MQTT

MQTT is a lightweight, publish-subscribe, machine to machine network protocol for message queue/message queuing service.

I was introduced to this concept when learning about Mission Control at NVIDIA.

Mosquito pub-sub https://chatgpt.com/share/6726b440-b95c-8002-b85a-7a7669edf098

brew services start mosquitto

The configuration file is here on linux:

/usr/local/etc/mosquitto/mosquitto.conf

• In the first terminal, subscribe to a topic:

mosquitto_sub -h localhost -t "test/topic"

• -h localhost: Connects to the broker on your local machine.

• -t "test/topic": Subscribes to the topic “test/topic”.

• In the second terminal, publish a message:

mosquitto_pub -h localhost -t "test/topic" -m "Hello, MQTT"

• -m "Hello, MQTT!": The message to publish.

Mosquito on mac

need to allow anonymous listeners, to make it work not just on mac

• https://www.reddit.com/r/MQTT/comments/lp9j5h/cant_access_mqtt_broker_on_mac_connection_refused/

Find the location of the config file

brew list mosquitto | grep conf

I got it here

/opt/homebrew/Cellar/mosquitto/2.0.20/etc/mosquitto/mosquitto.conf

I add these 2 lines to the config file, which allows incoming connection

listener 1883
allow_anonymous true

I needed to get the ip address of the computer