How to skip the first line and output the second?

Question

My question is related to my previous question. These encoder programs outputs two line per pule/tick.

Here is the part of the code I want to use:

void loop()
{
 // Read the status of the inputs
 debouncerA.update();
 debouncerB.update();
 int8_t EncVariation = 0;
 if (debouncerA.rose())
 { // if input A changed from low to high, it was CW if B is high too
 EncVariation = (debouncerB.read()) ? 1 : -1;
 }
 else if (debouncerA.fell())
 { // if input A changed from high to low, it was CW if B is low too
 EncVariation = (debouncerB.read()) ? -1 : 1;
 }
 else if (debouncerB.rose())
 { // if input B changed from low to high, it was CCW if A is high too
 EncVariation = (debouncerA.read()) ? -1 : 1;
 }
 else if (debouncerB.fell())
 { // if input B changed from high to low, it was CCW if B is low too
 EncVariation = (debouncerA.read()) ? 1 : -1;
 }
//
 if (EncVariation != 0) {
 encoder0Pos = encoder0Pos + EncVariation;
 int degs = (encoder0Pos * 6) % 360 ;
 if(degs<0){ degs = 360 + degs; }
 Serial.println (degs);
 }
}

For three inputs/ticks this outputs like:

6

12

18

24

30

36

But I only need the second ones like:

12

24

36

How can I do that? (I need it to send the relevant data do a PC.)

I spend so long time on it couldnt find any solution.

• Code Gorilla: This line looks like its a mistake if(degrees<0){ deg = 360 + degs; } is it correct? You do the calculation of degrees and then start using degs.
• floppy380: was a mistype now i corrected

Answer 1

IF and only IF you want exactly what you have asked for which is alternate lines not to be output then this is a very crude and quick solution.

Outside of loop() add this declaration:

bool skipNextLine = true; // true skips the odd lines, false skips even lines

And change the end of your code like this:

 if (EncVariation != 0) {
 encoder0Pos = encoder0Pos + EncVariation;
 int degrees = (encoder0Pos * 6) % 360 ;
 if(degrees<0){ deg = 360 + degs; }
 if (!skipNextLine)
 { // This will skip alternate lines
 Serial.println (deg);
 skipNextLine = true;
 }
 else
 {
 skipNextLine = false;
 }
 }

• floppy380: Just tried it didnt work. It doesnt output anything
• floppy380: Can it be there maybe another Serial.println (deg); needed before the last if?
• floppy380: should skipNextLine be false at some place?
• Code Gorilla: Blush Whoops. Thanks Mark for editing it.

Answer 2

Use a static variable to count loop execution and only prohibit the very first of every 3 counts.

• floppy380: I tried to use a variable and odd number selection but couldnt achive.