I am using a 12V 4-pin Noctua NF-A8 fan https://noctua.at/en/nf-a8-pwm and want to use the PWM functionality also read the rpm from it. Firstly, I went over dozens of forum discussions on a 5V 4-pin Noctua A4X10 fan which has actually kinda confused me with the fact that do we actually need an NPN transistor circuitry for the PWM pin or not. reading this thread has got a driver circuitry there
The spec pdf says it's not required but they do recommend a CMOS inverter type circuit. regarding the NPN transistor, they printed the same line which idk, of course, a big type error there.
Can anyone first suggest me the wiring schematic to drive a 12V fan where the supply will be given externally since pi has got 5V as max. I am talking about 12V fan variant here. I will be using either GPIO 12 or 13 for PWM pin since it has got hardware PWM and can operate in the frequecny ranges 21K - 28k as recmmonded in the spec sheet by Noctua.Similary for Fan rpm pin , I guess any gpio pin will be fine right?
This guy used no driver circuitry for a 5V fan and has got the results too but again I want to reconfirm this that is it important to have a transistor there for the pwm pin if I am choosing a hardware one (GPIO 12 and 13). I dont want to use and boost converter ciruit at the moment and want to keep design simple as I can so I will power this fan externally.
Moreover my aim is to use a temperature sensor which will measure the ambient temperature and then based on its readings the fan speed will be varied using PWM. Can anyone also recommed me a decent temp sensor to for this application and how to code it using python.Sorry I am beginner level rasberry pi and linux user so need help in this project.