Overview

The DragonConnect client is an application written in C that collects and transmits volume up and volume down button presses. The client application will also activate and deactivate an LED. Both functions use the MQTT function of the IoT service.

Configuration

The configuration of the client involves determining the MQTT endpoint, compiling the client application, and copying the certificates of the thing.

Endpoint

The DragonConnect client needs to be configured to use the appropriate MQTT endpoint.

The endpoint can be discovered using the following command

$ aws iot describe-endpoint --query endpointAddress --output text | \
tr :[A-Z] :[a-z]
a1a97y3smarfzt.iot.us-east-1.amazonaws.com

Compiling the Client

Edit the file DragonBoard/src/aws_demo.c and modify the HostAddress appropriately

char HostAddress[255] = "a1a97y3smarfzt.iot.us-east-1.amazonaws.com";

Once the HostAddress has been updated, you will need to compile the application using the included Makefile

$ cd DragonBoard
$ make

Running the Client

The client may now be executed by issuing the following commands

$ cd DragonBoard/bin
$ sudo ./aws_demo

Stopping the Client

The client is stopped using sending a KILL signal to the process which includes typing a Ctrl-C in the terminal running the process.