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PIC based Digital RPM counter

Digital Tachometer or RPM (Revolutions Per Minute) counter is a tool telling the speed of some object rotation. In real world tachometers often can be fount in most cars panels. RPM indicates rotation of engines crankshaft. It usually gives some information to drivers on throttle and gear usage. So PyroElectro have built a digital RPM counter that can be used for most setups like fan motors or other spinning parts. It is based on optical detector where infrared diode is directed to receiver and moving object interrupts signal at some rate. Having this information RPM can be calculated by microcontroller.

Digital RPM Counter

Particularly this project was aimed for measuring RPM of PC fans. So The RPM scale is limited to 1200 – 3200 RPM. Digital RPM value is displayed on standard LCD.

Be sure to check out another great PC fan speed tester.

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  2. Hey!
    This presentation is very helpful for me, but I have so many questions. I am building a similiar rpm counter with Hall sensor, PIC24f08ka101 and Nokia 5110 lcd.
    How did you convert signals into time (rev per minute)? How did you include time? I am not that skilled at pic programming and have some problems understanding you program. I would appreciate your help.

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