Asus Google Nexus 7 Custom Rom Android 7.1.2 (2012 Grouper WiFi Model ME370T)

This 2020 blog post tells you how to install a custom rom on the old Asus Google Nexus 7 ME370T (2012 Grouper WiFi Model), taking it to Android 7.1.2.

With the 2020 custom rom the tablet performs well. I’m able to use Facebook Messenger and Skype for video calls. Watch the BBC iPlayer and All 4 for movies and television shows. Listen to music via Spotify and TuneIn Radio. Plus play Angry Birds 2, Candy Crush Jelly Saga and use many other Android mobile apps.

November 2020 update: Since originally publishing this ‘how to’ guide in May 2020, I’ve just upgraded a second Nexus 7 2012 Grouper tablet. I’ve added additional details and download links further down as I’m using newer versions of AOSP, Gapps & TWRP.

Nov ’20: The screenshot above shows a 5 March 2020 security patch level, but the version of AOSP I recently installed states a 5 September 2020 security level.

Introduction
The Asus Nexus 7 was the first tablet released by Google and I like the hardware. However when Google updated it to Android 5.1.1 it felt sluggish. My fiancée had been using the Nexus 7, but with the slow performance it wasn’t used between 2017 and 2020!

The last official ROM that I installed was LMY47V released in April 2015. So I decided to breath some new life into the old hardware with a change of ROM!

A huge thank you to AndDiSa over at XDA and anyone else involved in creating the Android 7.1.2 custom rom, which not only takes the tablet beyond Android 5 to version 7, but the performance is excellent and my fiancée is now using the tablet daily!

AndDiSa is a fantastic person as not only was a 7.1.2 custom rom released, but at the time of writing this blog post, security patches have recently been released. Incredible work! Thank you.

Warning: You follow my Nexus 7 instructions at your own risk. Please be aware that you could make your tablet unusable and also you need to backup any data you wish to save to another device before you proceed. Existing data on the tablet will be wiped if you follow this ‘how to’ guide.

Please note: With my Nexus 7 running this custom rom I have to hold the power switch for up-to approximately thirty seconds to get it to turn on. The other day I might have accidentally left the tablet on and drained the battery. By placing it on charge for an hour, I was then able to get the tablet to turn on.

How to install a custom rom on a Google Nexus 7 ME370T (2012 Grouper)

Please also note: These instructions cover using Windows 10 as part of the installation process and I’m not providing help for using another operation system.

2nd Warning: Please read the first warning at the top of this blog post and also make sure your Nexus 7 is fully charged before continuing. I also don’t vouch for any files that you download at your own risk.

3rd Warning: You are going to wipe all data on the tablet if you follow these instructions! You are responsible for any problems and costs that result from following these instructions!

November 2020 update: The majority of the instructions below written in May 2020 are still relevant and I’ve left them in place. However I’ve just upgraded another Nexus 7 and there were a few differences, which I will mention in blue below.

Step 1 – Setup the Nexus to work with Windows 10

1. Turn on your Windows 10 PC.
2. On the Nexus 7, please hold the volume down and power buttons until the fastscreen mode is shown.
3. In the bottom area of Windows 10, where it says “Type here to search”, type device manager.
4. Connect the tablet to the PC via a USB cable.
5. If under ‘Other devices’ you see ‘Android’, right click on it, select ‘Properties’ and then ‘Update Driver…’.
6. Select ‘Search automatically for update driver software’. *
7. Hopefully the ‘Android Bootloader Interface’ driver is installed. When ready, click on ‘Close’.

* When I performed the download on my PC, it took a while for the download to complete.

If you run into trouble installing the Android Bootloader Interface, you could try the ‘Universal ADB Drivers’ over at adb.clockworkmod.com

Step 2 – Download and extract the necessary files (written in May 2020)

1. Download the Google ADB and other tools from here and extract the files from the archive.
2. Check at Android 7.1.2 AOSP Grouper for the latest version to download. The version I used can be found here and here. *
3. Download TWRP 3.3.1 Grouper from here or here.
4. Download Gapps ARM 7.1 Pico.
5. Place the TWRP zip file in the same directory as the ADB files.

* Obviously I based my installation instructions on the version I used and so please take that into consideration if installing a later version.

