IoT Devices Blink

IoT Devices

A monorepo for AWS IoT experiments and hardware prototypes built around ESP32 boards, MQTT messaging, custom PCB designs, and a local dashboard for visualizing device events.

This repository contains end-to-end building blocks for connected devices:

• ESP32 firmware publishers/subscribers
• AWS IoT Core infrastructure defined with Terraform
• KiCad PCB projects for multiple device types
• A Blink dashboard (Node.js backend + React frontend)

Table of Contents

• Monorepo Structure
• Getting Started
  • 1. Clone the Repository
  • 2. Provision AWS IoT Infrastructure
  • 3. Configure and Flash Firmware
  • 4. Run the Blink Dashboard
  • 5. Open PCB Projects (Optional)
• Device Topics and Roles
• Hardware Notes
• Contributing
• License
• Support
• Acknowledgments

Monorepo Structure

• Firmware/ - Arduino firmware for Blink, Generic, Door Sensor, GPS, and Temperature device variants.
• Terraform/ - Infrastructure as code for AWS IoT Things, certificates, and policies.
• Dashboard/ - Local dashboards built with node and express.
• PCB/ - KiCad projects for Blink, Door Sensor, GPS, and Temperature hardware.
• Case/ - Mechanical/case assets.

Getting Started

Before starting, install:

1. Clone the Repository

git clone git@github.com:ImSeanConroy/iot-devices.git
cd iot-devices

2. Provision AWS IoT Infrastructure

1. Configure AWS credentials (or run aws configure).

export AWS_ACCESS_KEY_ID=<your-access-key>
export AWS_SECRET_ACCESS_KEY=<your-secret-key>
export AWS_REGION=<your-region>

2. Deploy infrastructure.

cd Terraform
terraform init
terraform apply

3. Retrieve generated values.

terraform output root_ca_url
terraform output device_client_ids
terraform output device_certificates
terraform output device_private_keys

3. Configure and Flash Firmware

1. Choose a firmware target, for example:

   • Firmware/BlinkPublisher/BlinkPublisher.ino
   • Firmware/BlinkSubscriber/BlinkSubscriber.ino
   • Firmware/GenericPublisher/GenericPublisher.ino
   • Firmware/GenericSubscriber/GenericSubscriber.ino

2. In the selected folder, copy secrets.h.template to secrets.h.

3. Update secrets.h with:

   • WIFI_SSID and WIFI_PASSWORD
   • AWS_IOT_ENDPOINT
   • Root CA certificate
   • Device certificate and private key

4. Compile and upload from Arduino IDE.

4. Run the Blink Dashboard

The Blink dashboard lives in Dashboard/blink/.

1. Prepare backend cert files:

cd Dashboard/blink/backend/src/certs
cp cert.pem.example cert.pem
cp key.pem.example key.pem
cp rootCA.pem.example rootCA.pem

2. Start backend (default http://localhost:3000).

cd ../../
npm install
npm run dev

3. Start frontend (Vite, usually http://localhost:5173).

cd ../frontend
npm install
npm run dev

5. Open PCB Projects (Optional)

Open any KiCad project in PCB/, for example:

• PCB/IoT_Devices_Blink/IoT_Devices_Blink.kicad_pro
• PCB/-IoT_Devices_Door_Sensor/
• PCB/-IoT_Devices_GPS/
• PCB/-IoT_Devices_Temperature_Sensor/

Device Topics and Roles

Terraform currently defines devices in Terraform/main.tf.

• Active by default:
  • door_sensor_publisher -> topic iot-devices/door-sensor
• Present but commented out:
  • Blink publisher/subscriber/dashboard
  • Generic publisher/subscriber
  • Temperature publisher
  • GPS publisher

To enable additional roles, uncomment the corresponding entries in local.iot_devices and re-run terraform apply.

Hardware Notes

• Firmware targets Seeed Studio XIAO ESP32C3-class boards.
• Blink subscriber firmware expects a WS2812-compatible LED connected to the configured pin.
• PCB designs are maintained in KiCad and can be exported for fabrication.

Contributing

Contributions are welcome. Please open an issue or fork the repository, create a new branch (feature/your-feature-name) and submit a pull request for any enhancements or bug fixes.

License

This project is licensed under the MIT License - see the LICENSE file for information.

Support

If you are having problems, please let me know by raising a new issue.

Acknowledgments

This project was made possible thanks to the following resources:

• AWS re:Post - Publish a MQTT Message to IOT Core inside a Lambda function with Node and SDK 3
• AWS Samples - Several Arduino examples for AWS IoT projects using ESP32.