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Difference between these two IF statements

 
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bhas_r



Joined: 19 May 2009
Posts: 18

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Difference between these two IF statements
PostPosted: Mon Aug 29, 2022 9:32 am     Reply with quote
Hi all,

I am a little bit confused with the below statements:

IF ( (input (TNKH) == 1) && (input (TNKL) == 1) && (input (SUMP) == 0) )

IF ( (input (TNKH) == 1) & (input (TNKL) == 1) & (input (SUMP) == 0) )

I wrote the program from the above if statement I used the first one.

With one condition failing the loop executes and Motor always running.

I need all the inputs should be as equal to the value after the equal sign.

Looking for your great help to complete my project.

The program as below:
Code:

#include <Deena Wlc.h>

/*     

//OUTPUTS
RLY1   PIN_A0   //RELAY 1
SENPW   PIN_A1  //SENSOR POWER ENABLE OUTPUT
MON   PIN_A2    //MOTOR ON LED
//INPUTS                                             
TNKH   PIN_A3   //TANK HIGH INPUT
TNKL   PIN_A4   //TANK LOW INPUT                               
MAN   PIN_A5    //MANUAL SWITCH                         
//OUTPUTS
TNKFL   PIN_C0  //TANK FULL LED   
DRYRL   PIN_C1  //DRY RUN OR SUMP EMPTY LED
RLY2   PIN_C2   //RELAY 2                       
//INPUTS
STOP   PIN_C3   //STOP / RESET BUTTON           
SUMP   PIN_C4   //SUMP SENSOR INPUT                         
DRYR   PIN_C5   //DRY RUN INPUT                           
*/                                                                     
/*****************************************************************************/                                                       
unsigned INT8 mst, i;                   
void Autorun();                                           
void Manrun();                                     
                                     
/*****************************************************************************/
void main()             
{
   
   port_a_pullups (0xFF);

   WHILE (TRUE)
   {
      //TODO: User Code
      mst = read_eeprom (0);
      output_high (SENPW);
      delay_ms (2000);
                                   
      //Manual start
      IF (input (MAN) == 0)   
      {
         Manrun ();
      }

     
      IF (input (STOP) == 0)
      {
         mst = 0;
         write_eeprom (0, mst) ;
         output_low (DRYRL);           
         output_low (MON);
         output_low (RLY1);
      }
                                 
      //AUTO start
      IF (mst == 0)
      {
         IF ( (input (TNKH) == 0) && (input (TNKL) == 0))
         {
            output_high (TNKFL);
            //mst = 0;
         }

         else IF ( (input (TNKH) == 1) && (input (TNKL) == 0))
         {
            output_low (TNKFL);
         }

         else IF ( (input (TNKH) == 1) && (input (TNKL) == 1) && (input (SUMP) == 0) )
         {
            mst = 1;
            write_eeprom (0, mst) ;           
            Autorun ();                                           
            write_eeprom (0, mst) ;                   
         }                                         

         output_low (MON);
         output_low (RLY1);
         output_low (SENPW);
      } 

      else IF (mst == 1)
      {
         mst = 1;
         write_eeprom (0, mst) ;
         Autorun ();
         write_eeprom (0, mst) ;
      }

      else IF (mst == 2)
      {
         output_high (DRYRL);
         while (input (STOP) == 1);   
      }                               
                                         
     
      while ((mst == 3) && (input (STOP) == 1))
      {
         delay_ms (1000);             
         output_low (DRYRL);
         delay_ms (500);
         output_high (DRYRL);         
      }                       
         
      delay_ms (30000);
   }
}

/*****************************************************************************/
   VOID Autorun ()
   {
     
      output_high (SENPW);
      output_high (MON);
      output_high (RLY1);                                           
      //mst = 1;                     
     
      //Delay loop FOR dry running check
      FOR (i = 0; i <= 6; i++)
      {
         delay_ms (30000);                             
      }

      WHILE ( (input (DRYR) == 0) && (input (TNKH) == 1) && (input (SUMP) == 0)) ;

      IF (input (DRYR) == 1)
      {
         output_high (DRYRL);
         mst = 2;
      }                                       

     
      IF (input (SUMP) == 1)
      {
         output_high (DRYRL);
         mst = 3;
      }

