HowTo: Root Nexus 7

Knowledge Base
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Why you would want to do this: You want your Nexus 7 to stay powered on at all times with the Kegboard plugged into the micro-USB port. Stock Android powers the Kegboard, but you cannot charge the tablet at the same time. This method allows you to both power the Kegboard and charge the tablet at the same time.

Please note that rooting or otherwise modding your Nexus 7 voids the manufacturer’s warranty and has the potential to brick your device forever! Kegbot/Bevbot is NOT responsible for any negative outcomes that may arise if this procedure causes you any problems! This procedure is provided as a courtesy to curious users and we make no claims to its effectiveness or reliability.

ROOTING YOUR TABLET WILL ERASE ALL EXISTING USER DATA! PERFORM A BACKUP!

[Download Android SDK Tools] (http://developer.android.com/sdk/index.html)

This needs to be installed on your personal computer. It is a development environment that will be used to send commands to the Nexus 7.

  • Unzip the downloaded package to your chosen destination
  • Double-click on SDK Manager.exe in the root folder of the downloaded package and wait for packages to load
  • If the button on the lower-right says Install 1 package..., click it. Select Google USB Driver, then Accept, then Install

Download Tablet Image & Files

Warning! Be sure that you are downloading the correct files for your Nexus 7 version! The 2012 model is codename grouper while the 2013 model is codename flo. It is your responsibility to know which model you have, and which items to download. We highly recommend verifying the MD5 of your download against the known MD5 of the release before proceeding.

2012 / Grouper

2013 / Flo

Move Downloaded Tablet Image & Files to sdk / platform-tools in the Android SDK directory you extracted to above

It’s important for these files to be in this folder so they can be accessed later.

Upgrade Stock Nexus 7 to 4.4.2 (KitKat)

You can do this through normal means. Click Settings -> About Tablet -> System Updates. Depending on your existing operating system, it may take several updates to get to 4.4.2. Verify that Android Version in About Tablet is 4.4.2 before proceeding.

Prepare the Tablet

Enable Developer Options

  • Under Settings -> About Tablet, click Build Number seven times.

Enable USB Debugging

  • Under Settings -> About Tablet, click the new Developer options and enable USB debugging

Plug the Tablet into your Personal Computer

  • Your Nexus 7 will probably show up as a media device. You need the Nexus 7 device to use the Google USB Driver. Since there are a number of operating systems you may be using, we won’t cover how to install drivers for devices here; but you will need to attach the driver located in sdk / extras / google / usb_driver to your Nexus 7 device
  • Your tablet will now ask to Allow USB debugging?. Click OK.

Test adb (Android Debugger)

  • Within a terminal window, navigate to sdk / platform-tools
  • Type adb devices. Your device should now show up in the device list

Reboot into Bootloader

  • Within the same terminal window destination:
  • Type adb reboot bootloader. The Nexus 7 should reboot into the bootloader

Unlock the Device

Note: this step wipes EVERYTHING if it is your first time unlocking!
Verify that you understand that this step voids your warranty

  • Within the same terminal window destination:
  • Type fastboot oem unlock. Click the power button on the tablet to confirm
  • To reboot the tablet, press the volume up/down button until you see Power Off. Click the power button to confirm

Verify Unlock

  • Power-up the tablet. You will be greeted with the first-run setup flow, confirming that the Nexus 7 was unlocked. Fill out the information as you normally would
  • You will once again need to Enable Developer Options and Enable USB Debugging. Once again, confirm that you will Allow USB Debugging? on the tablet

Root the Nexus 7

Copy Kernel .zip to Tablet

  • Within the same terminal window destination:
  • adb push NAME_OF_DOWNLOADED_KERNEL_ZIP.zip /sdcard/NAME_OF_DOWNLOADED_KERNEL_ZIP.zip

Install TWRP Recovery Image

  • Within the same terminal window destination:
  • Type adb reboot bootloader and wait for the tablet to reboot into the bootloader
  • Type fastboot flash recovery NAME_OF_DOWNLOADED_TWRP_IMAGE.img. You should see positive confirmation in your terminal window
  • Power down the tablet

Boot into TWRP Recovery

  • Hold down the volume up and volume down buttons. Then hold down the power button for 3-4 seconds until you’re in recovery mode

