexus 7 General] funkysam78:
Hello people, 1st post so be gentle, have had a nexus 7 afew days now, loving it but the lack of memory is annoying, have had a look at various threads and have had a play with it. My speciality is hardware so I think I can help, I'll have to make a vid on what I've tried so far but I may need a board from a smashed N7 to trace points.

The data lines go to the power module directly below the FPC connector and then to the tegra 3. I haven't got a dead N7 otherwise I'd test further. I'v opened mine a few times now, don't want to do it again and again, all tabs are intact.

Removing the tegra shouldn't be a problem, pin pitch doesn't look that much smaller than a nand flash though having a pinout of the actual tegra 3 would help loads in finding the SD and usb 2/3/4 etc

I'm keeping an eye out for dead boards
[Nexus 7 General] brad_wp:
Here's a random question. How would the OS view an internal memory card? Would we be able to install apps to it or store Google play movies/TV shows to it? Or would it be integrated like a flash drive with OTG where you can really only use it as file storage?

Sent from my Nexus 7
[Nexus 7 General] bigbop:
Will you be able to share the Tegra3 data sheets? Are they hardware or software data sheets?

It would be great if the unused USB ports came out to some of the test points (small copper colored dots on the PCB used during bed of nails PCB testing at the factory). Typically, when ports like these are not used, they are tied high or low. When tied high, it's usually through a pullup resistor. If someone has the programmers reference and can write a small pgm to check the USB ports to see if they're high or low, that would be a start.
[Nexus 7 General] funkysam78:
Search for 'me370t.PDF' its dropbox'd by someone, comes up as the second link for me
[Nexus 7 General] jb user:
The processor data sheets are available on the NVIDIA developer website, you can gain access by creating an account then requesting. The hardware information is limited, it is aimed at software rather than hardware development.

I'm good with hardware mods, but rely on others more knowledgeable to deal with the software 'tweaks' needed to make things work. What I could do with is a way of viewing what connected USB devices the processor can see (something as simple as windows "view devices by connection" would do). I have access to the test gear needed to find the data lines.
[Nexus 7 General] bigbop:
It seems you're doing the same as I am here. Another h/w geek. You might want to look at XDA user Chainfire's apps. One is Stickmount and the other is a USB diagnostic app.

What test equipment do you have to find data lines that might not even be hooked up to the outside world? Personally, I thought someone could write a small app that would toggle the extra usb/sd/hdmi data lines at a specific frequency and then use a small antenna probe and spectrum analyzer to probe the motherboard to find the line(s) with the signal.
[Nexus 7 General] fmap4life:
I definitely will be looking at the schematic tomorrow. thanks for the info
[Nexus 7 General] chrigi.senn@gmail.com:
Might I also suggest to look for any SPI interface or GPIO's. SPI wouldn't be the fastest possible way to access a SD-Card but it's simple. The protocol itself could also be implemented with a simple driver over GPIO.
[Nexus 7 General] androidfr33k:
A little off topic and sorry but where would the JTAG connections be on this board since it been taken apart maybe someone would know? Which connector or pins on the board?

I want to test to see if I can recover a completely bricked bootloader through JTAG if the connections are easy?

Thanks
[Nexus 7 General] bigbop:
The JTAG pins are located on the unused con1 connector beside the speaker connector on the other side of the board. Check out the schematics for the pin out. Schematics links are in some of the various threads. Search for me370t and schematic.
[Nexus 7 General] stoatwblr:
Switchmode regulators

No it's not. If you use a more modern inverting (switchmode) regulator it'll work just fine (they dissipate a lot less power than linear regulators so the extra cost is usually worth it on battery-driven kit.)

Search on farnell.com for "Linear Regulator Drop In Replacement". Farnell and RS have other (smaller) ones available too.

if you can find an internal usb port then 5V should be obtainable from that anyway.
[Nexus 7 General] rohan32:
Wow, looks really nifty and would be awesome if it becomes working! Keep up the great work OP!!!
[Nexus 7 General] bigpetefox:
That would be awesome if it works! I'll be paying close attention to this topic..
[Nexus 7 General] zZDave_Stud:
Looks pretty awesome! Can't wait 'till the OP finishes this and maybe puts up a tutorial. That would probably make the front page of XDA (everyone start voting for it!). And just think, if this is possible, then it could be possible to add a rear camera or MHL! Anyways good job!
[Nexus 7 General] Novalis31:
I would almost rather have the camera there since I use cloud storage mostly.
[Nexus 7 General] willis936:
Cloud storage doesn't much help when you want to play games, have multiple backups, and a slew of ROMs to switch between. I'm already having to make cutbacks (deleting two games) on my 16gb and I've had it for two weeks. There are no pictures, music, or movies on here either.
[Nexus 7 General] nst6563:
Same here. Poor design decisions there. I'm working on a similar concept over on rootzwiki just don't have the time to really dive in. I think the biggest hurble is going to get the tablet o use the extra storage and charge at the same time - that is if the op is trying a usb-otg method. Possibly a way around it with some kernel or other software via the hnp specification but I'm not a developer.
[Nexus 7 General] giveen:
If you can this to work you could probably make some decent money to modify peoples tablet for them. Not sure on the cost of your parts but I would be willing to spend $50 or so for being able to add a card.
[Nexus 7 General] ED2O9:
Just a quick heads up... the two red leads coming off of the battery aren't 7.4V. It's a two cell Li-poly pack, and they have leads for each battery. The red wires are each 3.7V, so my idea to use a 5V voltage regulator is out the window.

