How to make a tachometer

[timoteo_mendes]

hello,

I am tring to make my on tachometer using a pic 16f628 with internal oscillator and a lcd display.
until now i could put the text for speed in the first line and in the second with rb3 i put a count of the pulses i have...
I know there are lots of way to resolve the same problem, here i would like to know a sugestion how to resolve this.
basicaly what i need is to count the number of pulses in rb3 divide that value by the sample time and multiply by 60 to have it in rpm.
I can use CCP or timers with interrupt is true? the problem is that i don't know how to do it...
any help or sugestion is well came.

Thanks
Tim

 

[3v0]

This question is asked very frequently. Checkout the may examples of tachs on the web. Start breading the circuits and play with the code. Then if you have question come back and ask.

 

[crust]

Also take a look at "frequency counters" as they are pretty much the same except in RPM, they are reading in cycles/second. Multiply by 60 to get cycles/minute.

 

[Sceadwian]

The internal oscillator isn't going to give you very accurate results. Frequency counters should run off a decent voltage regulator and a crystal oscilator.

 

[Gayan Soyza]

http://www.geocities.com/ilufa/DST_E.htm