Google IOT MQTT Sample
Overview
This sample application demonstrates a “full stack” application. This currently is able to
- Acquire a DHCPv4 lease. 
- Connect to an SNTP server and acquire current time 
- Establish a TLS connection with the Google IOT Cloud servers 
- Publish data to the Google IOT Cloud 
- Send/Receive keep alive / pings from cloud server 
The source code for this sample application can be found at: samples/net/cloud/google_iot_mqtt.
Requirements
- Entropy source 
- Google IOT Cloud account 
- Google IOT Cloud credentials and required information 
- Network connectivity 
Building and Running
This application has been built and tested on the NXP FRDMK64F. RSA or ECDSA certs/keys are required to authenticate to the Google IOT Cloud. The application includes a key creation script.
Run the create_keys.py script in the
samples/net/cloud/google_iot_mqtt/src/private_info/ directory.
Be sure that they key type generated (RSA or ECDSA) matches your
config of either JWT_SIGN_RSA or JWT_SIGN_ECDSA.
Users will also be required to configure the following Kconfig options based on their Google Cloud IOT project. The following values come from the Google Cloud Platform itself:
- PROJECT_ID: When you select your project at the top of the UI, it should have a “name”, and there should be an ID field as well. This seems to be two words and a number, separated by hyphens. 
- REGION: The Region shows in the list of registries for your registry. And example is “us-central1”. 
- REGISTRY_ID: Each registry has an id. This is a string given when creating the registry. 
- DEVICE_ID: A name given for each device. When viewing the table of devices, this will be shown. 
From these values, the config values can be set using the following template:
CLOUD_CLIENT_ID="projects/PROJECT_ID/locations/REGION/registries/REGISTRY_ID/devices/DEVICE_ID"
CLOUD_AUDIENCE="PROJECT_ID"
CLOUD_SUBSCRIBE_CONFIG="/devices/DEVICE_ID/config"
CLOUD_PUBLISH_TOPIC="/devices/DEVICE_ID/state"