magnetic stirrer

BOM

4-wire 8mm fan
6Xcylinder magnet(9mm diamater 5mm thickness)
arduino nano
0.96' OLED display module
encoder module
diode
MOS
resistor 1000 100
5VDC-12VDC boost module(if your fan works under 12V)
USB wire

all files are uploaded, feel free to modify any part.