Node.JS library for communicating with USB devices in JavaScript / CoffeeScript.
This is a refactoring / rewrite of Christopher Klein's node-usb. The API is not compatible (hopefully you find it an improvement).
It's based entirely on libusb's asynchronous API for better efficiency, and provides a stream API for continuously streaming data or events.
Tested with Node 0.6.12/Linux and 0.8.14/Linux.
Older versions of libusb segfault when using bulk or interrupt endpoints. Use libusb or libusbx 1.0.9 or greater.
Make sure you have installed libusb-1.0-0-dev (Ubuntu: sudo apt-get install libusb-1.0-0-dev).
Just run
npm install usb
to install from npm. See the bottom of this page for instructions for building from a git checkout.
var usb = require('usb')
Top-level object.
List of Device objects for the USB devices attached to the system.
Constant properties from libusb
Set the libusb debug level (between 0 and 4)
Represents a USB device.
Perform a control transfer with libusb_control_transfer.
Parameter data_or_length can be a integer length for an IN transfer, or a Buffer for an out transfer. The type must match the direction specified in the MSB of bmRequestType.
The data parameter of the callback is always undefined for OUT transfers, or will be passed a Buffer for IN transfers.
Return the interface with the specified index and alternate setting.
List of Interface objects for the interfaces of the default configuration of the device.
(property getter/setter) Timeout in milliseconds to use for controlTransfer and endpoint transfers.
Integer USB device address
Integer USB device number
Performs a reset of the device. Callback is called when complete.
Object with properties for the fields of the device descriptor:
- bLength
- bDescriptorType
- bcdUSB
- bDeviceClass
- bDeviceSubClass
- bDeviceProtocol
- bMaxPacketSize0
- idVendor
- idProduct
- bcdDevice
- iManufacturer
- iProduct
- iSerialNumber
- bNumConfigurations
Object with properties for the fields of the config descriptor:
- bLength
- bDescriptorType
- wTotalLength
- bNumInterfaces
- bConfigurationValue
- iConfiguration
- bmAttributes
- MaxPower
- extra: Buffer containing additional data
Return the InEndpoint or OutEndpoint with the specified address.
List of endpoints on this interface: InEndpoint and OutEndpoint objects.
Integer interface number.
Integer alternate setting number.
Claims the interface. This method must be called before using any endpoints of this interface.
Releases the interface and resets the alternate setting. Calls callback when complete.
Detaches the kernel driver from interface.
Re-attaches the kernel driver to interface.
Returns 0 if not active; 1 if active.
Fields from the interface descriptor, see libusb documentation or USB spec.
- bLength
- bDescriptorType
- bInterfaceNumber
- bAlternateSetting
- bNumEndpoints
- bInterfaceClass
- bInterfaceSubClass
- bInterfaceProtocol
- iInterface
- extraData : Buffer
Common base for InEndpoint and OutEndpoint, see below.
Endpoint direction: usb.LIBUSB_ENDPOINT_IN or usb.LIBUSB_ENDPOINT_OUT.
Endpoint type: usb.LIBUSB_TRANSFER_BULK, usb.LIBUSB_TRANSFER_INTERRUPT, or usb.LIBUSB_TRANSFER_ISOCHRONOUS.
The max packet size.
The max isochronous packet size if transfer type is isochronous.
Fields from the interface descriptor, see libusb documentation or USB spec.
- bLength
- bDescriptorType
- bEndpointAddress
- bmAttributes
- wMaxPacketSize
- bInterval
- bRefresh
- bSynchAddress
- extra_length
- extraData : Buffer
Endpoints in the IN direction (device->PC) have this type.
Perform a transfer to read data from the endpoint.
If length is greater than maxPacketSize, libusb will automatically split the transfer in multiple packets, and you will receive one callback with all data once all packets are complete.
this in the callback is the InEndpoint object.
Start a streaming transfer from the endpoint.
The library will keep nTransfers
transfers of size transferSize pending in the kernel at all times to ensure
continuous data flow. This is handled by the libusb event thread, so it continues even
if the Node v8 thread is busy. The data and error events are emitted as transfers complete.
Stop the streaming transfer.
Further data may still be received. The end event is emitted once all transfers have completed or canceled.
Emitted with data received by the stream
Emitted when the stream encounters an error.
Emitted when the stream has been canceled
Endpoints in the OUT direction (PC->device) have this type.
Perform a transfer to write data to the endpoint.
If length is greater than maxPacketSize, libusb will automatically split the transfer in multiple packets, and you will receive one callback once all packets are complete.
Callback first parameter is data, just like InEndpoint, but will always be undefined as no data is returned.
this in the callback is the OutEndpoint object.
Start a streaming transfer to the endpoint.
The library will help you maintain nTransfers transfers pending in the kernel to ensure continuous data flow.
The drain event is emitted when another transfer is necessary. Your drain handler should use the .write() method
to start another transfer.
Write data to the endpoint with the stream. data should be a buffer of length transferSize as passed to startStream.
Delegates to .transfer(), but differs in that it updates the stream state tracking the number of requests in flight.
Stop the streaming transfer.
No further drain events will be emitted. When all transfers have been completed, the OutEndpoint emits the end event.
Emitted when the stream requests more data. Use the .write() method to start another transfer.
Emitted when the stream encounters an error.
Emitted when the stream has been stopped and all pending requests have been completed.
To build from git:
git clone https://github.com/nonolith/node-usb.git cd node-usb npm install
To execute the unit tests, CoffeeScript is required. Run
npm test
Some tests require an attached USB device -- firmware to be released soon.
Does not support:
- Configurations other than the default one
- Isochronous transfers