Install the Custom Kernel

  • Press the volume up/down buttons until you see the Recovery mode option. Click the power button. You should be greeted with the TeamWin logo and the new TWRP recovery panel
  • Tap Install
  • Navigate to NAME_OF_DOWNLOADED_KERNEL_ZIP.zip and tap the file
  • Swipe to confirm install
  • 2012 ONLY: Navigate back, and tap Reboot then Power Off. You will be asked to Install SuperSU. Confirm SuperSU by swiping
  • 2013 ONLY: You’ll be greeted with the ElementalX UI. Continue to press Next until you’re greeted with custom options. We HIGHLY recommend choosing Stock options where available and keep Default options when a Stock option is not listed. When you reach the Other settings screen, tap Enable USB OTG+Charge mode. When you reach the Ready to install screen, tap Install ElementalX. The device will automatically restart when finished

Install Kegbot App

Do this through the normal methods.

Connect the Hardware to the OTG Power-Y Connector

  • Attach the tablet’s micro-USB cord between the Power-Y female micro-USB and the tablet’s wall charger
  • Attach the Power-Y male micro-usb connector to the tablet
  • Verify that the tablet is now charging
  • Attach the second micro-USB cord between the Power-Y female USB port and the Kegboard’s female micro-USB port
  • Verify that the tablet recognizes the Kegboard
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This is great and in depth. Alternatively, the Nexus Root Toolkit (http://www.wugfresh.com/nrt/) will do all the hard work for you, just enable USB debugging, install drivers and click the button for whatever you want to do. Easy.

1 Like
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@Cdh007: thanks for the tip!

Someone popped on IRC to say they were having trouble finding kernels for 2012 Nexus 7. Can anyone report success with nrt + that device?

4

I’d second the Nexus Root Toolkit, I haven’t used it on the N7 from 2012, but I’ve used it on the Nexus 10, Galaxy Nexus, Nexus 5, and the Nexus 7 from 2013. It’s served me well on all of em.

Of course rooting isn’t the issue with the N7 from 2012. It’s finding a kernel with usb host mode charging enabled.

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Has anyone tried the 2012 Nexus 7 charging dock (Amazon non-affiliate link) as an alternative of rooting the device?

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I had success with the ElementalX kernel for host-mode charging. However, this wasn’t sustainable for any significant period of time. I had three controllers feeding into a powered USB hub, then into the rooted Nexus 7 2013 with ElementalX. The tablet would initially see and communicate with all controllers while simultaneously charging, but after random periods of time would lose signal from the hub. I have seen posts in the old forum with the same issues. After replacing all cables, trying different hubs and different kernel settings, I gave up. I returned the Nexus and got the recommended Acer tablet. It worked flawlessly out of the box on the first try and hasn’t gone down since.

I would steer clear of the Nexus 7 for multi-tap setups. That is of course only my experience, I could have overlooked something.

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I ran a KBPM, and a home built keg board on a powered USB hub using a 2013 Nexus 7 and the OTG cable from the kegbot store. I never had any issues like that. Wonder if the power demands of 3 boards on the tablet is greater even with a powered hub?

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That could be the culprit.

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Are there any upgraded Android version compatible ROMs out there? I’m not sure if it matters as I’ve got things up and running, but there’s a part of me that thinks I should be running a more recent Android version - thoughts?

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Good question - I’m in a similar predicament. I decided to upgrade to Lollipop - 5.0 on my Nexus 7 2012 but I don’t think there are any kernels that do what Kangaroo Kernel did for 4.x (OTG + Tablet Charging). Kind of stuck waiting at the moment or considering a downgrade.

FWIW Lollipop is noticeably slower on the 2012. At least in my limited experience playing around with it. Downgrade is looking pretty good right about now.

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Thanks for the info - I should really learn to leave well enough alone, but so it goes…

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I just got my 2012 nexus 7 and it came with lollipop 5.1.11 preinstalled. Is downgrading really the only option at this time? Lollipop send pretty quick and snappy so I hate to change but…,

Anyone found a solution yet?

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Ha - must have been looking at at the wrong info - I am on 4.2.1 out of the box.

14

Has anyone tried anyrooter as an alternative of rooting nexus?

This doesn’t work on Nexus 7 with Android 6.0