What is it?

• A Clock that gets accurate time from the internet
• T & RH Display
• IoT Sensor sends the T & RH measurement to an MQTT broker
• Displaying outside temperature getting from MQTT

Hardware

• ESP32 or ESP8266 microcontroller development board
• DHT22 Temperature & Relative Humidity Sensor
• 128x64 OLED Display with SH1106 controller and I2C Interface
• A mini breadboard

(Wemos D1 Mini as in the example)

• D1 - SCL of display
• D2 - SDA of display
• D4 - DHT signal
• 5V & GND ... obviously

configuration

Create arduino_secrets.h as below

#define MQTT_BROKER "**.**.**.**"
#define MQTT_USER "..."
#define MQTT_PASS "..."
#define MQTT_TOPIC_PREFIX "dt/..../"
#define MQTT_TOPIC_SUFFIX "/..."

#define THIS_DEVICE_LOC "LivingRoom"

MQTT topic for outside temperature (weather): 'dt/...../outside' i.e., {"temp": 23.0}