Turn on LED with one button

[shramik_salgaonkar]

@dpozzi

The issue that if I connect the system, is Off Line. If I disconnect the LEDs before connecting the system and then connect them, everything works normally. That is, I have to start the system with the LEDs disconnected.

how much wattage is your led? The maximum source current of GPIO is about 12mA.
You may check the serial monitor to see if there is any issue by adding #define CAYENNE_DEBUG

Also change if (millis() - lastMillis > 1000) { to if (millis() - lastMillis > 15000) {. You are publishing data at very rapid rate and will hit rate limit. Sending MQTT messages within rate limits