Googling around, I discovered that a small fan does indeed knock ~20°C (or even ~30°C ... Of course an ATtiny85 programmed via the Arduino IDE (with a bit of assembler to set the timer to 25kHz) would ...

An Arduino Mini is the brains of the operation, paired with an XY-V17B sound module which plays the required animal wailings. There’s also a 433 MHz radio module that lets the prankster trigger ...

This is an easy tutorial showing how you can control the brightness of an LED or adjust the speed of a DC fan using Arduino Board, a small BC547 transistor and a potentiometer. In my example the whole ...

the controller just needs to keep an eye on the various sensors and provide the fan and heating element with appropriate control signals. An Arduino Pro Mini is more than up to the task ...