discover method doesn't always return connected printer on Android.

[fragilehm]

I am running the app on Android 11, with Epson TM-m30II Bluetooth printer connected (paired) but in the react-native app, the discover method is inconsistent, it doesn't always find a printer. Like if I put a reload button which calls the discover method it is not always returning the paired printer. Is it a known issue? (couldn't find anything related in https://github.com/tr3v3r/react-native-esc-pos-printer/issues).

[tr3v3r]

@fragilehm hello! Does behavior the same for other OS versions? What do you mean by “not always”? Could you please describe a bit in details please?

BTW you don’t need to pair device before discover. Try to disconnect it from device itself and retry discover.

[fragilehm]

Thanks @tr3v3r for the quick reply, as you can see on the attached gif when I press the reload button discover method is called and it returns the printer but sometimes it doesn't (tried unpairing the printer, getting the same behavior)

Screen.Recording.2021-11-15.at.20.27.32.mov

On iOS it always returns the printer.

[tr3v3r]

@fragilehm what about versions below 11?

As an option we can increase discovery time timeout. For now I stop it manually after 5 sec. you can try to change it here, re-run Android build and test.

react-native-esc-pos-printer/android/src/main/java/com/reactnativeescposprinter/EscPosPrinterDiscoveryModule.java

Line 193 in 0eea276

handler.postDelayed(r, 5000);

[fragilehm]

@tr3v3r didn't try on android 10, but most of your customers are on 11. I tried putting a higher number there like 10 seconds the printer is always returned. I see iOS also has the timeout 5 * NSEC_PER_SEC, but at least from what I was testing it always returns the printer. So maybe it makes sense to allow passing the params in the discover method to set the scanningTimeout for Android and iOS separately? I can make a PR if you think that this is reasonable.

[tr3v3r]

@fragilehm I’d really appreciate it if you could add this possibility to pass timeout param!

[fragilehm]

@tr3v3r can you please review #37

[fragilehm]

Closing the issue as #37 addressed it with increasing the timeout for Android.