ng-scales

Angular library for connecting to USB scales

Demo

Check out the live demo

Get started

Installing

Add the npm package to your app

npm i ng-scales

Using in angular application

Add the providers in the app.config.ts

providers: [
  ...
  provideNgScales()
  ...
]

The easiest way to integrate is the provided button directive which handles connecting and disconnecting from the scale. Add this into your template

<button libNgScalesConnectionButton></button>

Import the component

@Component({
  ...
  imports: [NgScalesConnectionButtonDirective]
  ...
})

Hardware Support

Built in support

Vendor	Vendor ID	Product	Product Id	Name	Verified
DYMO	2338	M25	32771	DYMO M25 25 Lb Digital Postal Scale	✅

Adding support for additional scales

You can add a new scale by providing additional mappers. The mapper function coverts the array buffer into a usable data object

  provideNgScales({mappers: [
    {
      vendorId: 2338,
      productId: 32771,
      mapper: (arrayBuffer: ArrayBuffer): HardwareScaleReportEvent => {
        const d = new Uint8Array(arrayBuffer);
        let weight = (d[3] + 256 * d[4])/10;
        if (d[0] === 5) {
          weight *= -1;
        }
        return {
          units: d[1] === 2 ? 'grams' : 'ounces',
          weight
        };
      }
    }
  ]})