We go to use pin D1 (SCL) and D2 (SDA) Now connect power supply to sensor (3V3 to VIN and GND to GND) Register to ThingSpeak.com and create a new channel We need field for temperature, humidity and air pressure. This is main dashboard with charts builds on captured data. Copy the Write API Key Insert your wifi name (SSID), password and paste your Write API Key to const api_key You can also change the delay between masurements. Compile and upload your sketch into the board. Blinking LED indicates Wemos tries to connect to wifi. Connection is ready and data are uploaded via ThinkSpeak API to server. Here we can check transfered data.