Creating a Lambda Rule

In the AWS Lambda console, choose Create a Lambda function.

For the filter, type hello-world, and then choose the hello-world blueprint.

On the Configure triggers page, select the box to the left of the Lambda icon, and select AWS IoT from the drop down menu.

On the Configure triggers page enter your button's device serial number (DSN). Your DSN is printed on the back of your AWS IoT button. If you have not already generated a certificate and private key for your AWS IoT button, select Generate certificate and keys. Otherwise, skip to step 6.

Select the links to download your certificate PEM and private key. Save these files in a secure location on your computer.

Follow the instructions on the screen to configure your AWS IoT button.

Ensure that the Enable trigger checkbox is selected and select Next.

On the Configure function page, type a name and description for the Lambda function. In Runtime, choose Node.js 4.3.

Scroll down to the Lambda function code section of the page. Replace the existing code with the following:

console.log('Loading function');
    // Load the AWS SDK
    var AWS = require("aws-sdk");
    
    // Set up the code to call when the Lambda function is invoked
    exports.handler = (event, context, callback) => {
        // Load the message passed into the Lambda function into a JSON object 
        var eventText = JSON.stringify(event, null, 2);
        
        // Log a message to the console, you can view this text in the Monitoring tab in the Lambda console or in the CloudWatch Logs console
        console.log("Received event:", eventText);
        
        // Create a string extracting the click type and serial number from the message sent by the AWS IoT button
        var messageText = "Received  " + event.clickType + " message from button ID: " + event.serialNumber;
        
        // Write the string to the console
        console.log("Message to send: " + messageText);
        
        // Crewate an SNS object
        var sns = new AWS.SNS();
        
        // Populate the parameters for the publish operation
        // - Message : the text of the message to send
        // - TopicArn : the ARN of the Amazon SNS topic to which you want to publish 
        var params = {
            Message: messageText,
            TopicArn: "arn:aws:sns:us-east-1:123456789012:MyIoTButtonSNSTopic"
         };
         sns.publish(params, context.done);
    };

Scroll down to the Lambda function handler and role section of the page. For Role, choose Create a custom role. The IAM console will open, allowing you to create an IAM role that Lambda can assume when executing the Lambda function.

To edit the role's policy to give it permission to publish to your Amazon SNS topic:

Choose Allow.

Leave the settings on the Advanced settings page at their defaults, and choose Next

On the Review page, choose Create function.

From the Actions menu, choose Configure test event.

Copy and paste the following JSON into the Input test event page, and then choose Save and test.

In the AWS Lambda console and scroll to the bottom of the screen. The Log output section displays the output the Lambda function has written to the console.

In the AWS IoT console, choose Create a resource.

Choose Create a rule.

Type a name and description for the rule.

Enter the following settings for the rule:

For Choose an action, choose Insert this message into a code function and execute it (Lambda).

From Function name, choose your Lambda function name, and then choose Add action.

Choose Create to create your Lambda function.

In the AWS IoT console, choose MQTT Client.

Type a client ID or choose Generate client ID, and then choose Connect.

Choose Publish to topic.

In Publish topic, type iotbutton/ABCDEFG12345.

In Payload, type the following JSON, and then choose Publish.

{
    "serialNumber" : "ABCDEFG12345",
    "clickType" : "SINGLE",
    "batteryVoltage" : "2000 mV"
}

You should receive a message on your cell phone.