Use NFC on Galaxy Nexus While the Screen is Off or Locked
Near Field Communication (NFC) is available in number of Android devices and Android users are looking for new uses for NFC. With the passage of time, NFC has become a big part of Android tools and you can find number of tools that help NFC users but there’s a problem users are facing, it requires the screen to be on with the app running, it waste the battery life of device. But a recognized XDA developer member Geniusdog254 has developed a MOD for the Galaxy Nexus that allows you to get rid of this issue.
There are three MODs, NFC.apk runs at boot that lets you to scan NFC tags while the screen is complete off, it make NFC experience easier, try it. Another is screen off version that allows you always scan NFC tag, don’t turn the screen on or run anything else, touch the device to tag. The last one is lockscreen that allows you to scan a tag whenever the screen is on but not unlocked, no you can’t scan a tag when the screen is off with this mode but touch the power button to scan.
Follow the below guide to install it but first make sure ClockworkMod recovery is installed on the device, use this toolkit to install ClockworkMod recovery and make a backup of your device data such as SMS, internet setting, contacts music files etc because the below procedure may wipe data, however chances are bit low, but I strongly recommend, you can sync your contacts with Gmail account and for messages use SMS apps, lastly use file expert app to backup apps.
DISCLAIMER: Please proceed the below guide at your own risk, Android Egis will not be held responsible if your device lost data or get damaged following this guide.
Step #1: Download one Mod you want to install NFC.APK, Screen Off or Lockscreen from here [XDA Link].
Step #2: Plug the device to PC using USB cable.
Step #3: Transfer the downloaded file to phone.
Step #4: Disconnect the device from PC.
Step #5: Turn the device off.
Step #6: Reboot the device into recovery mode by holding down power, volume up and volume down buttons, first device will enter int fastboot mode, there select recovery option using volume keys and select it by power button.
Step #7: In recovery mode, create a nandroid backup of your current ROM, it’s important because if anything goes wrong you’ll be able to easily revert back to your current state. To create backup select “Backup and Restore”, and then select “Backup” again.
Step #8: Select Install, then browse and select the file you downloaded in step 1 and confirm installation.
That’s it, you’re done. You can also visit the original thread of XDA link given in first step.