This project is an extension/modification of JChristensen's original PowerOutageMonitor_HW and PowerOutageMonitor_SW. In addition to recording the start and end times of power outages, this code records the temperature at the end of the outage. This allows the device to be mounted near a fridge to help determing whether food has gone bad during an extended power outage.
The code also enables the arduino-based board to send power outage data via a serial connection to a Raspberry Pi once the power comes back on. Once the Raspberry Pi re-establishes an internet connection after a power outage, it sends the outage data to a REST API in AWS, where it can be stored in DynamoDB and sent to the user in an email message.
The PowerOutageMonitor code works almost entirely the same as the original, except for a few lines of code in the void setup() function which send data of the previous outage to the Raspberry Pi via an FTDI adapter plugged into the board. Once the Raspberry Pi receives the data and has a stable internet connection, it sends the data to a REST API via an HTTP POST request in AWS API Gateway.
An AWS Lambda function can be configured to write the downTime, upTime, and maxTemp to a DynamoDB table that can be viewed in the AWS Console. Lambda can also send the user an email notification via AWS Simple Notification Service.