A reader asked if there is a way to determine the status of the Android device battery in MIT App Inventor. Unfortunately, App Inventor does not provide a way to check the battery status … but Appy Builder does!
To answer that question, our first Appy Builder app is a simple tutorial showing how to use the BatteryStatus component in Appy Builder.
The output is displayed after pressing the Start button and shows that my phone’s battery is at 99% and was plugged in to the AC power charger.
In this screen shot, the phone was unplugged from the battery charger and the “plugged in” status has changed to UNKNOWN.
I created this screen by adding a Button control, and then adding six HorizontalLayouts. Inside each layout, I dragged two Label controls, setting one to the descriptive text (such as “Battery level:” and the second to be used to display the status for that property).
The BatteryManager has several properties that describe aspects of the battery.
Before the properties may be used you must activate the BatteryManager by setting the .StartMonitoring property to true; this must be done separately as shown below. Errors occurred when I put that code inside the button’s .Click handler. Instead, I moved the StartMonitoring assignment to the Screen1.Initialize event handler and everything worked fine.
- BatteryLevel – the battery’s current level in percent
- BatteryTemperature – the temperature of the battery in degrees Celsius
- BatteryPresent – true (my phone does not permit me to remove the battery)
- BatteryPlugged – returns “AC” if the device is connected to a charger, or UNKNOWN if the device is not plugged in. This might also return “WIRELESS” if the device is currently using a wireless charger (based on Android BatteryManager API).
- BatteryVoltage – battery voltage. A typically value will be near 4 volts plus or minus for most phones.
- BatteryHealth – GOOD. I presume this returns a value corresponding to the Android BatteryManager API, which includes COLD, DEAD, GOOD, OVERHEAT, OVER_VOLTAGE, UNKNOWN and UNSPECIFIED_FAILURE.
Right-click (or Ctrl-click on Mac OS X) and use your browser’s feature to save this file to your computer: BatteryStatus.aia
Then, use Projects | Import selected project (.aia) from my computer … to load the file into Appy Builder