Laptimer (100th of a second) TMR

Beat Timer

Can anyone design me a circuit that when a button is pressed at intervals the device displays on a LED what the beats per second were? And change as the rate of pressings change. Thus if the button is pressed with 1 second intervals the LED display would show "60". Range up to 60 beats/sec only and small enough to fit inside a hand held stopwatch sized enclosure. Accuracy is not important - within 5%.

I wrote a tutorial on 4 different method to create RTC quality timings from a PIC using interrupts. Here is a tutorial and 4 examples of the approach:

https://www.sfcompiler.co.uk/wiki/pmwiki.php?n=SwordfishUser.SoftRTC

With the correct oscillator you can maintain a 10ms interrupt without a problem. USART is not affected by interrupts (just don't overflow the buffer) and the LCD is synchronous, so it should be fine also.

Beat Timer

I am new on this site so forgive my clumsinesses in replying - I believe this will go to the people who responded. My Beat Timer will be triggered by pressing a button such as on a hand held stop watch. The whole thing must be small enough to fit inside an enclosure the size of a hand held stop watch including battery. It only needs a three figure LED display so up to 99.9 beats per minutes (I might have said "per second" before but it is PER MINUTE) display is fine (actually above 70 beats per minute id redundant). It must switch itself off after a short period. If anyone can do this then would you email me at barrie@look.ca

Did you consider the size of the LED display for a box that size? Kind of reminds me of the old handheld calculators with the magnifier bubbles over the LED digits... maybe they're still around.

Stop brining up old threads! Create your own!