IoT Traffic Lights

Traffic Lights solution to control traffic lights, setup on the Raspberry Pi GPIO board.

Application Design

Raspberry Pi Breadboard Wiring

Master source for the breadboard wiring can be found in the IoT.TrafficLights.Breadboard.fzz file. The file also allows to simulate the solution in the Fritzing application.

Hardware Specification

Component	Description
Raspberry Pi	Raspberry Pi 4 Model B Rev 1.5, 4GB RAM Linux 6.1.0-rpi4-rpi-v8 Debian GNU/Linux 12 (bookworm) arm64 architecture
Breadboard and wiring	1x 830 hole breadboard and 10x standard wires
LEDs	2x Green LEDs 2x Red LEDs 1x Amber LED
Resistors	5x 330 Ohm
Motion Sensor	1x HC-SR501 type motion sensor

Projects

Name	Description
IoT.TrafficLights.Domain	Domain project containing reusable models, modules and data repositories.
IoT.TrafficLights.Api	Api (REST) project used to control the traffic lights module and access traffic lights execution logs.
IoT.TrafficLights.Web	Web app project used to control the traffic lights module from a Razor UI HTTP web app client.
IoT.TrafficLights.Console	Console app used to run traffic lights module or traffic sensor module.

Deployment

The easiest way to deploy the IoT Traffic Lights application is to run the docker-compose.yaml Docker Compose file with the following command. This will deploy all the containers, volumes and networking on the Docker instance.

docker compose -f docker-compose.yaml --env-file vars.env up -d

To remove the IoT Traffic Lights application from Docker instance, use this command. This will remove all the containers, volumes and networking from Docker instance.

docker compose -f docker-compose.yaml --env-file vars.env down

The vars.env file provides all the environment specific configuration for the application. Use this table below as guide to configure the deployment.

Key	Values	Description
ENVIRONMENT	Development, Test, Production	Defines the release environment.
COMPOSE_PROJECT_NAME	dev-iot-trafficlights, test-iot-trafficlights, prod-iot-trafficlights	This is used to prefix resources and set environmental boundaries for the application components. It allows to run Dev, Test and Prod simultaneously on the same Docker instance at the same time and not clash with each other.
COMPOSE_PROFILES	Mock, SQLite, MySql, MongoDb	Defines which application components are created and used as backend data storage, i.e. SQLite, or MySql or MongoDb database or Mock in-memory only hard-coded data samples.
DB_DIR_SQLITE	C:\Path\SQLite or /home/path/sqlite	SQLite database folder location where the database artifacts are stored.
DB_PORT_SQLITE	30xx, ex. 3017	Port number to access SQLite database.
DB_DIR_MYSQL	C:\Path\MySql or /home/path/mysql	MySql database folder location where the database artifacts are stored.
DB_PORT_MYSQL	33xx, ex. 3317	Port number to access MySql database.
DB_DIR_MONGODB	C:\Path\MongoDb or /home/path/mongodb	MongoDb database folder location where the database artifacts are stored.
DB_PORT_MONGODB	270xx, ex. 27017	Port number to access MongoDb database.
DB_PWD	Password	Password to access the database, only applicable to MySql root user.
API_PORT	80xx, ex. 8011	Port to access the Api.
WEB_PORT	80xx, ex. 8014	Port to access the Web app.
LOGLEVEL_CONSOLE	Verbose, Debug, Information, Warning, Error, Fatal	Log levels for the console output.
LOGLEVEL_DATABASE	Verbose, Debug, Information, Warning, Error, Fatal	Log levels to log in the Database.
GPIO	Mock, Pi	Define if the application is wired to Raspberry Pi or just in a Mock mode.
RUN	RunMock, RunTrafficSensor, RunTrafficTimer	Program to run in the Console app.

Modules

TrafficControl

Use to control the traffic and pedestrian lights pattern, turning different light modes through GPIO pins.

LED Light	GPIO Pin
Traffic Red	26
Traffic Amber	19
Traffic Green	13
Pedestrian Red	27
Pedestrian Green	17

Type	Description
Mock	Module is controlled through mock calls, no Pi required.
Pi	Module is executing GPIO commands on the Pi. Raspberry Pi is required for this.
Api	Module calls through HTTP layer to the IoT.TrafficLights.Api. Refer to IoT.TrafficLights.Api configuration and ports below. Sample URL: http://localhost:8011

TrafficSensor

Use to control the motion detection sensor, turning on or off sensor mode through GPIO pins.

Sensor	GPIO Pin
Sensor On	21

Type	Description
Mock	Module is controlled through mock calls, no Pi required.
Pi	Module is executing GPIO commands on the Pi. Raspberry Pi is required for this.

Repository

Backend database details, used across all projects in the IoT TrafficLights solution.

Object	Name	Description
Database	IotTrafficLights	Main database name for the IoT TrafficLights solution.
Tables	ApiLogs	Store the API execution logs.
	WebLogs	Store the Web App execution logs.
	ConsoleLogs	Store the Console execution logs.
	TrafficLogs	Store Traffic Lights execution logs.

Configuration

Name	Description
Mock	Defaults to empty string (""). Hard coded in-memory, stateless, mock calls to sample data set, no data persistance. Connection string is not required.
SQLite	SQLite backed database that is stored on a host machine file system as .db file. Communication with the database through a file system. Default SQLite deployment doesn't configure any user credentials and can be accessed without such permissions. NOTE: Works on AMD and ARM architectures.
SQLite.Url	PATH_TO_DATABASE\DATABASE_NAME.db
MySql	MySql backed database that can run either in Docker container or as standalone installation on the machine. Communication with the database is on port 33xx over the network (IP Address) or localhost (127.0.0.1). Use the default root account and password of your choice that is configured during MySql database deployment. NOTE: Works on AMD and ARM architectures.
MySql.Url	Server=127.0.0.1;Port=33xx;User ID=root;Password=YOUR_PASSWORD;Database=DATABASE_NAME
MongoDb	MongoDb backed database that can run either in Docker container or as standalone installation on the machine. Communication with the database is on port 270xx over the network (IP Address) or localhost (127.0.0.1). Default MongoDb deployment doesn't configure any user credentials and can be accessed without such permissions. NOTE: Works on AMD and ARM architectures (Pi 5 or higher).
MongoDb.Url	mongodb://localhost:270xx