AVR - CPU fan interfacing

[rockstar_212]

cpu fan speed calculation with avr

hello everyone !!
Well what i want to do is, connect a cpu fan to an AVR (Atmega16 or 32) then measure its speed and show on LCD. Then through buttons change the speed. Well what i am looking for is how to measure and change speed ???
any datasheet or doc ??

 

[nandhu015]

interfacing avr to cpu

For this atmega 8 is enough i think.

what type of fan are you using?

Take care while connecting fan to the mc.

Regards
Nandhu

 

[rockstar_212]

cpu fan avr

i think fan with PWM control wire.. Well the question is how to measure speed ?? any tech. documentation ??

 

[laktronics]

avr fan speed control pwm fan

Hi,
May be you can paint the CE sticker in the fan blade assembly black and put uniformly spaced white reflective dots on its periphery, then use a reflective light sensor and count the pulses per second to determine the speed. You can also put these dots on the fan blade itself but the number of dots will be limitted since the fan blades are bent and not plain.
You can also refer the following link for an interesting article on speed mesurement:
http://www.geology.smu.edu/~dpa-www/robo/Encoder/pitt_html/encoders.html

Regards,
Laktronics

 

[rockstar_212]

avr fan

thanks laktronics!!
Well i think the fan itself includes tachometer(as per my knowledge the third wire sends N pulses per round then with timers we have to count these pulses to determine speed.) Now more specific question is where can i get some info about it??


[ 4wire - PWM fan pinouts
1- VCC
2- GND
3- Speed sensor
4- PWM speed control
]

 

[Alan69]

avr cpu fan

Look it up. Search on Panaflo or some other name brand to the manufacturer, and find a datasheet, they're out there, at least from the bigger companies..

 

[rockstar_212]

avr pwm fan

well i searched about 4 days but no luck... some help appreciated!!

 

[Eldhose Chirayil Abraham]

Re: avr pwm fan

well i searched about 4 days but no luck... some help appreciated!!

Try these

**broken link removed**

**broken link removed**