A Hall-effect sensor-based magnetic pole indicator for Arduino. Allows you to quickly and easily determine the poles of permanent magnets.
To build it yourself, you'll need:
Printed parts
Li-ion charging module with protection https://aliexpress.ru/item/4001196670805.html
Hall sensor module https://aliexpress.ru/item/32900981503.html
Latching microswitch https://aliexpress.ru/item/32872196282.html
3.7V Li-ion battery up to 50 x 16 x 5 mm in size