RxUsb

High level cross-platform usb library built with Kotlin with reactive streams.

LIBRARY IS UNDER DEVELOPMENT AND MAY LACK SOME IMPORTANT FEATURES. Currently it can be used primarily for reading data from usb bulk transfers.

How to use

Library setup

Add custom maven repository

repositories {
    mavenCentral()
    maven {
        url 'https://packages.eraga.net/repository/eraga-public-maven-releases/'
    }
}

Dependency for Desktop apps:

compile "net.eraga.rxusb:libusb:1.0.5"

Dependency for Android apps (libusb):

compile "net.eraga.rxusb:libusb-android:1.0.5"

Usage

List all connected USB devices:

val usbManager = UsbService.instance

usbManager.getDeviceList().forEach {
    println(it)
}

Subscribe to bulk transfers' content and print it to stdout as soon as it comes with the power of rxjava2:

val usbManager = UsbService.instance

val device = usbManager.findDevice(0x1a86, 0x7523)

val deviceConnection = usbManager.openDevice(device)

val interfaceConnection = deviceConnection.claimInterface(device.getInterface(0))

val bulkEndpoint = interfaceConnection.open(
        interfaceConnection.usbInterface.getEndpoint(0)
) as BulkReadableChannel

bulkEndpoint.subscribeOn(Schedulers.io())
        .map<String> { byteArray ->
            // Lets think that this usb device sends UTF-8 text
            byteArray.toString(Charsets.UTF_8)
        }
        .observeOn(Schedulers.single())
        .subscribe({ text ->
            // output incoming text
            println(text)
        })

Share bulk transfer data between two different parts of code and treat it differentely:

val sharedEndpoint = bulkEndpoint.share()

sharedEndpoint
        .subscribeOn(Schedulers.io())
        .subscribe {
    // do some incredible stuff
}

sharedEndpoint
        .subscribeOn(Schedulers.io())
        .subscribe {
    // do some other stuff
}

Send data to USB device:

val bulkOutEndpoint = interfaceConnection.open(
        interfaceConnection.usbInterface.getEndpoint(1)
) as BulkWritableChannel

val text = "Hello World!"

val textByteBuffer = ByteBuffer.allocateDirect(text.length)
textByteBuffer.put(text.toByteArray())

bulkOutEndpoint.send(textByteBuffer)
        .subscribe ({
            log.info("Data successfully sent")
        },{
            log.error("Error: {}", it)
        })