IO SIGN

[CAROLIVAR]

Hi anyone, today I´ve got two questions I would like to know how read with the instruction (readbit) a bit 0 lever that's to say how to detect that the bit has changed from 1 to 0.
tha second question is reated to software, and C programming, there are many programs that Tom has made as examples, some of them include Loops that are executed for ever. my question how can include two o more than two of these loops in the same program, what's the correct way If so can you post an example.
thanks in advanced
Carlos

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[TomKerekes]

Hi Carlos,

To do something when an input transitions from 1->0 you might write some code to remember the last state and look for the case where the new state is now 0 but the last state was 1. Here is an example:

int NewState,LastState;

LastState=ReadBit(46);

for ( ; ; ) // loop forever
{

NewState=ReadBit(46);
If (NewState==0 && LastState==1)
{

// do something because bit changed from 1 to 0

}
LastState=NewState; // remember the last State

}




For the case where there multiple things that you wish to be continuously monitored you can use a single loop and put all the things you need to do in the same loop. See below:



for ( ; ; ) // loop forever
{

// Do one thing here
// Do something else here

}


HTH

[CAROLIVAR]

Thanks very much, Tom