Can I

that seems a little unclear...

I think you'd need more an integrator than a LPF.

Bye. Jasen

ok. All i want is to interface this pulse generator output into a ADC0809 to get the digital output in order to read from parallel port.

there are many options around but this is the way to be implemented.

h> > > Hi ,

Then it is a very silly and convoluted way to implement it. This method will be very inaccurate, almost certainly not accurate enough to count the actual number of pulses, where I assume you don't want even a +/-1 count error? What frequency are you talking about anyway?

You already have a "digital" output, so you are much better off simply feeding the pulses straight into the parallel port as a digital signal. Should be able to count pulses up to at least a few hundred KHz this way, with zero error.

Forget the ADC, you are barking up the wrong tree.

Dave :)

Alright :-x

Thanks for the ideas. I will search a way to feed the pulse into LPT leaving the ADC aside.

David L. J> > ok. All i want is to interface this pulse generator output into a

Simple, if your signal is already TTL level then connect to the LPT port with a bit of wire ;-) One line of code will read if it's high or low. A few more lines of code will count your pulses. Couldn't possibly be any easier.

Dave :)

could you please explain that a bit. Normally, LPT can read parallel data not serial. Am i right ? so how can i use LPT for reading number pf pulses ?

pls enlighten me .

David L. J> > Alright :-x

could you please explain that a bit. Normally, LPT can read parallel data not serial. Am i right ? so how can i use LPT for reading number of pulses ?

pls enlighten me .

David L. J> > Alright :-x

Think of an 8bit parallel bus as being made up of 8 seperate 1bit serial lines. There is essentially no difference. So your parallel port is capable of reading 8 (more actually, as there are a few other input pins too) serial data inputs.

Just feed your TTL signal into (for example) the D0 pin and tie the rest to ground. Then your code is simply:

Start Loop Read data from port While data=0 Read data from port Repeat While data=1 Read data from port Repeat Count=Count+1 End Loop

Plus you'll need a timer or some other way to break out of the loop of course.

To read the data port in say QuickBASIC you'd use the code (from my rusty memory): data=INP(&H378)

Dave :)