When The temperature reachs a specific threshold value, the gpio is activated and the transistor lets the fan spin! You can see the current RPi temperature and Fan status using the built-in server functionality or installing the basic RPi-Dashboard: https://github.com/roccomuso/rpi-dashboard
Once the fan starts to spin, there will not be a temperature check for 5 minutes. This behavior avoids too many fan switches in short periods of time.
- Scheme (works on both Raspberry Pi and Raspberry Pi 2 model):
For Raspberry Pi pinout, check out https://www.raspberrypi.org/documentation/usage/gpio-plus-and-raspi2/
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Recommended Transistor: 2N7000
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Recommended Fan: 5V - 0.2A
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You can edit the gpio number, temperature threshold, refresh time etc. directly in the
config.jsonfile:"PIN_NUMBER" : 18, "REFRESH_TIME" : 60, "TEMPERATURE_THRESHOLD" : 45.0 -
Optionally, you can also activate a web server to show the current temperature on
http://ip_address:SERVER_PORT/. Make sure to choose a free port."WEB_SERVER": true, "SERVER_PORT": 4949
Another available option is to pass these parameteres through the CLI:
node index.js -n 18 # 'Choose the GPIO number'
node index.js -p 4949 # 'Start the server on port 4949'
node index.js -t 45 # 'Set a temperature threshold of 45 degrees'
node index.js -r 60 # 'Check the temperature every 60 seconds'
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clone the repo on the
/home/pi/Desktop:git clone https://[email protected]/roccomuso/rpi-fan.git cd rpi-fan && npm install -
add this rule to crontab:
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Launch from CLI
crontab -eand add the following line:@reboot /usr/local/bin/node /home/pi/Desktop/rpi-fan/index.js >/tmp/fan_output 2>/tmp/fan_error
(General console.log and error messages are respectively in /tmp/fan_output and /tmp/fan_error - Update: /tmp/fan_output can now be seen on the web server page.)
You can also better use a process manager (like PM2):
sudo pm2 start index.js --name="rpi-fan"