react-native-star-micronics-io

React Native Star Micronics IO is a react-native module that will allow you to interact with the Star Micronics scales. This package only currently works with bluetooth connections.

Getting started

$ npm install react-native-star-micronics-io --save

or

$ yarn add react-native-star-micronics-io

Mostly automatic installation

$ cd ios;pod install

or if you are using React Native before version 0.60,

$ react-native link react-native-star-micronics-io

Usage

Setting up the package

You need to setup the package for use by using the setupScales function. You need to wait for the system to be setup before you can discover the scales, you can use onDiscoveryReady to determine this. Use it inside a componentDidMount or before you use discoverScales.

import {setupScales, registerStarListener} from 'react-native-star-micronics-io';

setupScales();

registerStarListener("onDiscoveryReady", (scale) => {
  // we are ready to discover scales 
});

Discover a scale

To start discovering a scale, the first thing you have to do is setup a listener for when a scale is found. Use the registerStarListener function with onDiscoverScale. Then we can call the discoverScales function which will find any scales through bluetooth.

import {registerStarListener, discoverScales} from 'react-native-star-micronics-io';

registerStarListener("onDiscoverScale", (scale) => {
  // do something with the scale we found
});

discoverScales();

Connect to the scale

Once we have found a scale using discoverScales and the onDiscoverScale listener. All we have to do is call connectScale with the payload sent during the onDiscoverScale.

import {registerStarListener, connectScale} from 'react-native-star-micronics-io';

registerStarListener("onDiscoverScale", (scale) => {
  connectScale(scale);
});

Scale state

We can use the listeners onScaleConnect and onScaleDisconnect to check the state of the scales.

import {registerStarListener} from 'react-native-star-micronics-io';

registerStarListener("onScaleConnect", (scale) => {
  // Scale is connected
});

registerStarListener("onScaleDisconnect", (scale) => {
  // Scale lost it's connection
});

Listen to scale data

Once we have connected to the scale and have gotten the onScaleConnect callback, we can start listening to the scale data using onScaleData. It will send an object with weight, type, and unit.

import {registerStarListener} from 'react-native-star-micronics-io';

registerStarListener("onScaleData", (data) => {
  const {weight, type, unit} = data;
  
  console.log("Scale data", weight, type, unit);
});

Stopping a scan

If you want to stop scanning for new scales, use stopDiscoverScales.

import {stopDiscoverScales} from 'react-native-star-micronics-io';

stopDiscoverScales();

Disconnecting a scale

If you want to disconnect the current reader, use the disconnectScale function.

import {disconnectScale} from 'react-native-star-micronics-io';

disconnectScale(scale);