diff --git a/_src/_guides/tutorial-car-telemetry-app.md b/_src/_guides/tutorial-car-telemetry-app.md index 43dce42..2ff5abb 100644 --- a/_src/_guides/tutorial-car-telemetry-app.md +++ b/_src/_guides/tutorial-car-telemetry-app.md @@ -2,12 +2,12 @@ layout: guide title: "Tutorial: How to create a digital twin of your car" -tagline: Learn how to build a telemetry app to track specific dynamic parameters of an asset, such as the mileage of a car. +tagline: Build a telemetry app to track specific dynamic parameters of an asset, such as the mileage of a car. header: header-car.jpg learn: > - How BigchainDB can be used to build telemetry apps to track specific dynamic parameters of an asset - - How assets can be used to represent real objects on BigchainDB + - How assets can be used on BigchainDB to represent real objects - How to make a `CREATE` transaction to digitally register an object on BigchainDB @@ -18,7 +18,7 @@ Hi there! Welcome to our first tutorial! For this tutorial, we assume that you a # About digital twins -We are moving towards an era, where the internet of things is becoming real. Cars become more connected, devices equipped with sensors can communicate their data and objects become smarter and smarter. This triggers the need for a digital representation of these devices to store their data in a safe location and to have a complete audit trail of their activity. This is the core idea of the digital twin of an object. +We are moving towards an era, where the Internet of Things is becoming real. Cars become more connected, devices equipped with sensors can communicate their data and objects become smarter and smarter. This triggers the need for a digital representation of these devices to store their data in a safe location and to have a complete audit trail of their activity. This is the core idea of the digital twin of an object. BigchainDB is an ideal solution to create digital twins of smart devices. In this tutorial, you will learn how to build a simple and basic version of a digital twin of your car, which allows its owner to store and update the mileage of the car. @@ -39,16 +39,16 @@ const BigchainDB = require('bigchaindb-driver') const API_PATH = 'https://test.ipdb.io/api/v1/' const conn = new BigchainDB.Connection(API_PATH, { - app_id: '2db4355b', - app_key: 'b106b7e24cc2306a00906da90de4a960' + app_id: 'Get one from developers.ipdb.io', + app_key: 'Same as app_id' }) ``` # Create a key pair -In BigchainDB, users are represented as a private and public key pair. In our case, a key pair for Alice will be created. Alice will be the owner of the car, and she will be the only one able to create this specific asset and update the mileage of the car. +In BigchainDB, users are represented as a private and public key pair. In our case, a key pair for Alice will be created. Alice will be the owner of the car, and she will be the only one able to update the mileage of the car. Anyone can also verify that Alice is the creator of the car, using her public key. -You can generate a key pair from a seed phrase, so you will just need to remember this particular seed phrase. The code below illustrates that. +You can generate a key pair from a seed phrase using the BIP39 library, so you will just need to remember this particular seed phrase. The code below illustrates that. ```js const alice = new BigchainDB.Ed25519Keypair(bip39.mnemonicToSeed('seedPhrase').slice(0,32)) @@ -56,9 +56,9 @@ const alice = new BigchainDB.Ed25519Keypair(bip39.mnemonicToSeed('seedPhrase').s # Digital registration of an asset on BigchainDB -After having generated a key pair, you now need to register your car in BigchainDB. This corresponds to an asset registration. In our case, an asset will represent an object in real life, namely a car. This asset will live inside BigchainDB forever and there is no possibility to delete it. +After having generated a key pair, you can create transactions in BigchainDB, so you can start registering your car in BigchainDB. This corresponds to an asset creation. In our case, an asset will represent an object in real life, namely a car. This asset will live in BigchainDB forever and there is no possibility to delete it. This is the immutability property of blockchain technology. -First, you need to define the asset field that represents the car. It has a JSON format: +The first thing needed is the definition of the asset field that represents the car. It has a JSON format: ```js const vehicle = { @@ -71,57 +71,60 @@ const vehicle = { } ``` -As a next step, you need to generate a `CREATE` transaction to link the defined asset to the user Alice. To post this transaction in BigchainDB, first you need to create it, then sign it and then send it. There are different methods for each step: +As a next step, you need to generate a `CREATE` transaction to link the defined asset to the user Alice. There are three stepts to post this transaction in BigchainDB, first you create it, then sign it and then send it. There are different methods for each step: ```js function createCar() { // Construct a transaction payload const txCreate = BigchainDB.Transaction.makeCreateTransaction( + // Asset field { - vehicle_number: vehicle.value, - power: vehicle.power, - consumption: vehicle.consumption, + ...vehicle, datetime: new Date().toString() }, - // Metadata contains information about the transaction itself + // Metadata field, contains information about the transaction itself // (can be `null` if not needed) + // Initialize the mileage with 0 km { - mileage: 0 + mileage: 0, + units: 'km' }, - // Output + // Output. For this case we create a simple Ed25519 condition [BigchainDB.Transaction.makeOutput( BigchainDB.Transaction.makeEd25519Condition(carOwner.publicKey))], + // Issuers carOwner.publicKey ) - // Sign the transaction with private keys of the owner of the car + // The owner of the car signs the transaction const txSigned = BigchainDB.Transaction.signTransaction(txCreate, carOwner.privateKey) // Send the transaction off to BigchainDB conn.postTransaction(txSigned) + // Check the status of the transaction every 0.5 seconds. .then(() => conn.pollStatusAndFetchTransaction(txSigned.id)) .then(res => { - console.log('Created Transaction', txSigned) + document.body.innerHTML +='