Nexus 7 internal sd card.

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zZDave_Stud

Senior Member
Aug 12, 2011
248
76
Pennsylvania
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!

Sent from my Nexus 7 using xda app-developers app
 

willis936

Senior Member
Dec 6, 2011
52
9
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.
 
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nst6563

Senior Member
Mar 15, 2011
130
20
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.

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.
 
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giveen

Senior Member
Jul 6, 2010
2,174
1,560
Caldwell, ID
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.

Sent from my Nexus 7 using Tapatalk 2
 

ED2O9

Senior Member
Sep 2, 2009
295
129
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.
 
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bigrushdog

Inactive Recognized Developer
Apr 23, 2007
3,547
7,244
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:
 

morbidpete

Senior Member
May 20, 2009
125
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Portsmouth
www.plasstech.it
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.

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 ----------

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

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 ----------

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

Found a super tiny one!

http://www.circuitsathome.com/store

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

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

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?
 

slybunda

Senior Member
May 6, 2010
797
73
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..

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.
 

espionage724

Senior Member
Feb 8, 2010
2,921
727
wiki.realmofespionage.xyz
OnePlus 6
Dont see how this is possible thats the nfc unit where the sd card is being placed. No connectors are there to mount an sd card.
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.
 
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ED2O9

Senior Member
Sep 2, 2009
295
129
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.

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.
 

Razor512

Senior Member
Dec 17, 2009
143
12
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)
 
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demandarin

Senior Member
Apr 7, 2010
7,021
2,038
Alexandria, Va
It always pleases me immensely to come across such developments being made and shared here at XDA, even if I don't possess the device in question or don't have the necessary skills (or balls) to apply these hardware mods myself.

At the same time, it really saddens me to see many members here being total jackasses, responding rudely with their lameass remarks, downright DEMANDING the OP to release the work quickly, and even resorting to taunting them and calling it fake if it's taking them a while, when they have absolutely no idea about the whole thing themselves.

I am writing this post in support of all the developers like the OP here who are passionate enough about their devices to risk damaging them while applying such mods, and are more than happy to share the fruits of their labor here with the community, all without expecting ANY monetary compensation except for the appreciation of those they are kind enough to share their work with. It is completely uncalled for of the jackasses to behave rudely to them, while they are themselves not doing anything other than being free-riders, not contributing anything positive to the community, and at the same time spreading negativity with their crappy behavior.

While making use of the developments here without contributing any developments of your own is fine because obviously not everyone has the required time or skills for all of this, it's simply unacceptable to contribute negatively to a community that gives you so much for free due to the generosity of others, without asking you for anything in return. Heck, you don't even have to thank or reply at all if you choose not to; if you can't say anything positive, you can still just make use of all the developments here silently without saying anything at all. While it is encouraged and much appreciated, there's still no rule or obligation on showing appreciation being mandatory. Just don't go about being jackasses and being rude to the developers at least!

OP and other developers out there, please don't let what such jackasses say keep you from what you're doing. While there may be many of them around, there are still many of us who genuinely appreciate your work and understand the effort you put into it. Kudos to you, and thank you for making XDA what it is.

Before I finish my rant, I would request the moderators to be more strict towards such jackasses, as they contribute nothing positive here and at the same time likely drive potential developers away and harming XDA because frankly speaking, who would want to share the fruits of their labor for free with those who don't show appreciation respond back in such a way?

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:

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.
 
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jamesst20

Senior Member
Jan 31, 2012
1,674
2,190
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Really awesome! Does it actually work?

Envoyé depuis mon Nexus 7 avec Tapatalk
 

stingfeelgood

Member
Feb 3, 2011
32
6
@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'! :)
 

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    Comments by Jackasses and Development at XDA

    It always pleases me immensely to come across such developments being made and shared here at XDA, even if I don't possess the device in question or don't have the necessary skills (or balls) to apply these hardware mods myself.

    At the same time, it really saddens me to see many members here being total jackasses, responding rudely with their lameass remarks, downright DEMANDING the OP to release the work quickly, and even resorting to taunting them and calling it fake if it's taking them a while, when they have absolutely no idea about the whole thing themselves.

    I am writing this post in support of all the developers like the OP here who are passionate enough about their devices to risk damaging them while applying such mods, and are more than happy to share the fruits of their labor here with the community, all without expecting ANY monetary compensation except for the appreciation of those they are kind enough to share their work with. It is completely uncalled for of the jackasses to behave rudely to them, while they are themselves not doing anything other than being free-riders, not contributing anything positive to the community, and at the same time spreading negativity with their crappy behavior.

    While making use of the developments here without contributing any developments of your own is fine because obviously not everyone has the required time or skills for all of this, it's simply unacceptable to contribute negatively to a community that gives you so much for free due to the generosity of others, without asking you for anything in return. Heck, you don't even have to thank or reply at all if you choose not to; if you can't say anything positive, you can still just make use of all the developments here silently without saying anything at all. While it is encouraged and much appreciated, there's still no rule or obligation on showing appreciation being mandatory. Just don't go about being jackasses and being rude to the developers at least!

    OP and other developers out there, please don't let what such jackasses say keep you from what you're doing. While there may be many of them around, there are still many of us who genuinely appreciate your work and understand the effort you put into it. Kudos to you, and thank you for making XDA what it is.

    Before I finish my rant, I would request the moderators to be more strict towards such jackasses, as they contribute nothing positive here and at the same time likely drive potential developers away and harm XDA because frankly speaking, who would want to share the fruits of their labor for free with those who don't show appreciation and respond back in such a way?
    59
    Well here is a little teaser of my internal sd card slot for the nexus 7

    I figured this was the best forum since it's original and I developed it.

    More info coming later...

    20120902_141929.jpg


    20120902_142015.jpg


    Sent from my S3 using xda app-developers app
    39
    Damn some of you are pain in the asses

    The mod isn't done yet. I'm waiting on a mini voltage regulator to come in so I can finish soldering stuff up. That's why its a teaser

    And to you people saying its BS..that the NFC is there...shut the F up, you have no fracking idea wtf you are talking about.

    Also with the sdreader I'm currently using the pcb is a bit larger then I would like so it doesn't fit perfectly in the rear camera munt hole. I'm going to trim the board a bit to get it to fit snug. Or just get a new board made with a zif connector so I can connect a ribbon able.

    I still have the same issue as others do with the sdcard not being read when plugged in. I figure I should be able to tap into the rear facing camera connector pads (the pin headers are there to the right of the sdreader under the sticker) but if I do that I might need some software to be able to handle it.

    Also its hard without a data sheet for the board


    Sent from my Nexus 7 using xda app-developers app
    11
    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.

    ...

    3.3V should actually be enough to power an SDCard. I use a microSD in a data logger with an Arduino and this setup is just working fine.
    It would be interesting to see if a normal microSD to SDCard adapter is small enough to fit the space, as it's a really cheap way to interface these little cards.

    Might want to check these two websites:
    http://elasticsheep.com/2010/04/teensy2-usb-mass-storage-with-an-sd-card/
    http://www.frank-zhao.com/cache/fat_sd.php

    If we can find 4 free IO pins and a nice Kernel dev, there might be a chance to get it working.

    Edit: I think this explains it quite good:
    sd-teensy2-schematic.png
    10
    I don't consider this trolling, its stating a fact. Without proof you can only act on the evidence given. It looks fake

    running test & probing the board & having a temp 2gb card, plus a card reader connected on my bread board tyring to get this thing to work properly means its fake?

    how so...

    why would i post pics of it all connected to the bread baords since that is only for testing,...i rather show a pic of what it WILL look like once im finished...

    so go troll somwhere else