DIY electronic Hydrometer

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Following parts are required:

Plastic cylinder

  • plastic cylinder Petling. These containers are available at eBay as PET-Preforms.



Only needed if you are not using a printed circuit board.

Battery pack

  • 18650 LiIo cell (e.g. Panasonic NCR18650B)


Additional information

Shopping lists:

  • (Note: select the correct battery holder depending on the used board)

GY-521 (Gyro & Acceleration Sensor)

There are several clone sensors available that can be of poor quality. So make sure to buy them from a reliable source, e.g. the one linked in the above liked Wemos documentation.

Other then that, it can be helpful to order not just one sensor and test them before soldering them onto the board.

Here you find 2 options how to proceed with testing gyro sensors: