Nexus 7

From Wildsong Wiki
Revision as of 21:26, 23 October 2016 by Brian Wilson (Talk | contribs)

Jump to: navigation, search

Code name for the GSM Nexus 7 is Tilapia.



ASUS Nexus 7 2012

  • Tegra 3 quad core processor
  • 1 GB RAM
  • 16 GB flash
  • Broadcom BCM4751 GPS chip
  • There are gyro and accelerometer sensors
  • The Tilapia version has a GSM chip, too. Not sure if it works in CyanogenMod
  • WLAN 802.11 b/g/[email protected]
  • NFC chip
  • Bluetooth including BLE support if you run CM10.2 or newer

See teardown at

CM12 try again

2016-08-10 I try CM12 again. SO FAR IT'S WORKING. SO FAR... still working 2016-10-22

CM12.1 fail

2015-Dec-23 Merry X-mas and it's time to try CM12.1 (Android 5.1) WHOOO it's BAD this time. Trebuchet and Messaging crash instantly. I managed to get it running by pulling down from the top to get into settings then clearing the data from Trebuchet and Messaging and Clock. I was also able to get USB debugging turned on in there. Remind me to leave it ON so that I can take control via adb.

Now Google Play Service crashes. Dropping back to CM11 once again. Insert Bad Words here. Oh well.

CM11 is back and working again.

Trying CM11 with OpenGapps 4.4 Nano. Small blessing there.

adb push /sdcard/
adb reboot recovery

Then follow onscreen instructions.

CM12 fail


CM12 is still not stable. Pity, I was getting used to it. The Nexus 7 runs about 10-15 minutes then reboots. I am dropping back to CM 10.2.1 (latest "stable") release. I have been pleased with the results of not using Google Apps though.

My current list of installed apps:

Download from F-Droid

  • Fennec FDroid (Firefox variant)
  • K-9 Mail
  • MyOwnNotes (notebook app running on ownCloud)
  • OpenDocument Reader
  • ownCloud (replacement for Dropbox)
  • Squeezer (Logitech Squeezebox client)
  • Twidere (Twitter client)

Download from

  • Bluetooth File Transfer it.medival.blueftp
  • Mapquest
  • Overdrive (works for checked out library books and for personal ebooks)
  • Skype


I left out the NFC clients this time -- I use the phone for that. I left out Sensorium because it runs all the time in background. If I get around to playing with the bluetooth GPS I will reinstall the app for it.


About a month ago I removed CyanogenMod 10 and installed the latest Google image (Lollypop aka 5.1). Lollypop is so-so, nothing strikingly different, but the battery now runs down every day, and things that used to work fine (like the browser) are now painfully slow.

I suspect the battery problem might be due to running a SIP application that keeps the WiFi lit up all the time, I can uninstall that, but it won't fix the speed issue.

So I am loading CyanogenMod back in. I tried CM12 around Dec 2014 and it was awful... I guess I will try again. I did recover the Nexus 7, see "Bricked Nexus 7" below. Yes CM12 WORKS NOW! And it's snappy!

Ditching Google Apps

With CyanogenMod installed, do I really really have to install Google Apps? Please say no! The biggie is that I lose the "Play Store". I don't DO much with the tablet these days anyway other than read web pages.

Plan A - work around Play Store to get the apps I want.

or Plan B - do what this guy suggests -

Cyanogenmod on the Nexus 7

The instructions for my Nexus 7 "Tilapia" are here:

For some reason the three button boot to get into the Recovery mode usually fails for me. I can pick "reboot" from the power button and then press the volume keys and I get there.

I am trying to install tried CM12 using sideloading. Having successfully transferred the file to the tablet, I am waiting patiently. It says:

detected filesystem ext4 for /dev/block/platform/sdhci-tegra.4/by-name/APP
Patching system image unconditionally
detected filesystem ext4 for /dev/block/platform/sdhci-tegra.4/by-name/APP

I wonder how long this takes... OH. It says "you can tell it's complete if you have regained control over the menu." and I have! Rebooting... it says "Google". Ahhhh it's booting CM12!! Ohhhhh!!! Now it's doing that "optimizing apps" thing. Hope it works better this time! Recovery from the bad version was painful.

Living without Google, Plan A

These are roughly organized in the order that I installed them.

Browse to and download their APK. Enable APK's from Unknown Sources (scary!!!) and install f-droid.apk Open it.

Now use the F-Droid app to install these:

  • Fennec FDroid will replace Firefox. (It's a Firefox version with security tightened up.)
  • BlueGps -- to get GPS from Bluetooth
  • Squeezer -- to control our Logitech Squeezebox
  • NFC Reader -- to read any NFC tags. Just gives tag info, nothing fancy.
  • FareBot reads transport NFC cards. Cool it reads my Clipper!! I will put this on my phone, too.
  • Sensorium - reads sensor data. Note: Runs at startup Great way to see what your tablet sees, and why is that darn GPS turned on again?

