MQTT in MATLAB example using JSON messags

jsonMQTTTest.m

function jsonMQTTTest
clc
fprintf("Connecting...\n");
mqttClient = mqtt('tcp://broker.hivemq.com')
subscribe(mqttClient,'fisherds',"Callback",@myCallback);

for k = 60:20:100
    currentMessage = sprintf('{"type": "motor/go", "payload": [%d, %d]}', k, k);
    publish(mqttClient, 'fisherds', currentMessage);
    pause(1);
end

publish(mqttClient, 'fisherds', '{"type": "motor/stop"}');
pause(1);  % Allow the last message to finish before closing
unsubscribeAll(mqttClient)
end

function myCallback(topic, message)
    fprintf("Received message: %s\n", message)    
    messageCell = jsondecode(message)
    messageType = messageCell.type
    payload = messageCell.payload
    leftWheelSpeed = payload(1)
    rightWheelSpeed = payload(2)
end