hz reader and switching

prochips

hello
I·trying to·write the code for bs2 oem·,· for reading hz of 5v square wave and later trigger relay if the Freq is > 120hz
but dosent work

·thanks
·wilson

Post Edited (prochips) : 3/21/2007 4:44:12 AM GMT

stamptrol

Wilson,

Everything looks OK.

Are you sure the the square wave is actually swinging the stamp pin 15 from 0 to 5v? Also, is the negative from the square wave source tied to the stamp's negative?

You can reduce the 10K resistor down to 100 ohms or so when inputing a ttl signal.

Cheers,

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Tom Sisk

http://www.siskconsult.com
·

allanlane5

I see no ground input indicated -- have you connected a ground as well as the desired signal?

Phil Pilgrim (PhiPi)

How many pulses per revolution does your motor produce? If it's one — not four — you need to compute RPM as follows:

RPM = Pulses * 120

The same applies to the frequency. Since you're counting for 1/2 second, the frequency you want to check will equal pulses * 2, not pulses.

And finally, in your code, when the value being checked equals 100, the state of the LED doesn't change. Is that what you intended?

-Phil

prochips

ok ,I need conect ground to input signal