Hello and thanks always
I am building a tachometer based on a series of pulses using a PIC18F2550
I am thinking how to calculate this and so far I have this reasoning.
If the period of a pulse is period and a revolution is completed in say 6 pulses, the period of a revolution is period*6
This period in minutes would be (period*6)/60
Now one the RPM would be RPM=1/((period*6)/60) or 60/(period*6)
Is my calculation correct???
However I found this tutorial
http://www.pyroelectro.com/tutorials/digital_tachometer_rpm/theory.html
and here they calculate the RPM as
RPM=60*(1/Fosc*4)/(Period*6)
(I replaced the 7 for 6 since that is physical)
Now, why would they do this? Does it have to do with the "Period" not being a period in seconds but a value of a Timer register??
Is their reasoning correct? (I suspect their Fosc*4 must be Fosc/4 but I am not sure)
Any help greatly appreciated
I am building a tachometer based on a series of pulses using a PIC18F2550
I am thinking how to calculate this and so far I have this reasoning.
If the period of a pulse is period and a revolution is completed in say 6 pulses, the period of a revolution is period*6
This period in minutes would be (period*6)/60
Now one the RPM would be RPM=1/((period*6)/60) or 60/(period*6)
Is my calculation correct???
However I found this tutorial
http://www.pyroelectro.com/tutorials/digital_tachometer_rpm/theory.html
and here they calculate the RPM as
RPM=60*(1/Fosc*4)/(Period*6)
(I replaced the 7 for 6 since that is physical)
Now, why would they do this? Does it have to do with the "Period" not being a period in seconds but a value of a Timer register??
Is their reasoning correct? (I suspect their Fosc*4 must be Fosc/4 but I am not sure)
Any help greatly appreciated