Switch case "stepping through" when i think it shouldnt

Projects Programming
1

So the sketch is to run a home brew kit to make beer, using a "full volume mash" method, once all the mash is complete controlled by a BSC 460, I want a "mashComplete" signal from the BSC460 so open an auto valve to run the mash liquor in to a boil kettle at a controlled rate over a 1 hour period then stop all functions.

Ive attached the Sketch I have so far there is changes to make but I want to understand why its stepping through the switch cases.

Im watching this run via the serial port so I can see it step through straight away.

Any help would be much appreciated

Pesh

sketch_FullVolume_Mash.ino (20.4 KB)

2

which case is it stepping thru unexpectedly?

looks like it conditionally steps from case 0 to 1, and from case 2, meaning it dwells in cases 1 & 2, but advances to case 2 immediately from case 1.

also, since there not case 3, 4, ..., what do you expect to happen when section is incremented in case 2.

i've never seen a switch statement without a default case; not sure what happens

3 
  if    (MashComplete == HIGH);

If MashComplete is HIGH, do nothing. Otherwise, do nothing. Seems pointless.

     {section = section +1;}

{What's} {with} {the} {useless} {braces} {?}

Your case 0 statement does not have an unconditional break statement. It MUST.

4

You should use autoformat and then you can see the issues in your code.

This is really messed up:

      if (MashComplete == HIGH)
      {
        Serial.println("HIGH");

        if (MashComplete == LOW)
        {
          Serial.println("LOW");
        }

        if    (MashComplete == HIGH);
        {
          section = section + 1;
        }
        break;
      }

First of all, you will not hit the break unless MashComplete == HIGH otherwise it will fall thru to the next case.

Secondly, if MashComplete == HIGH why are you checking for MashComplete == LOW within that code block? You are also checking again for MashComplete == HIGH but you have a ; after the conditional so it is useless anyway.

5

The checking for the input to be low was just to see something over the serial port, it has to be high or low so ill get a result either way.

Thanks for the help

Pesh

6

Pesho77:
it has to be high or low so ill get a result either way.

I doubt it: it only tests for low when it already knows it's not....

7

It should be set low until the BSC460 sends a signal to set I high, the mash takes 1 hour to complete so it shouldn't do any thing till then, thats what im panning any way, so the serial port should show it as low till then.

I appreciate the code may be wrong which is why I asked for help.

Pesh

8

Here is my attempt to optimize and clean up the switch. You may find it helpful:

  switch (section) 
  {
    case 0: //////////// wait for mash to complete
      MashComplete = digitalRead(Pin); // Reading status of Arduino digital Pin
      if (MashComplete == HIGH)
      {
        Serial.println("HIGH");
        section = section + 1;
      }
      else
      {
        Serial.println("LOW");
      }
      break;

    case 1: // Start sparge
      openMLTFillValve();    //Open MLT fill valve
      //      delay(5000);
      section = section + 1;
      break;

    case 2: // set sparge rate
      Serial.println(spargeRate);
      Serial.println();
      Serial.println(MLTFillFlowRate);
      Serial.println();
      Serial.println(BKFillFlowRate);
      if (MLTFillFlowRate >= spargeRate  ) 
      {
        MLTFillValveOpenControl() ;
      }
      else
      {
        MLTFillValveCloseControl();
      }
      //  SpargeInterval = 120000;   // wait 2 mins
      //   SpargePreviousMillis = 0;
      if (SpargeCurrentMillis - SpargePreviousMillis > SpargeInterval) 
      {
        //openBKFillValve();
      } // Fill BK
      if (BKFillFlowRate >= spargeRate   ) 
      {
        BKFillValveOpenControl() ;
      }
      else 
      {
        BKFillValveCloseControl();
      }


      //      delay(5000);

      // Section added to time sparge for 1 hour

      S--;
      delay(1000);
      if (S < 0)
      {
        M--;
        S = 59;
      }
      if (M < 0)
      {
        H--;
        M = 59;
      }
      if (H < 0) 
      {
        H = 23;
        M = 59;
        S = 59;
      } 
      if (M <= 9)
      {
        Serial.print("0" );
      }
      Serial.print(M);
      Serial.print("  " );
      Serial.print ("\t");

      if (S <= 9)
      {
        Serial.print("0" );
      }
      Serial.print(S);
      Serial.print("  " );
      Serial.print("\t");

      if (H <= 9)
      {
        Serial.println ();
      }

      if (M == 0 && S == 0)
      {
        Serial.print ("stop");
        section = section + 1;
      }
    }
    break;
  }
9

It should be set low until the BSC460 sends a signal to set I high, the mash takes 1 hour to complete so it shouldn't do any thing till then, thats what im panning any way, so the serial port should show it as low till then.

Suppose I gave you a glass of liquid, and said "Taste this. If it's beer, go through door #1. If it's grape juice, go through door #2.". You taste it, and say "It taste's like weasel (DELETED). I say "Well, that's Budweiser, so go through door #1".

Would it make ANY sense for anyone in the room beyond door #1 to ask if you glass contains apple juice?

THAT is what your code is asking.