purple-air

A lambda to monitor a PurpleAir station, and notify on PM2.5 changes. The script monitors a single PurpleAir station, and sends a notification via SNS when the PM2.5 crosses a 'color' threshold.

For myself, I run it on a cron: every 30 minutes during the day.

You can find PurpleAir's API documentation here.

You'll need to set a few environment variables for the script to work:

• bucket_name: the name of an S3 bucket. Used to store the last known state of the sensor being monitored.
• filename: the name of the file in the s3 bucket with the state.
• min_color_notif_threshold: an int, which sets the minimum 'severity' for which to notify. I use 3 (which corresponds to 'orange') for myself.
• sensor_id: the sensor that you want to monitor. You can find the id for every sensor on PurpleAir here.
• topic_arn: the arn for the SNS topic you use.
• counter: which counter you'd like to use readings from. If not set to a or b, the default is to use the average of both. You probably only want to set this to a or b if you know that one of your counters is not working properly for some reason.