Power Supply (x1): 5V–12V DC adapter for powering the Arduino, or in my case, we use 2S Lithium-ion battery connecting to Vin pin. Below you can see the circuit diagram used in the ... starting from ...

Temperature-based cooling fan using Arduino, a DC motor, and RGB LED. Fan speed and LED color adjust dynamically at 85°F and 88°F to indicate cooling states and regulate heat buildup in nearby objects ...