node-hid - Access USB HID devices from Node.js
Platform Support
node-hid
supports Node.js v4 and upwards. For versions 0.10 and 0.12,
you will need to build from source. The platforms, architectures and node versions node-hid
supports are the following;
Platform / Arch | Node v4.x | Node v6.x | Node v7.x |
---|
Windows / x86 | ☑ | ☑ | ☑ |
Windows / x64 | ☑ | ☑ | ☑ |
Mac OSX / x64 | ☑ | ☑ | ☑ |
Linux / x64 | ☑ | ☑ | ☑ |
Linux / ia32 | ☐ | ☐ | ☐ |
Linux / ARM v6¹ | ☐ | ☐ | ☐ |
Linux / ARM v7¹ | ☐ | ☐ | ☐ |
Linux / ARM v8¹ | ☐ | ☐ | ☐ |
Linux / MIPSel¹ | ☐ | ☐ | ☐ |
Linux / PPC64¹ | ☐ | ☐ | ☐ |
¹ ia32, ARM, MIPSel and PPC64 platforms are known to work but are not currently part of our test or build matrix. ARM v4 and v5 was dropped from Node.js after Node v0.10.
Installation
For most "standard" use cases (node v4.x on mac, linux, windows on a x86 or x64 processor), node-hid
will install nice and easy with a standard:
npm install node-hid
Installation Special Cases
We are using prebuild to compile and post binaries of the library for most common use cases (linux, mac, windows on standard processor platforms). If you are on a special case, node-hid
will work, but it will compile the binary when you install.
If node-hid
doesn't have a pre-built binary for your system
(e.g. Linux on Raspberry Pi),
node-gyp
is used to compile node-hid
locally. It will need the pre-requisites
listed in Compling from source below.
Examples
In the src/
directory, various JavaScript programs can be found
that talk to specific devices in some way. Some interesting ones:
To try them out, call them like node src/showdevices.js
from the node-hid directory.
Usage
List all HID devices connected
var HID = require('node-hid');
var devices = HID.devices();
devices
will contain an array of objects, one for each HID device
available. Of particular interest are the vendorId
and
productId
, as they uniquely identify a device, and the
path
, which is needed to open a particular device.
Sample output:
HID.devices();
[ { vendorId: 1452,
productId: 595,
path: 'USB_05ac_0253_0x100a148e0',
serialNumber: '',
manufacturer: 'Apple Inc.',
product: 'Apple Internal Keyboard / Trackpad',
release: 280,
interface: -1 },
{ vendorId: 1452,
productId: 595,
path: 'USB_05ac_0253_0x100a14e20',
serialNumber: '',
manufacturer: 'Apple Inc.',
product: 'Apple Internal Keyboard / Trackpad',
release: 280,
interface: -1 },
<and more>
Opening a device
Before a device can be read from or written to, it must be opened.
The path
can be determined by a prior HID.devices() call.
Use either the path
from the list returned by a prior call to HID.devices()
:
var device = new HID.HID(path);
or open the first device matching a VID/PID pair:
var device = new HID.HID(vid,pid);
The device
variable will contain a handle to the device.
If an error occurs opening the device, an exception will be thrown.
Reading from a device
A node-hid
device is an EventEmitter.
Reading from a device is performed by registering a "data" event handler:
device.on("data", function(data) {});
You can also listen for errors like this:
device.on("error", function(err) {});
Notes:
- All reading is asynchronous
- The
data
event receives INPUT reports. To receive Feature reports,
see the readFeatureReport()
method below. - To remove an event handler, close the device with
device.close()
Writing to a device
Writing to a device is performed using the write call in a device
handle. All writing is synchronous.
device.write([0x00, 0x01, 0x01, 0x05, 0xff, 0xff]);
Notes:
- The
write()
method sends OUTPUT reports. To send Feature reports,
see the sendFeatureReport()
method below. - Some devices use reportIds for OUTPUT reports. If that is the case,
the first byte of the array to
write()
should be the reportId. - BUG: if the first byte of a
write()
is 0x00, you may need to prepend an extra 0x00 due to a bug in hidapi (see issue #187)
Complete API
devices = HID.devices()
- Return array listing all connected HID devices
device = new HID.HID(path)
- Open a HID device at the specifed platform-speific path
device = new HID.HID(vid,pid)
- Open first HID device with speciic VendorId and ProductId
device.on('data', function(data) {} )
data
- Buffer - the data read from the device
device.on('error, function(error) {} )
error
- The error Object emitted
device.write(data)
data
- the data to be synchronously written to the device
device.close()
Closes the device. Subsequent reads will raise an error.
device.pause()
Pauses reading and the emission of data
events.
device.resume()
This method will cause the HID device to resume emmitting data
events.
If no listeners are registered for the data
event, data will be lost.
When a data
event is registered for this HID device, this method will
be automatically called.
device.read(callback)
Low-level function call to initiate an asynchronous read from the device.
callback
is of the form callback(err, data)
device.readSync()
Return an array of numbers data. If an error occurs, an exception will be thrown.
device.readTimeout(time_out)
time_out
- timeout in milliseconds
Return an array of numbers data. If an error occurs, an exception will be thrown.
device.sendFeatureReport(data)
data
- data of HID feature report, with 0th byte being report_id ([report_id,...]
)
device.getFeatureReport(report_id, report_length)
report_id
- HID feature report id to getreport_length
- length of report
Notes for Specific Devices
- Xbox 360 Controller on Windows 10 -- does not work
Linux-specific Notes
usage
and usagePage
device info fields
These are not available on Linux, only Mac and Windows.
For reason why, and to ask for its addition, see:
https://github.com/signal11/hidapi/pull/6
hidraw support
To install node-hid with the hidraw
driver instead of the default libusb one,
install the "libudev-dev" package and rebuild the library with:
npm install node-hid --driver=hidraw
udev device permissions
Most Linux distros use udev
to manage access to physical devices,
and USB HID devices are normally owned by the root
user.
To allow non-root access, you must create a udev rule for the device,
based on the devices vendorId and productId.
This rule is a file, placed in /etc/udev/rules.d
, with the lines:
SUBSYSTEM=="input", GROUP="input", MODE="0666"
SUBSYSTEM=="usb", ATTRS{idVendor}=="27b8", ATTRS{idProduct}=="01ed", MODE:="666", GROUP="plugdev"
(the above is for vendorId = 27b8, productId = 01ed)
Then the udev service is reloaded with: sudo udevadm control --reload-rules
For an example, see the
blink1 udev rules.
Compiling from source
To compile & develop locally or if prebuild
cannot download a pre-built
binary for you, you will need the following tools:
To build node-hid
from source for your project:
npm install node-hid --build-from-source
To build node-hid
for development:
- check out a copy of this repo
- change into its directory
- update the submodules
- build the node package
For example:
git clone https://github.com/node-hid/node-hid.git
cd node-hid # must change into node-hid directory
npm install --build-from-source # rebuilds the module with C code
node ./src/show-devices.js
You will likely see some warnings from the C compiler as it compiles
hidapi (the underlying C library node-hid
uses).
This is expected.
Using node-hid
in Electron projects
In your electron project, add electron-rebuild
and electron-prebuilt
to your devDependencies
.
Then in your package.json scripts
add:
"postinstall": "electron-rebuild --force"
If you want a specific version of electron, do something like:
electron-rebuild -v 0.36.5 --force -m . -w node-hid
Using node-hid
in NW.js projects
(TBD)
Support
Please use the node-hid github issues page
for support questions and issues.