raspberrypi-fan-controller

This program serves to turn your 5v-fan on/off when the pi reaches a certain temperature. This is set to 60°c by default and will turn off when cooled to 45°c, temperature is measured in centigrade. The script utilizes a controlled infinte loop to consisitantly monitor the temperature every 10 seconds. It therefore should be setup so as to run when the pi is first turned on.

The script utilizes < vcgencmd measure_temp > to find the current temperature of the pi.

Setup

Use a S8050 transistor to communicate with the pi & control the fan, you will only need these & wire to connect the circuit making this method quite easy to perform. The below schematic shows the basic layout, the script defines GPIO14 as the default pin to communicate with, it should work with other pins if you wish to change this in your setup. Connections to the GPIO pins & transistor were all performed using dupont connectors.

For software setup follow the below statements

git clone https://github.com/AliCW/raspberrypi-fan-controller.git

Import the following dependencies - you will need to run this in sudo mode for the below rc.local auto-start function to work, otherwise the package will not be available for the root user. But you can always install without the sudo command if not using rc.local for auto-starting the script.

sudo pip3 install schedule

Auto-Start via rc.local

You will probably want to implement some auto-starting features for the fan script so you dont have to run it everytime time you start your pi.

Navigate to the folder the fan-script has been cloned to and type the below

pwd

Copy the path given by the command to the clipboard. Now type the below command to open rc.local in nano editor.

sudo nano /etc/rc.local

Navigate down to the bottom of the file, one line above "exit 0" and type the below

sudo python3 /<paste-path-to-script>/fan_script.py &

Then hold control/command 'X' to exit and 'Y' to save the changes. The '&' is very important as the script uses an infinite loop to detect temperature, if excluded, the pi will not be able to run "exit 0" within rc.local.

Adjusting settings

Alter the GPIO pin if GPIO14 is already in use.

fanPin = 16

You can change the temperature which engages the fan by changing the if statements, the below example changes the script so the fan engages at 70°c.

if temperature >= 70.0: 
    GPIO.output(14,True) #turns the fan on
if temperature < 45.0: 
    GPIO.output(14,False) #turns the fan off