B4A Library UsbSerial library 2.0 - supports more devices

This is an expanded version of the original UsbSerial library. It has added support for Prolific PL2303 USB to serial converters, Android ADK devices and USB permissions. All devices use the same simple interface intended to be used with AsyncStreams and AsyncStreamsText. Note that AsyncStreams prefix mode is not supported. The library is based on the same open source project Android USB host serial driver library as the existing UsbSerial library but no longer needs a separate jar file as the project source code is incorporated in the library.

The specific enhancements to the library over the original UsbSerial library are :

UsbPresent, HasPermission and RequestPermission are added to identify any attached device or Accessory available to the library and deal with permission to access it.

SetParameters, which must be used after Open(), and the constants for SetParameters provides acess to all the serial line parameters instead of just baud rate.

DeviceInfo provides a string containing information about a device. This works for slave devices only.

Android Accessories, which are host mode devices, are recognised and can be used in the same way as the other slave mode devices.

Prolific PL2303 support is added.

Silicon Labs CP210x support is added - maybe only the CP2102 as I have no hardware to test.

The FTDI "status byte" bug on reading input that existed in version 1.0 of this library is hopefully fixed.


The usb-serial-for-android project and therefore also this library is licensed under the GNU Lesser General Public License v3. http://www.gnu.org/licenses/lgpl.html|http://www.gnu.org/licenses/lgpl.html
Copies of both the General Public License and Lesser General Public License are in the provided archive.

The user has to give your application permission to access the USB device before it can be opened. You can do this in two ways.

As with the original UsbSerial library you can add the following code to the manifest editor

AddActivityText(main, <intent-filter>
        <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
    </intent-filter>
    <meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"
        android:resource="@xml/device_filter" />)

Then copy device_filter.xml from the demo in the attached archive to: <your project>\objects\res\xml and mark it as read-only. Note that this is an expanded version of the original device_filter.xml file.

Finally install the program and attach the USB device. A dialog will appear asking whether you want to start your program. If you check the “Use by default…” checkbox from now on when the USB device is plugged in your program will be started. If you don’t check the checkbox then you will be asked each time the device is plugged in.

A similar procedure can be used for Accessories as detailed in the “Using an intent filter” section here USB Accessory | Android Developers


Alternatively you can use the new HasPermission and RequestPermission methods without requiring any of the above steps. The demo in the archive incorporates both ways of obtaining permission.

EDIT:- Version 2.1 now posted. See post #4 for details

EDIT:- Version 2.2 now posted. See post #14 for details

EDIT:- Version 2.3 now posted. See post #26 for details

V2.4 is available here: http://www.b4x.com/android/forum/th...pports-more-devices.28176/page-11#post-259167
This update adds support for devices connected to multiple USB adapters.

V2.5 is available as an attachment to this post. It is identical to version 2.4 referenced above but adds the required flag for Pending Intents when targeting SDK 31+.

V2.6 is available as an attachment to this post. It is identical to version 2.5 referenced above but adds the required flag for Pending Intents when targeting SDK 34+.

 

[yo3ggx]

For reference: "Serial USB terminal" app has such devices filter:

I don't think that all of the devices from this list are supported by the USB Serial Library?
Is device filter relevant or required if you don't want to automatically start your app when a specific device is connected?

Dan

 

[MarcoRome]

Hi @agraham and thank you for this library.
I am using version 2.50 on an Android 14 device.
In manifest i have: android:targetSdkVersion="34"

With the following code:

If usb.UsbPresent(1) = usb.USB_NONE Then    ' Ver_2.4
        Log("No device USB NONE")
        Return
    End If
    If (usb.HasPermission(1)) Then    ' Ver_2.4
              Log("Device Information USB" & CRLF & usb.DeviceInfo(1))
    Else
            Log("Error opening USB port 1")
            Log("**************" & CRLF & "ERROR OPENING USB PORT 1 STEP 2" &CRLF& "**************")
    End If
    Else
        usb.RequestPermission(1)  ' Ver_2.4
    End If

it gives me the following error:

java.lang.IllegalArgumentException: arduino.demo.com: Targeting U+ (version 34 and above) disallows creating or retrieving a PendingIntent with FLAG_MUTABLE, an implicit Intent within and without FLAG_NO_CREATE and FLAG_ALLOW_UNSAFE_IMPLICIT_INTENT for security reasons. To retrieve an already existing PendingIntent, use FLAG_NO_CREATE, however, to create a new PendingIntent with an implicit Intent use FLAG_IMMUTABLE.

Note: If I change Manifest to 33 everything works

 

[agraham]

Try this and post if it works or not

 

[MarcoRome]

Try this and post if it works or not

Great @agraham
Work with out problem