Hi Waqar,

It's kinda scarey to me to think about a "complete" hardware design done after a few hours of reading datasheets, without considerations for software. Any timing analysis/propagation delay calculations done? Signal loading calculations? Power supply loading calculations? Hardware design isn't just a simple matter of connecting DATA01 to DATA01 and calling it good...

But back to pulse dialing. Can you tell me, step by step, how YOU would detect and count pulses coming at you very slowly? Let's get a basic algorithm designed, then we'll discuss how to implement it.

I appreciate your passion for this design work. I think most of us have it, otherwise we'd be in different careers. Your passion will be wasted though if you don't get a good foundation to start on. OK, you now have a few led blink programs, even one that finally uses an interrupt. Remember how long it took us to convince you to use interrupts? Now what you want to do is more complex, and we're trying to get you pointed in the right direction so your efforts won't be fruitless.

Detecting pulses is easy. Determining if a series of pulses is a '5' or a '7' gets a little more involved, and a state machine implementation will be simpler and easier to maintain. So--have you done any research into the matter of state machines (or finite state machines as they are sometimes referred to)?

Come on, work with us. We're trying to help.

Dennis