Raspberry Pi 4 fan and GPIO breakout board


So up until now Ive been able to get away without using a fan while using my Raspberry Pi’s. Now Ive had time to play around with the raspberry pi 4 I’ve come to the conclusion that you can’t really use it without a fan. I don’t really like the look of the fan options out there so I thought I would have a go at designing my own. Join me below to see how it turned out


  • 40mm fan
  • JST right angle connector
  • ON/OFF switch
  • Long pass though headers
  • Right angle headers
  • 2x M3 bolts
  • 2x M3 nuts

I seen the fan shim from pimoroni but I didn’t like the fact that you needed to run software to use it. I wanted a more straight forward design with just and on/off switch to control it. In another project I wanted away to add a pHAT and still have access to the unused GPIO, I wanted to carry that over to use in this project. All in all I just modified the GPIO splitter design and added the hardware I needed for the fan and called it a day.

All I needed to add was the foot print of the fan and a JST connector and a on/off switch.

Not a fan

I ordered the smallest PC fan I could find, This was a 40mm one. When I got the fan I wasn’t really impressed with how well it cooled the pi down. To do a scientific test I ran a 4k video on Youtube for 1 and a half minutes with the fan in different orientations so see which way worked the best. I think these fans are used to suck the hot air off of CPU/GPU but I wanted to push air onto the pi. This is why I ended up mounting the fan upside down but this means it hasn’t got any cover over it. I also added a heat sink to the CPU to give it that little bit more help


There is one thing I would change about the PCB design, I would have removed more from between the mounting holes of the fan to increase airflow. As it is it does work really well so I’m not too bothered


Board files – https://github.com/facelessloser/rpi_fan_gpio_breakout


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