2

I have installed a mini-fan (cooler?) with a heatsink in a Raspberry Pi Model B+ but it is not working. I mean, it is not moving.

The model that I have

Does it only turn on when the processor is hot?

Do I need to install any program or command to make it work?

PS: My overclock is set to medium

This is the kit I have bought

  • 1
    Are you sure it is meant to run continuously and not just when the temp reaches a certain limit. Second the Pi does not need either the heat sink nor the fan at the levels you have it clocked to. Finally you may have better luck resolving this issue with the supplier (though banggood may present a language problem) – Steve Robillard Apr 16 '15 at 19:37
  • pins 2 and 4 are constant +5v, 6 is ground. Try connecting using pin 4 and 6. – wahoozie Apr 16 '15 at 19:46
  • To which pins on the Pi did you connect the fan? – Kolban Apr 16 '15 at 21:14
  • Not sure if it should be running even with cool processator. There was no manuel or documentation with the fan, @SteveRobillard. – dipi evil Apr 17 '15 at 12:12
5

If you plugged it in to pins 4(red) and 6 (black) example and it's not working the fan is likely faulty. Make sure you can spin the fan freely. Use a volt meter to verify. Reverce the plug. If it's faulty don't bother replacing it until the CPU gets over 85 degrees Celsius.

cat /sys/class/thermal/thermal_zone0/temp
  • It´s connected just like this. I´ll try the command to check the temperature. I´m using it only for emulators for now, but I´ll use it for a home cinema and I think 1080p videos will make the things get hot! – dipi evil Apr 17 '15 at 12:08
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    I play1080p60fps 24/7 and it barley gets over 40c. Same deal for when I'm transcoding music for a solid week. The rpi only draws a few watts you need more watts to make more heat, so unless you force turbo and over volt you won't need that fan. If you want to overclock in that way it's better to just go buy something that will play 4k and has USB3 for an extra $50. – user1133275 Apr 17 '15 at 15:23
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That fan has only 2 cables, a black and red, for positive and negative, which means there it is either on or off depending on if it's plugged in or not. There is no thermometer inside measuring how hot the processor is.

Normal computers usually have a fan with 3-4 cables. Two for power, one for controlling the speed, and the last one tells the computer what speed the fan is currently spinning at.

To turn on the fan when the processor gets hot you'd need to write a script that turns on or off a gpio pin depending on the temperature, connect that to the control input of a relay, and connect the fan's negative to the pi's negative, the pi's positive to the input of the relay, and the relay's output to the fan's positive. DO NOT connect the fan directly into the controllable GPIO pins.

Also, it cannot get hot enough to cause damage to itself unless it's somewhere very hot, a lot hotter then room temperature.

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