PART 2: displaying temperature data as a graph on your phone for free

PART 2: covers publishing this data to a free, public MQTT broker and displaying it as a graph using the free "IoT MQTT Panel" Android app
NodeMCU lots available cheaply for example:
www.aliexpress...
DHT11 sensor with wire also readily and cheaply available:
www.aliexpress...
Free MQTT brokers (no username or password needed - but your data is public!):
mqtt://test.mosquitto.org:1883 (see test.mosquitto.org)
mqtt://broker.emqx.io:1883 (see www.emqx.com)
(NOTE: I used Linux laptop and chromium to access the Tasmota website: tasmota.github... to flash the firmware to the NodeMCU over the USB cable as I have problems with Windows 11 USB drivers)
(PART 1: Use a NodeMCU (5 euros) to collect data from a DHT11 temperature / humidity sensor (3 euros with connection wires) and display this data in a browser on your phone.)