[51] problem with interfacing

[kokanepd]

i am doing the project of frequency measurement.for this ,i used the timer and counter .we know that pulses are required for timer and counter.

for getting the pulse from any wave i used zero crossing detector with the help of lm358.

my project simulation shows correct output if i connect timer pin directly to clock(0-5v),when i connect
timer pin to output of zero crossing detector which is also is 0-5v pulse then simulation is not running i.e not showing the frequency.

guide me about that problem.

 

[zeyad.kassaby]

I hope that you have the data sheet for la358
adjust the ratio between the resistors,at the output yoiu will need for a pull up (4.7k) resistor,then a digital inverter 74ls04 .
have fun

 

[milan.rajik]

Use T0CKI or T1CKI pin if you are using PIC device.