Android 4.4.2 LCD Panel Update Issues


Last Update: Jan 2, 2022 @ 09:55 Preliminary information, subject to change.

This is an Application Note that investigates if it is possible to update an industrial-grade Android 4.4.2 development panel to a much newer Android version. Also to be investigated is whether a native install of Ubuntu Desktop is possible.

Android 4 panel browser displaying the PiXCL website, repeated to the 1920×1080 screen
via the HDMI connector on the right side. Panel is 1024×600 pixels. USB devices on the panel
top edge are a Realtek WiFi network interface and wireless mouse dongle.

The 2017-manufacture panel was supplied with Android 4.4.2, and consists of a 1.4GHz quad core ARM Cortex-A9, 1GB ram, wired or WiFi networking, and with a 1024×600 touch screen. Four USB2 ports plus Bluetooth are included.

Does the panel work ?

Yes, it does. The main issue is that the current just released Android version is 12, and while many Google Store apps require at least Android 6, more require Android 9+. In addition, the linux kernel version changes with the newer Android versions.

The default set of apps plus three side-loaded apps (Network Speed Test, NetX Tools and USB Info).

We tried loading some simple apps from the Play Store, but it proved next to impossible because we could not load a newer version of Chrome to enable a successful login. Fortunately there is a solution called Side Loading.

Setting up the panel for Side Loading and Development

The panel has a USB (OTG) port which when connected to a Windows 10 PC appears as a Portable Device, in effect a disk drive. The panel’s set of internal directories and files is available, as listed below.

  • AOSPon drone2
    • internal storage
      • Alarms
      • Android
      • DCIM
      • Download
      • Pictures
        • Screenshots
      • and several others not relevent for this note at present

The Download directory is the important one. This is where app .APK binary files are placed. e.g.

APK files side loaded, as located by the Android File Explorer app. Note that the Android Downloads app places binaries from the Play Store in another location.

Finding and loading APK binaries

The aim here is to find some simple apps that

  • are supported by Android 4 and later
  • are APK, not XAPK, binaries (which can be handled with another app)
  • can be parsed successfully by the Android 4 App Installer.
  • run without displaying a “App Unfortunately Stopped” message.

Loading an APK stored in the Download directory is done via the File Explorer app and Browse/APKs directory. The selected APK can be installed. If the APK can be parsed successfully, the app will probably run.

The network Speed Test app is a useful utility that tests most of the panel hardware.

Why some apps tested would not parse i.e. failed the first install check is unclear, and will be investigated.

Apps that “Unfortunately Stop” may be caused by an incompatibility with the panel hardware (e.g. a lack of resources), the 4.4.2 version, a bug in the app, or a combination of all three.

What is the current Android firmware status

Selecting the Settings–>About tablet menu displays the following.

Android version 4.4.2, kernel version 3.4.39, 8GB storage, 1GB ram.

The hardware is likely capable of running a newer Android version. The manufacturer used to offer an Android 5 update, but this is no longer available. At present, Android 4.4.2 is installed with the 3.4.39 linux kernel that was first released with Android 4.3.

A full update would require the matched set of kernel and Android files.

Still to be investigated: Is is possible to install the Ubuntu 20.04 Desktop on to the panel hardware. Put another way, for the panel to be usable, an Android upgrade is not essential, and a native install of Ubuntu would be just as useful. Research indicates that there are ways to create a “sandbox” Android app that runs Ubuntu, but all information found suggests that a newer Android (say, minimum 10) is required.

Does the panel need to be rooted?

Unknown as yet.

Side Loading oddities found with this panel

< more to add >