How can I read in sensor data from my ESP32 to DynamoDB?-CodePudding

I'm learning about AWS services and I'm attempting to create a data pipeline from my ESP32 (photoresistor data) to DynamoDB.

I have created a rule that takes incoming MQTT messages from my ESP32 and triggers a lambda function that pushes the data to my DynamoDB.

I have it working for hardcoded values in the lambda function, but how can I modify the following code to read in real-time sensor data from the ESP32?

Here is the lambda code (node.js):

const AWS = require("aws-sdk");
const ddb = new AWS.DynamoDB.DocumentClient({region: 'us-west-2'});

exports.handler = async (event, context, callback) => {
    // Captures the requestId from the context message
    const requestId = context.awsRequestId;

    // Handle promise fulfilled/rejected states
    await createMessage(requestId).then(() => {
        callback(null, {
            statusCode: 201,
            body: '',
            headers: {
                'Access-Control-Allow-Origin' : '*'
            }
        });
    }).catch((err) => {
        console.error(err)
    })
};

// Function createMessage
// Writes message to DynamoDb table Message 
function createMessage(requestId) {
    const params = {
        TableName: 'my-ddd-data',
        Item: {
            'partKey' : requestId,
            'Dropouts': "67476", // this is successfully sent to my database but I'd like real time sensor data
            'Runtime' : "0 mins"
        }
    }
    return ddb.put(params).promise();
}

The json format of the data being fed to this lambda function:

{
  "Dropouts": "1",
  "Runtime": "0 mins"
}

CodePudding user response：

Please, consider logging your event and see how it looks like. Probably it will contain the JSON information from your sensor. I think you could directly pass that information to DynamoDB:

const AWS = require("aws-sdk");
const ddb = new AWS.DynamoDB.DocumentClient({region: 'us-west-2'});

exports.handler = async (event, context, callback) => {
    // Log your event, and see how it looks like
    console.log('Event\n', JSON.stringify(event))

    // Captures the requestId from the context message
    const requestId = context.awsRequestId;

    // Handle promise fulfilled/rejected states
    // Pass the event that is being processed
    await createMessage(requestId, event).then(() => {
        callback(null, {
            statusCode: 201,
            body: '',
            headers: {
                'Access-Control-Allow-Origin' : '*'
            }
        });
    }).catch((err) => {
        console.error(err)
    })
};

// Function createMessage
// Writes message to DynamoDb table Message 
function createMessage(requestId, event) {
    const params = {
        TableName: 'my-ddd-data',
        Item: {
            'partKey' : requestId,
            'Dropouts': event['Dropouts'], // read values from the event
            'Runtime' : event['Runtime']
        }
    }
    return ddb.put(params).promise();
}

Although implemented in Python, I think this tutorial from the Amazon documentation could be of help as well.