I want to detect positive and negative edges that are generated by a limit switch.
1. I am using P89V51RD2 . 2. I want to do two different tasks upon these edges. 3. I am making use of capture module of p89v51rd2(for rising edge) and INT0 (for falling edge). since it will give rise to two different ISRs.
4. that's why I have shorted the two pins viz. INT0 & CEX0 (p1.3), and given to the switch.
but I am not getting the correct results.??
Is there any wrong in combining these two inputs(interrupts) ??
if both pins are configured quasi, there is no risk tying them together
Erik
Thanks for the reply Erik.
can you tell me the technical meaning of Quasi?
it means simillar...but in what sense??
are they must be configured as input ??
waiting for the reply..
Why are you waiting for an answer?
I did something daring - I visited Google and tried "8051 quasi" as search term.
Second hit I saw contained the term "Quasi-bidirectional IO", which sounded quite interesting. Within just a couple of seconds I could find lots of information answering what the technical meaning is.
Maybe you should try Google some time. Other people have actually managed quite well, relying on Google for quick answer to questions.
yeah. cmon man. dont waste there time with trivial questions. they are on a highest level and they were never noobs. they must not get disturbed with us stupid nooby stuff!
We were noobs too. But we didn't have access to any web forums to jump to whenever we wanted to know something. So we did instead read the datasheets. Or checked what books the local library had. Or what books we could buy.
And what we learned from that, is that my looking for information you can get progression without having to sit and wait for someone else to step in and hand over the answers. Not only that, but actively searching for information has a nice side effect - you tend to find other interesting information at the same time. So you learn the answers to questions you didn't knew to ask yet.
Today, we have an internet generation, where step 1 is to ask on the net. That basically short-circuits the logic thinking skills, making sure the brain never get the exercises it needs.
R&D is very much problem solving. So being able to analyze problems and try to see them from multiple directions is vital.
but I am not getting the correct results.?? what results were you expecting and what are you getting?