I've seen about a half dozen people trying this and it all still comes down to one problem: finding an alternate 5V supply. The data leads and ground isn't a problem. The way the micro USB port is set up, it's using the neutral lead on pin 4 as a switch. In it's normal state or when a charger cord is plugged it, the micro USB port works as a voltage "input", but when an OTG cable (which has the neutral lead spliced to the ground) is plugged in, it switches to "output" mode and supplies 5V to the attached device. Plug in a charger while the OTG set-up is running, and the switch shuts off and drops the external device. Supposedly, there's a workaround where you solder a resistor between the neutral lead and the ground and OTG works with charging, but I haven't had any luck. I've read resistor values of 32K Ohm - 100K Ohm working for various devices, and I've tried several values on the Nexus with no success. It we could find a 5V source, we could bypass the whole micro USB port and the neutral switch is a non-issue. I've tried searching for a source, but I've stopped short of disassembling the tablet to get to the front side of the main board.

Keep in mind this is just based on observations and research on my end. It's very possible that I'm wrong, and there's an easier solution.
[Nexus 7 General] bigrushdog:
When you're ready for implementation ill be happy to help. Find the block device the kernel makes, create mount point in ramdisk, add entry to vold.fstab for the volume daemon, jb should have needed framework, update permissions for external storage. Just gimme a holla. :highfive:
[Nexus 7 General] morbidpete:
Cant use a 5v dc-dc step up for the 3.7? They make then for the energizer cell phone chargers, maybe gut one or grab a parts list? I'll peek at digikey

---------- Post added at 02:45 PM ---------- Previous post was at 02:41 PM ----------

looking around they seem rather large, about 1" square, No idea where that could fit, Maybe desolder the components, Connect with magnet wire ( epoxy insulated) and hid in random spaces, Can you give me a link to the Micro SD board you chose, I might order these and see if I can squeeze them in somewhere in preparation for your finished products

---------- Post added at 02:48 PM ---------- Previous post was at 02:45 PM ----------

Found a super tiny one!

http://www.circuitsathome.com/store

---------- Post added at 02:52 PM ---------- Previous post was at 02:48 PM ----------

I hate to keep spamming this thread and my own reply, But I feel it is very possible to glue and connect the components from the above mentioned board to the bottom of the SD reader. What do ya think?
[Nexus 7 General] slybunda:
well how do you expect to charge a 7.4v battery from a 5v power source such as usb?

if you didnt know that much then you should quit while your behind.
[Nexus 7 General] espionage724:
Just incase it wasn't mentioned, the NFC is.. on the back of the casing itself (take off the back and look for yourself at the square rectangular box labeled NFC antenna :p) The antenna then connects to motherboard via those tiny metal contacts.

And to try to eliminate any further confusion, the empty spot was for a Rear Facing Camera. Since the final design of the Nexus 7 tablet has no camera, the spot remains empty.
[Nexus 7 General] ED2O9:
Thanks for your contribution! Your input really helped to benefit the XDA community as a whole. Now, where the hell is that sarcasm icon...

Anyhow, thanks for the previous contributor for the step-up link. I'll check tonight to see if 3.7V is sufficient to power the flash drive, if not I'll look into ordering one of those circuits.
[Nexus 7 General] Razor512:
don't have a nexus 7 (hoping to buy one soon), but a 3.7V power source will not power a flash drive, Just tried with an old 64MB flash drive by clipping the 2 power pins then attaching some wires then taping it to a 3.7V cellphone battery while connected to a USB extension cable. the light comes on but the computer doesn't detect the drive.

PS I currently use one of these USB chargers and have the wires connected to a 3.7V li-ion battery designed for a dell axim x51v (since the charging dock has a battery slot (have the wires glues to the contacts at the corner so it can still be charged) :) http://www.ebay.com/itm/Emergency-USB-Battery-Charger-2AA-with-Flashlight-for-iPhone-4G-3G-3GS-4S-iPod-/180836124278?pt=PDA_Accessories&hash=item2a1aac4676

really hoping for a working sd card mod for the nexus 7, (one of those will make it the ultimate low cost tablet (I will add a 32GB micro sd card to it)
[Nexus 7 General] demandarin:
I agree with the xda news writer. Just wanted to thank both of you as I ran out of thanks for the day. Great to see developer, Bigrushdog, offer assistance on the software side once this is ready to be implemented.

I know this would be huge and make headlines across all the major techsites like Xda. im sure Asus and Google would take notice also. Definitely will be keeping an eye on this thread.
[Nexus 7 General] iAppleDev:
You might want to check this out:)

http://xdaforums.com/showthread.php?p=30746531
[Nexus 7 General] jamesst20:
Really awesome! Does it actually work?

Envoyé depuis mon Nexus 7 avec Tapatalk
[Nexus 7 General] mgori:
/\/\ jackass alert!

@OP this is amazing! I can't wait until its done, I am willing to try it out :D Great job!
[Nexus 7 General] tuananh15986:
Adding micro sdcard is impossible !!

I have ME370t schematic,

Real J1 :D

In design schematic

it 's just debug connector !

No microSD card Interface

So we have no way to mod microsd card :crying::crying:

About CON3 for rear camera
[Nexus 7 General] stingfeelgood:
@OP I wish I knew more about resistors, ohms, watts, voltage etc because I would love to help. But I just want to say that this is an incredible thing that you are trying to do. I really hope it ends up working. Not just for the community benefit but for your own. You have the potential to make some money if this takes off. Great job and keep on truckin'! :)
[Nexus 7 General] nst6563:
Post the entire schematic for everyone. I see GPIO pins available according to one picture. These can be made use of as they are in routers that did not have sdcards (and were modded to have them with support from the OS like dd-wrt).
[Nexus 7 General] taffypride:
man this is awesome work. Is there any way to expand on this and maybe add in a Rear Camera?
[Nexus 7 General] damengual:
Anyone pursuing a camera add on?
[Nexus 7 General] vn00914361:
Damn, this stuff is so frigging cool!!!