Hi Waqar,

Terry wasn't trying to discourage you, he was merely to get you thinking on the right track, as have any number of others answering your questions.

To successfully do what you are trying to do requires a basic understanding of electronics, the microcontroller you are planning on using, the language you will be programming it with, and engineering. You have been given many suggestions in these areas, but don't seem to appreciate them. They are not meant to discourage, but to educate.

If you really want to learn, hit the books and go through the tutorials here. Get over your phobia of interrupts--I can't imagine any significant piece of code without them. Your pulse dialing decoding will require them, if you want to be able to do anything else.

After you have read the 8051 bible a few times, get the datasheet for the 8051 variant you plan to work with, and read it over and over to find out what's different about it. Those subtle little differences can cause big problems. For example, on the 89C2051, there is a sentence in the datasheet about two port pins that need external pullups...

Once you have decided what I/O your project needs, design the interface circuitry and breadboard it, test it to make sure it works. It turns out in the embedded world a lot of analog design is required.

And of course before you can start writing the code for this new I/O circuitry, you will need to get that LED to blink from a timer interrupt. There is a lot of example code available for you to use, but until you get some basics down you won't know enough to be able to.

Saying you want to build something using your stated bits and pieces, when you don't want to do the basics, comes across as begging for help on a reverse-engineering project that's way over your head.

Dennis