Update!!! this project has been updated to use Amplify Gen2 to deploy the backend services in AWS.

This application demonstrates a web application dashboard receiving real-time updates from a series of IoT sensors. It depicts a fictitious set of pH sensors deployed around the San Francisco Bay. The solution is built with React, AWS AppSync, Amazon Location Service, AWS Amplify, and AWS IoT technologies.

The sensors are represented as the colored dots. Their color will fluxuate between red, green, and yellow based on the messages received from the sensors.

1. The sensor component is developed with the AWS IoT Device SDK for JavaScript. The sensors are registered as Things in IoT Core and publish random values to the Cloud on a configurable frequency. Metadata about each sensor, such as its geolocation, is stored in a Thing Shadow.

2. Rules in IoT Core subscribe to the message topic and forward the JSON payload to a Lambda function and the IoT Analytics pipeline.

3. The Node.js Lambda function executes a GraphQL mutation in AppSync. The mutation saves the sensor's value in DynamoDB and broadcasts the value in real-time to the web dashboard. The Lambda function uses an IAM role and policy to obtain permissions to interact with AppSync.

4. The React web dashboard application is written in JavaScript and subscribes to the AppSync sensor subscriptions. When new values are received, an Amazon Location Service map is updated in real-time to reflect the new sensor values. The application uses Cognito to authenticate users and allow them to perform the AppSync subscription.

The following software was used in the development of this application. While it may work with alternative versions, we recommend you deploy the specified minimum version.

1. An AWS account in which you have Administrator access.

2. AWS CLI (v2.15.3) the AWS Command Line Interface (CLI) is used to configure your connection credentials to AWS. These credentials are used by the CDK, Amplify, and the CLI.

3. Node.js (v18.19.0) with NPM (v10.1.0)

Clone this code repository

git clone https://github.com/aws-samples/aws-appsync-iot-core-realtime-dashboard.git

Switch to the project's web folder

cd aws-appsync-iot-core-realtime-dashboard/web

Install the web app's Node.js packages

npm install

Deploy the Infrastructure with Amplify Gen2

npx ampx sandbox

The deployment is complete when you see the following output:

File written: amplify_outputs.json

Press CTRL-C to exit the deployment.

Resources created in your account include:

• AppSync GraphQL API
• DynamoDB Table
• Cognito User Pool
• Lambda Functions (2)
• IoT Rule
• Amazon Location Service Map

Install the IoT sensor simulator

Open a new terminal window then switch to the app's sensor folder (aws-appsync-iot-core-realtime-dashboard/sensor).

Install the Node js packages, and run the Node js app to create your sensor as a Thing in AWS IoT Core. It will also create and install the certificates your sensor needs to authenticate to IoT Core.

From the app's sensor folder:

npm install
node create-sensors.js

Note - the profile and region arguments are optional. If not specified the app will create the sensors using your default AWS Profile in us-east-1

Start the IoT sensor

From the sensor terminal window:

node index.js

You will see output from the app as it connects to IoT Core and publishes new messages for six sensors every few seconds.

published to shadow topic $aws/things/sensor-sf-north/shadow/update {"state":{"reported":{"name":"SF Bay - North","enabled":true,"geo":{"latitude":37.800307,"longitude":-122.354788}}}}

published to telemetry topic dt/bay-health/SF/sensor-sf-north/sensor-value {"pH":5,"temperature":54.7,"salinity":25,"disolvedO2":6.1,"timestamp":1591831843844}

Start the web app

Switch back to the terminal window pointing to the web folder and run:

npm run dev

This will launch the application in your machine's default web browser.

Sign-up and Sign-in

The web app requires users to authenticate via Cognito. The first screen you will see is a logon screen. Click the Create account link and create a new account using your email address.

Cognito will then email you a confirmation code. Enter this code into the subsequent confirmation screen and logon to the app with your credentials.

Use the web app

You should now see a screen similar to the one at the top of this guide. If you look at the terminal window running the sensor app, you shoud see the values being published to the Cloud reflected in the web app's sensor icon in real-time.

Once you are finished working with this project, you may want to delete the resources it created in your AWS account.

From the web folder:

npx ampx sandbox delete

From the sensor folder:

node delete-sensors.js

Note - the profile and region arguments are optional. If not specified the app will delete the sensors using your default AWS Profile in us-east-1

This sample code is made available under a modified MIT-0 license. See the LICENSE file.