Nov ‘20 update: The Android 7.1.2 AOSP Grouper version I installed in November 2020 is the 11th September 2020 version and you can download it from here or here. The TWRP version I used recently is version 3.4.0.0 which you can download from here or here. I used the 6th November 2020 Gapps ARM 7.1 pico with the 11th Sept ’20 ROM, and the Gapps zip file can be downloaded here.

Step 3 – Unlock the Nexus 7 and install TWRP

3rd Warning: Again please make sure your Nexus 7 is fully charged before proceeding.

1. Make sure the tablet is turned off.
2. On a Windows computer, open a command prompt and then go to the directory where you extracted the Google ADB files to. *
3. On the tablet hold the volume down and power button until the fastscreen mode is shown.
4. Connect the tablet to the computer via a USB cable.
5. If the lock state on the tablet’s screen shows ‘locked’, in a command prompt type fastboot oem unlock
6. You will be prompted to select either ‘Yes’ or ‘No’. Select ‘Yes’ to unlock the Nexus 7.
7. Now type fastboot flash recovery twrp-3.3.1-0-grouper.img
8. Type fastboot reboot and then hold the volume down and power button again to boot into the fastscreen mode. **
9. Use the volume up button to change the option to ‘recovery mode’ and press the power button to boot into TWRP.
10. In TWRP move the arrows to ‘Swipe to Allow Modifications’.

* In are of Windows 10 where it says “Type here to search” you can type command and press enter.

** If you don’t do step 8, 9 and 10, the tablet will boot up and wipe the TWRP installation!

Step 4 – Install Android 7.1 AOSP Grouper and Gapps on the Nexus 7

Nov ‘20 update: The instructions below not in blue were only published in May ’20 and written for older versions of TWRP and ROM. Using TWRP 3.4.0.0, a more recent ROM and Gapps in Nov ’20 on a second 2012 Nexus 7 Grouper, I did things slightly differently:

1. Before the factory reset mentioned below, I did a ‘Format Data’. Then after the factory reset for some reason via ‘Advanced Wipe’, I wiped the ‘Dalvik/ART Cache & Cache’. I doubt it’s worth mentioning this, but I was sleepy, did the additional steps, so mentioned here!
2. If you have trouble moving the zip files across to the Nexus 7 when in TWRP, you could try rebooting into TWRP and then connecting a USB lead.
3. Then after moving the two zip files across, I rebooted the tablet and went back into TWRP. The reboot into recovery (TWRP) got me past an ‘ERROR:7 Error installing zip file’ issue with the September version of AOSP (the custom 7.1.2 ROM).

Everything else I did in Nov ’20 was exactly the same as I did below in May ’20. It’s likely only items two and three above are relevant and I hope this quick update will suffice. I’m not trying out every version of AOSP, so I won’t be trying to keep my instructions up-to-date with all versions.

1. In TWRP select ‘Wipe’ and then afterwards perform a ‘Factory Reset’.
2. After the reset use the back arrows to return to the main menu.
3. With TWRP running, connect your tablet to a Windows 10 PC via a USB cable.
4. Move the AOSP Grouper zip and ARM 7.1 Pico Gapps files across to the Nexus.
5. From the TWRP menu, select ‘Install’.
6. Find the AOSP file you placed on the Nexus, select and then ‘Swipe to confirm Flash’.
7. Select ‘Reboot System’, then reboot into recovery mode, by holding volume down and the power button, then selecting ‘recovery mode’.
8. In TWRP select ‘Install’ and then find and select the Gapps file and then ‘Swipe to confirm Flash’.
9. After the flash find and select ‘Wipe Cache/Dalvik’ and then ‘Swipe to Wipe’.
10. Finally find and select ‘Reboot System’.

November 2020: Please expect the first boot to take approximately five minutes with only the ‘android’ name showing. After that first boot, later boots on my Nexus 7 are a lot quicker.

Q. How do I solve the “The drivers for this device are not installed. (Code 28)” error.
A. On Windows 10 you can try updating the driver via ‘Device Manager’ and hopefully the ‘Search automatically for updated driver software’ option will install the LeMobile Android Bootloader Interface.

Q. How do I close an application on Android 7.1?
A. If the option isn’t shown at the bottom of the screen, move your hand from top to bottom and hopefully three additional buttons appear. Then you can use those options to switch between applications and to close them.

I hope you’ve found my how to instructions useful and I would appreciate a thank you in the comments.