node-dymo

node-dymo is a Node.js wrapper that reads from a Dymo brand USB scale. The wrapper provides several events as well as methods to read measurements from the scale.

Dependencies

Libusb is included as a submodule. On Linux, you'll need libudev to build libusb. On Ubuntu/Debian: sudo apt-get install build-essential libudev-dev

Windows

Use Zadig to install the WinUSB driver for your USB device. Otherwise you will get LIBUSB_ERROR_NOT_SUPPORTED when attempting to open devices.

Quick Examples

dymo.on('online', function() {
  console.log('scale was connected/powered on'); // ## ounces(/grams);
});

dymo.on('weight-change', function(obj) {
  console.log(obj.value + ' ' + obj.system); // ## ounces(/grams);
});

console.log(dymo.getWeight()); // { value: 10, system: 'grams' }

Methods

node-dymo provides three methods you can call at any time:

• connect() Connect to the driver, and if a scale isn't immediately online, establish listeners until it becomes online. This method is required in order to gain access to the below methods and listeners
• getWeight() Get the current weight on the scale. Returns an object containing the properties value, and system, with the numerical weight and either ounces or grams respectively
• getOverweightStatus() In the event the scale is overweight, this method will return true, otherwise false
• getStatus() returns either true or false if a scale is available or not.

Events

• online A Dymo scale was connected and powered on
• offline A Dymo scale was powered off/disconnected
• weight-change Fires when the weight on the scale changes. Passes an object to the event listener containing a numerical value property and either ounces or grams for the system property.
• overweight-change Fires when the weight on the scale exceeds it's maximum capacity. Passes a true or false boolean to the event listener depending on whether or not the scale is over or under weight respectively.
• weight Fires when either the weight changes, or when the scale becomes overweight or underweight (combination of both weight-change and overweight-change events)
• end Fires when the scale errors or is powered off