I built this board so I can assemble various ESP8266 based sensors using easily available breakout boards.

I designed this board to support the following sensors. Check the schematics for the pinout.

I2C:

• BME680: temperature, humidity, pressure, VOC
• BH1750: ambient light
• SH21: temperature, humidity
• and of course any other I2C sensor that have the same pinout as one of the 3 above

1-wire:

• DHT11/DHT22: temperature and humidity with the 4.7k resistor
• DS18B20 temperature probes with the 4.7k resistor

Others:

• Current clamp for power consumption measurement, also the requited 2 x 10k resistor and 10uF capacitor
• RCWL-0516: radar motion sensor
• 4 Relay relay board
• Header to access all ESP GPIO pins

You need a Wemos D1 mini as the ESP microcontroller board, and the sensors mentioned above that is available in many different places. Some of the more exotic parts:

RCWL-0516 microwave motion sensor: https://www.aliexpress.com/item/32948027705.html

SCT-013-000 YHDC 30A current clamp: https://www.aliexpress.com/item/32708887594.html

Powering this board

There are 3 different ways this board can be powered:

1) Mains power

Use a screw terminal on the top and a Hi-Link HLK PM01 (https://www.aliexpress.com/item/32408565688.html) 5V power supply. There is also a footprint for a varistor to clamp high voltage transients (pick a part suitable for your mains power), and also a regular fuse holder. I am using 100mA slow blow fuse there. If you don't want to use a fuse, bridge the terminals with a wire.

2) 5V

Use the H3 terminal to supply the board with 5V. Note the correct polarity, there is no polarity protection in the board.

3) DC power

Use the H4 terminals to supply 6-24V DC. Note the correct polarity, there is no polarity protection in the board. Also populate the footprint for the small buck converter (https://www.aliexpress.com/item/4000076471931.html) to transform the 6-24V to 5V.

Firmware and Tutorials

My intro to this board can be seen in this video: https://youtu.be/WzjfJQtedCA

I am planning to release more videos on how to build sensors and build a firmware using ESPHome.