@eisberg-labs/ngx-barcode-scanner

 @NgModule({
   declarations: [
     AppComponent
   ],
   imports: [
     NgxBarcodeScannerModule
   ],
   providers: [],
   bootstrap: [AppComponent]
 })
 export class AppModule { }

import {NgxBarcodeScannerService} from "@eisberg-labs/ngx-barcode-scanner";

@Component({
  selector: 'app-root',
  template: `<ngx-barcode-scanner [(value)]="value"
                     [codes]="['code_128', 'ean', 'upc', 'upc_e', 'ean_8']" [errorThreshold]="0.1" (exception)="onError($event)"></ngx-barcode-scanner>`
    <div style="display: flex; justify-content: space-between; margin: 5% auto">
        <button (click)="onStartButtonPress()">Start</button>
        <button (click)="onStopButtonPress()">Stop</button>
    </div>
})

constructor(
   service: NgxBarcodeScannerService
) {
  //Do constructor things...
}

onStartButtonPress() {
  this.service.start(this.quaggaConfig, 0.1)
}

onValueChanges(detectedValue: string) {
  console.log("Found this: " + detectedValue)
}

onStopButtonPress() {
  this.service.stop()
}