README

nodeusbscale

Node.js+Linux (HID) bindings for several USB scales (Pitney Bowes, Dymo, etc.)

Tested with:

0922:8004 Dymo-CoStar Corp.
0d8f:0200 Pitney Bowes

Data packets are in the following format:

{
    'weight': xxxxxx,
    'balanced': <true/false>
}

Example

#!/usr/bin/env node

var UsbScale = require('nodeusbscale');

var dev = UsbScale.create();
dev.open( '/dev/usb/hiddev0', function(obj, err) {
    if( err ) {
        console.log("UsbScale: Failed to open device: "+err);
        return false;
    }
    dev['data'] = function(data) {
        console.log("UsbScale event: "+JSON.stringify(data, null, 2));
    };
});

// Hack to prevent Node.js from exiting, sorry.
var http = require('http');
var httpServer = http.createServer(function(){});
httpServer.listen(8084);
console.log("Listening for keyboard input...");

Methods

Factory

usbscale::create()

Returns an initialised usbscale object.

Returns: An initialised usbscale object.

usbscale object

usbscaleObject::open( path, callback( usbscaleObject, error ) )

Open an usbscale device, associate it to this object, and fire the provided callback upon completion.

The parameters passed to the provided callback function are usbscaleObject which is a reference to the usbscale object, and error which will be an error string in the case of an error, or undefined on success.

Returns: A reference to itself.

usbscaleObject::data( usbscaleEvent )

A virtual method of the usbscaleObject. Reimplement it to handle usbscaleEvents. It can be ignored, but if you ignore it, you might as well not use this module at all.

Usage no npm install needed!