timer on 16f877 - Electronic Circuits Projects Diagrams Free

goodpickles · 18th March 2005, 03:32 AM

My 16f877 is running at 4 mhz. I want to use it as a speedometer. I need some way of measuring the elasped time between pulses. I was thinking of useing timer1, but even with the prescaler it will time less than 5 seconds...,or are my calculation incorrect? What is a good way to accomplish this?

**Nigel Goodwin** · 18th March 2005, 08:59 AM

Quote:

Originally Posted by goodpickles

My 16f877 is running at 4 mhz. I want to use it as a speedometer. I need some way of measuring the elasped time between pulses. I was thinking of useing timer1, but even with the prescaler it will time less than 5 seconds...,or are my calculation incorrect? What is a good way to accomplish this?

A speedometer is basically a frequency counter - if you check the MicroChip application notes there's a very old one for a auto-ranging frequency counter.

Or you could check the EPE website, they did a project for a speedometer a number of years ago.

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18th March 2005, 03:32 AM	#1
goodpickles	timer on 16f877 My 16f877 is running at 4 mhz. I want to use it as a speedometer. I need some way of measuring the elasped time between pulses. I was thinking of useing timer1, but even with the prescaler it will time less than 5 seconds...,or are my calculation incorrect? What is a good way to accomplish this?