Pairing issue when using SingleEntry (Android)

Question

Socket Mobile SDK documentation states that the socket mobile scanner must be in "SPP" mode in order to work with the SingleEntry example. However, it seems that none of the Android phones i've tested recognize the device when in this mode for initial pairing. It does display in the paired devices list, connects to it fine, but does not fire any of the events (OnDeviceArrival, OnDecodedData, etc..) when a scan happens.

I can only get the SingleEntry example app to work with my Socket Mobile S800 by following the below steps (exactly):

1. Make sure scanner is in HID mode (default)
2. On my Android device, scan for pair-able devices. (the S800 displays with a keyboard icon)
3. Select the S800 device. (S800 does beep confirmation on connection)
4. Once the device is paired, un-pair it.
5. Change the S800 mode to "SPP" by scanning the appropriate code (recommended mode to work with Xamarin SingleEntry example)
6. Re-pair with the S800 device on my Android phone. (the S800 icon is now a desktop instead of a keyboard)
7. Open the "Socket EZ Pair" app, select pair using Bluetooth, select my S800 device from the list.
8. Now the OnDecodedData callback fires in the SingleEntry project.

What is the "Socket EZ Pair" app doing that i should be doing in my code to properly pair the device when in "SPP" mode?

Are there any better solutions for cross platform Bluetooth scanning? I'm particularly interested in just the OnScan (OnDecodedData) events...

Answer 1

UPDATE

The explanation is actually very simple. The SingleEntry Xamarin.Android app doesn't handle configuring the scanner for ScanAPI.

As you noted, after pairing the scanner you need to use EZ Pair before the scanner will be recognized by your app. This is because when you pair the scanner using Bluetooth settings, it creates an outgoing connection to the scanner, but ScanAPI listens for incoming connections. EZ Pair presents you with a list of paired Bluetooth devices, it connects to the one you select and configures that scanner to connect back before closing the connection.

The SingleEntry Android sample application includes the EZ Pair logic, but the Xamarin sample does not.

However, once you've used EZ Pair to configure your scanner to connect back, you should receive device arrival and decoded data notifications in the unmodified SingleEntry Xamarin.Android sample application.

Original answer

Not the solution, but good to check

Runtime permissions were introduced in Android 6.0 and SingleEntry has not been updated to check for the required permissions. Unfortunately, the file that sets the target framework is not checked in to git so fresh clones of the sample app now target newer versions than SingleEntry was designed for.

If you open Settings > Apps > Single Entry > Permissions and enable the storage permission, then it should start working.

The real fix is to check for WRITE_EXTERNAL_STORAGE and BLUETOOTH permissions before calling ScanApiHelper.Open() in your application.