Apps in the "Play Store" that are not available in F-Droid can be gotten via if you know the right name. (Copy it from the URL in Google Play Store)

  • Overdrive Media --
  • Bluetooth File Transfer -- so I can copy and post screenshots (Ad suppported)
  • MapQuest - Turn off "Share Additional Information"
  • Skype -

I need lots of MAPS, so I am looking at OpenScienceMap, because it is built on OpenStreetMap and it's using vector tiles. Download the APK directly from their site: Because it's based on OSM, it has the edits I did a couple weeks ago. APPROVED.


  • Barcode Scanner -- (that's the app name) does not work, the camera can't focus close enough.
  • Mifare Classic Tool -- only reads "Mifare Classic" cards - won't read my Clipper card.
  • NFCard -- does not show card info! FAIL!

How can I grab screenshots?

Press power button. There SHOULD be an option there to take a screenshot. If not, go to Settings->Buttons->Power button and you should be able to enable it there.

Once you have a screenshot, it will be saved on the tablet in /Pictures/Screenshots. How do you get it onto your Mac???

  1. Pair the tablet and the Mac.
  2. Install Bluetooth File Transfer and run it. Let it open port 30.
  3. On the Mac, in the Bluetooth icon in the menu bar, select "Browse Files on Device" and select Nexus 7. A dialog will open.
  4. Now you should be able to navigate to the Screenshots folder and pull your file across.
  5. Once you have the file, shut down Bluetooth File Transfer on the tablet by using the "Back" button and selecting "Just Close".

Installing Google Apps later

About an hour after installing CM10, I discovered that there was no Play Store. At that time I was not willing to devote the energy to figure out how to install apps without it, so I relented and installed Google Apps.

Go to the link about to find the Google Apps zip file, and download it to your computer. (I use a Linux virtual machine on a Mac).

On the tablet, I booted into the ClockworkMod by opening a terminal window and typing these commands. You can do the same from the computer using fastboot.

reboot recovery

Then I was able to use this to copy the zip up to the tablet

adb push /sdcard/

Do NOT leave off the last /, else you will remove the symbolic link and replace /sdcard with your zip file. This gives you shell access so you can fix things like this...

adb shell 

Then I used Clockwork to install it.

Bricked Nexus 7

  1. Tried to install CM12. Continuous crashes of Trebuchet, Google Services, Google Play Store, Messaging.
  2. Powered down.
  3. Black screen. Won't start.

I found I could hold down power button for a LONG time and it would boot. I can't get into recovery mode from the device and when I boot into CM12, where once again my apps just crash over and over.

I think I might be able to connect via ADB.

Copying map files for c:geo

  1. Download from
  2. Plug in and detect Nexus, you should see it with "adb devices"
  3. Explore "adb shell" and make a directory to hold the maps. "mkdir /sdcard/osmmaps/"
  4. Copy with adb push /sdcard/osmmaps/

Switching to Ubuntu

Each time I try, Ubuntu is better and there are more reasons to switch. I tried 3 times. There are still no apps.

I am keeping my files here: Projects/UbuntuTouch

Ubuntu Tablet Install

To make Ubuntu Touch development easier I have already switched my desktop to run Ubuntu instead of Mint.

sudo add-apt-repository ppa:phablet-team/tools
sudo apt-get update
sudo apt-get install phablet-tools android-tools-adb android-tools-fastboot
sudo apt-get upgrade

Make a backup

This apparently works to back up my data. Anyway a "full backup" screen came up on the Nexus, and it took a long time.

adb backup -shared
Android 4.2.2
Baseband 1231_0.17.0_1205
Kernel version 3.1.10-g05b777c
Build JDQ39

Download and save a copy of the stock image from Google. NakasiG Nexus 7 Mobile 32 GB

Download Ubuntu image from I found the names of the devices by looking on the site, I have a Tilapia. Maybe I will try a different version of Android soon. There is no Tilapia Ubuntu build so I am using Grouper

-rw-rw-r-- 1 bwilson bwilson 33964483 Nov 17 10:02
-rw-rw-r-- 1 bwilson bwilson  5304320 Nov 17 09:05 saucy-preinstalled-boot-armel+grouper.img
-rw-rw-r-- 1 bwilson bwilson  7288832 Nov 17 10:02 saucy-preinstalled-recovery-armel+grouper.img
-rw-rw-r-- 1 bwilson bwilson 69844256 Nov 17 09:05 saucy-preinstalled-system-armel+grouper.img

See also

  • maguro = Google Galaxy Nexus
  • tilapia = Google Nexus 7 (GSM)