MQTT Broker - The-Bug-Bashers/iBOARCode GitHub Wiki
Overview
Mosquitto is the central MQTT server that handles all messages between the iBOAR modules (services).
Each service acts as a client that can publish or subscribe to topics.
Basic MQTT Concepts
Clients
- Can publish messages or subscribe to topics.
Topics
- Topics are like communication channels.
- Subscribing to a topic means you receive all messages sent to that channel.
QoS (Quality of Service) Levels
| Level | Description | Example Use |
|---|---|---|
| 0 | Fire and forget (no confirmation). Fast but not guaranteed. | Lidar Controller data updates |
| 1 | Delivered at least once. May duplicate messages. | Remote control commands |
| 2 | Guaranteed exactly once. Slowest but safest. | Critical commands (e.g., startAutonomousMapping) |
Topic Structure
- Format:
topic/subTopic/... - Wildcards:
topic/#: Subscribe to all subtopics.+/subTopic: Subscribe to a specific subtopic under any first-level topic.
🛠️ Commands
| Action | Command |
|---|---|
| Start Broker | sudo systemctl start mosquitto |
| Stop Broker | sudo systemctl stop mosquitto |
| Subscribe to Topic | mosquitto_sub -h localhost -t "example/topic" |
| Publish to Topic | mosquitto_pub -h localhost -t "example/topic" -m "Test message" |