Raspberry-pi-automatic-active-cooling

An automatic fan speed control for RPI4 depending upon the temprature using python script.

Hardware

Simple hardware using FET to control fan switching.

R1 to discharge the gate capacitance of the MOSFET, and R2 to limit the current which is created if you change the signal at the gate. R1 is usually a few k Ohms, and R2 a few 100 ohms.

Software setup

• Power up the RPI and open terminal and create a new directory named scripts

cd
mkdir Scripts

• Change directory to Scripts

cd Scripts

• Now copy fancontroll.py & launcher.sh from PC to RPI Scripts folder, this can be done using many methods here I will use SCP command for sending files over SSH

scp fancontroll.py root@192.168.43.112:Scripts/

scp launcher.sh root@192.168.43.112:Scripts/

note that ssh client should be installed on both sides (PC & RPI) use the below code to install. apt-get install openssh-client

• Now run the python code using the command python fancontroll.py

• Now we add a directory to store the error log files

cd 
mkdir logs

• Now to automatically start the python script on rpi reboot use the following commands The below code makes launcher.sh files executable

cd
cd Scripts/
bash launcher.sh
sh ./launcher.sh

chmod 755 launcher.sh

Now open crontab to add launcher.sh path to automaticaly start after reboot

sudo crontab -e 

At the end of the file add the following line and save the file

@reboot sh /root/Scripts/launcher.sh >/root/logs/cronlog 2>&1

Note to add the directory loaction according to your RPI, to get the path of directory use the command pwd

• Now reboot the RPI to get the changes saved

References :

• Andreas Spiess 1
• Andreas Spiess 2
• SCP File Transfer RPI Documentation