RPI Cooling fan control

[affinite]

Updated flow to incorporate basic PWM fan speed control
Just change values in the "PWM Fan control" function node to configure temperature thresholds

Hi Affinite,
I'm a complete newbie in NodeRed ! Could you help me to implement that function into my configuration, knowing I 'm using a 5 V fan (0.2A) ?
I plan to use your circuit diagram, I would like the fan to start working for T>45°, and full fan speed when T reaches 65° ...

Didier
I dont have access to my RPi at present to remind myself of the specific steps. 
Basically in order to setup the Node Red part you should

copy the code text I provided to the clipboard
Open Node Red and create new node and then paste the code provided into the code box
That code then drives GPIO poin 18 to turn the fan on and off

I dont have my RPi with me so I'll get my spare setup and give some step by step instructions in a day or two.
Regards
Steve