Purple Air Lambda

Amazon AWS Lambda function for accessing Purple Air API and rendering the result as a web page

Setup Instructions

1. Obtain a Purple Air API key. Email [email protected]; be sure to provide your first and last name.

AWS Deployment Instructions

2. Create an AWS Lambda Node.js function, running on Node.js 18.x
3. Add the environment variable API_KEY to the Lambda configuration; set the value to your Purple Air API read key.
4. Create an AWS API Gateway:

• Select "HTTP API".
• Add an integration to your Lambda function
• Configure the route with the GET HTTP method

5. Configure the AWS API Gateway:

• Select the gateway
• Select Integration
• Create a new Parameter mapping:
  • Response (based on a status code)
  • Response status code of 200
  • Add new mapping for header.Content-Type, Overwrite with value text/html.

Usage Instructions

Access the created Amazon API Gateway, with the specified route, passing in a comma-delimited list of Purple API Sensor IDs for the sensors parameter. You can look up sensor IDs via the Purple Air Map. Click on a particular sensor, and extract the value of the select URL parameter.

e.g. Sample Implementation

Implementation Notes

• Purple Air sensors do not return AQIs. Instead, they return particle counts, which need to be transformed to AQIs.
• The temperature reading is not an environmental value; instead, it is the internal temperature of the sensor itself. Testing has shown this to be 8° above the environmental temperature. Read more here.