
The HiLetgo HTU21D temperature and humidity sensor is a great thing. It's very small - runs on 3.3V (don't use 5V) and is very accurate. I've attached an image showing how I connected it to my NodeMCU and output the readings to the serial port. I'm amazed at how small this thing is. Now I can add temperature and humidity readings to all my I2C projects! Two thumbs up!