[android-developers] Re: Android USB problems

How do I get an app to read data from a USB barcode reader if the usbManager can't even detect that its there.

On Thursday, September 19, 2013 3:55:19 PM UTC-4, eli wrote:

I have a tablet, an OTG cable and a barcode reader. I know this works because when I start the Google app I can scan barcodes and see them on the screen. I created a very simple application that starts the USB manager and checks how many devices are attached. When I have a memory flash stick in the OTG cable the program shows 1. (correct) When I have a mouse in the OTG cable it shows 0. (why) Interesting observation. When I connect the mouse to the OTG cable it works fine. I use it to click on the button to ask the usbManager how many devices are attached and the response is 0.  When I attach a barcode reader to the OTG cable, the application goes through onDestroy() and then shows 0. (Why does this happen) Basics of my program developed using Eclipse: In onCreate() I have: usbManager = (UsbManager)getSystemService(Context.USB_SERVICE);   In onClick() I have              (there is a button on the screen): Map<String, UsbDevice> usbDeviceList = sbManager.getDeviceList(); Toast.makeText(this, String.format("Number of devices = %d", usbDeviceList.size()), Toast.LENGTH_SHORT).show();

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