AWS Greengrass
Developer Guide

Module 5: Interacting with Device Shadows

This advanced module shows you how AWS Greengrass devices can interact with AWS IoT device shadows in an AWS Greengrass group. A shadow is a JSON document that is used to store current or desired state information for a thing. In this module, you discover how one AWS Greengrass device (GG_Switch) can modify the state of another AWS Greengrass device (GG_TrafficLight) and how these states can be synced to the AWS Greengrass cloud:

                AWS Greengrass core is connected to a traffic light device shadow and a light switch

Before you begin, make sure that you have completed Module 1, Module 2, Module 3 (Part 1), and Module 3 (Part 2). You should also understand how to connect devices to an AWS Greengrass core (Module 4). You do not need other components or devices. This module should take about 30 minutes to complete.