Rotary Encoder set between two values

Using Arduino Programming Questions
1

Hello Im coding a project and Im having a little issue. Im trying to set my encoder between two values which would be 60-120. I want it to start at 60 and stop at 120 which will cause me to turn the dial in the opposite direction which will result in the numbers dropping back down >=60
Here is my code so far

#include <Encoder.h>
int CLK=39;
int DT=40;
int SW=41;

Encoder myEnc(CLK,DT);


void setup() {
 
  Serial.begin(9600);
  Serial.println("Encoder Position");
}

  long oldPosition = -999;
void loop() {
 

  long newPosition = myEnc.read();
  if(newPosition != oldPosition){
    oldPosition = newPosition;
     if(newPosition >= 121){
    oldPosition=60;
    newPosition=60;
    myEnc.write(60);
  }
      Serial.println(newPosition);
  }
}

As of now it'll start at 1 go to 120 loop back to 60 . It is also displaying negative numbers which is what i don't want. Any help appreciated!

2

Try the constrain() function:
https://www.arduino.cc/reference/en/language/functions/math/constrain/

3 
void loop() {
 int newZ=myEnc.read();
if(newZ<60){myEnc.write(60);}
if(newZ>120){myEnc.write(120);}
newZ = constrain(newZ,60,120);

Serial.println(newZ);
}

Okay so that worked but now it just keeps looping and printing the current value over and over i tried setting a delay but that didn't work

4

Put the Serial.print inside the new/old position compare block.

5

Im not exactly sure what you mean by this?

6

As long as those values are between and including 60 and 120, it is working as expected.

7

What kind Arduino Board? Do you have external interrupt-capable pins available for the encoder? If so, take a look at the "SingleEncoder" example in this library: https://github.com/gfvalvo/NewEncoder

8

it works it just keeps looping so if 60 is displayed on the serial print it keep printing out that number.

9

Mega2560

10

OK, then the library I linked will only work with the encoder connected to these pins: 2, 3, 18, 19, 20, 21.

11

The code works only issue is it keeps looping whatever the current value and i cant figure out why.

12

Is the encoder still working? Try simply:

Serialprintln(myEnc.read());

13

Still loops

14

Screen Shot 2021-12-08 at 7.28.24 PM

15

So, the encoder or wiring is broken? Or did you forget to twist the knob?

Start over with the basic, unmodified example.

16

when i twist the knob it'll change value but just starts looping that current value again

17

That makes sense. You do understand that the loop function loops, don't you?

It is very rapidly and repeatedly called by the hidden function main().

18

so i would have to create its own function? I just figured i can do it inside the loop function cause on the encoder example given in arduino its in the loop function and that works perfectly fine

void loop() {
  long newPosition = myEnc.read();
  if (newPosition != oldPosition) {
    oldPosition = newPosition;
    Serial.println(newPosition);
  }
19

The encoder example above prints only when the encoder value has changed. Your code continuously reads and prints the encoder value.

Both approaches work "fine".

I suggest that you sit down and study the example code until you understand what each line does and why. Only then will you be in a good position to make changes to the code.

20

Hi jdoc,

you seem to not care about a few things that are important when writing code.

indention
your code looks like this

void loop() {
 

  long newPosition = myEnc.read();
  if(newPosition != oldPosition){
    oldPosition = newPosition;
     if(newPosition >= 121){
    oldPosition=60;
    newPosition=60;
    myEnc.write(60);
  }
      Serial.println(newPosition);
  }
}

with comments

void loop() {
 //too 
// many 
//empty lines
  long newPosition = myEnc.read();
  if(newPosition != oldPosition){
    oldPosition = newPosition;
     if(newPosition >= 121){
    oldPosition=60;  // wrong indention
    newPosition=60; // wrong indention
    myEnc.write(60);
  }
      Serial.println(newPosition); // wrong indention and you do not know what te curly bracket is for
  }
}

Your code should look like this

#include <Encoder.h>
int CLK = 39;
int DT = 40;
int SW = 41;

Encoder myEnc(CLK, DT);

void setup() {
  Serial.begin(9600);
  Serial.println("Encoder Position");
}

long oldPosition = -999;

void loop() {
  long newPosition = myEnc.read();
  if (newPosition != oldPosition) 
  { // <<<<<<<=== opening curly bracket
    oldPosition = newPosition;
    if (newPosition >= 121) {
      oldPosition = 60;
      newPosition = 60;
      myEnc.write(60);
    }
    
    Serial.println(newPosition);  //<<<===== printed only if if-condition is true
  }

in your second code

void loop() {
  int newZ = myEnc.read();
  if (newZ < 60) 
  {
    myEnc.write(60); // <<=== executed only when if-condition is true
  }
  
  if (newZ > 120) 
  {
    myEnc.write(120); // <<=== executed only when if-condition is true
  }
  
  newZ = constrain(newZ, 60, 120); // executed EACH time 

  Serial.println(newZ);            // executed EACH time 
}

the curly brackets { } mark start and end of a code-block

Take a look into this tutorial:

Arduino Programming Course

It is easy to understand and has a good mixture between explaining important concepts and example-codes to get you going. So give it a try and report your opinion about this tutorial.

best regards Stefan