RPM counter using 8051

[Sunil Hiremath]

Hi all,

I'm trying to do RPM counter project using 8051. Everything is works fine with 555-Timer output and DAC pulses but when I give the motor rotation pulses from sensor, the RPM count value is oscillating in different values. Details are as below
1. I'm using counter for counting pulses and Timer for one second delay.
2. every one second delay I'm displaying count value and assigning it back to zero.
3. I'm multiplying it by 60 for RPM and displaying the result value in 7-segment display.

Need help Friends...

 

[zeyad.kassaby]

hi sunil what is the variation of readings,what type of sensors you use
I hope i can help you

 

[Sunil Hiremath]

Hi Zeyad,
If the correct RPM is 920, it shows three different values like 900, 960, 1020 repeatedly and I'm using proximity sensor. I'm counting pulses for one second and multiplying it. So the values will be multiples of 60. Is there any method to get more accurate results..