      IF ((input (TNKH) == 0) && (input (TNKL) == 0))
      {
         mst = 0;
      }

     
      output_low (SENPW);
      output_low (MON);
      output_low (RLY1);
   }

   /*****************************************************************************/
   VOID Manrun ()
   {
     
      output_high (SENPW);
      output_high (MON);                             
      output_high (RLY1);
      mst = 1;
     
      //Delay loop FOR dry running check
      FOR (i = 0; i <= 6; i++)
      {
         delay_ms (30000);
      }
                 
      WHILE ( (input (DRYR) == 0) && (input (STOP) == 1) && (input (SUMP) == 0)) ;

      IF (input (DRYR) == 1)
      {                         
         output_high (DRYRL);     
         mst = 2;           
      }
               
      IF (input (SUMP) == 1)                   
      {
         output_high (DRYRL);
         mst = 3;
      }

      IF (input (STOP) == 0)
      {
         mst = 0;
      }

      output_low (SENPW);
      output_low (MON);     
      output_low (RLY1);
   }             

   /*****************************************************************************/

_________________
Thanks and Regards

R.Bhaaskar
Ttelmah



Joined: 11 Mar 2010
Posts: 19561

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PostPosted: Tue Aug 30, 2022 10:21 am     Reply with quote
& is 'bitwise and'. If you have two numbers, it generates the & of their
values. So:

1 & 3 gives 1

The result has the 1 where the same bit is on in both the values.

&& is 'logical and'.

It gives a TRUE only if the values given are logically TRUE.

Your original line will only execute it's associated statement if
all three tests are TRUE.

However I cannot see an 'else' for this statement that actually
stops the motor. Remember once it is on, it'll stay on till you turn it
off.
bhas_r



Joined: 19 May 2009
Posts: 18

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Thanks for the reply
PostPosted: Wed Aug 31, 2022 5:56 am     Reply with quote
As you said the motor always run till the while statement true.
Code:
WHILE ( (input (DRYR) == 0) && (input (TNKH) == 1) && (input (SUMP) == 0));

One mistake i made in my program is I used MCLR pin in use as input without disabling the MCLR in fuses.

So my input is not valid in the program. Kindly see the below header file.

I will recheck my program as soon as possible after disabling the MCLR
and i will update the result.

Once again thanks for the reply.
Code:

#include <16F676.h>
#device ADC=10

#use delay(internal=4MHz)
#use FIXED_IO( A_outputs=PIN_A2,PIN_A1,PIN_A0 )
#use FIXED_IO( C_outputs=PIN_C2,PIN_C1,PIN_C0 )
//OUTPUTS
#define RLY1   PIN_A0   //RELAY 1            CORR
#define SENPW   PIN_A1  //SENSOR POWER ENABLE OUTPUT     CORR             
#define MON   PIN_A2    //MOTOR ON LED          CORR   
//INPUTS
#define TNKH   PIN_A3   //TANK HIGH INPUT corr
#define TNKL   PIN_A4   //TANK LOW INPUT  corr
#define MAN   PIN_A5    //MANUAL SWITCH  corr
//OUTPUTS                                                 
#define TNKFL   PIN_C0  //TANK FULL LED             CORR                                       
#define DRYRL   PIN_C1  //DRY RUN OR SUMP EMPTY LED     CORR                                                   
#define RLY2   PIN_C2   //RELAY 2                           CORR                                 
//INPUTS
#define STOP   PIN_C3   //UNUSED NOW STOP INPUT    CORR
#define SUMP   PIN_C4   //SUMP SENSOR INPUT     corr
#define DRYR   PIN_C5   //DRY RUN INPUT            corr

_________________
Thanks and Regards

R.Bhaaskar
Ttelmah



Joined: 11 Mar 2010
Posts: 19561

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PostPosted: Wed Aug 31, 2022 9:37 am     Reply with quote
I think that will read as '1' all the time.
bhas_r



Joined: 19 May 2009
Posts: 18

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While statement
PostPosted: Wed Aug 31, 2022 10:10 am     Reply with quote
This is the program for water level controller.
When the water touches the High level sensor the input TNKH Senor reads zero.
Same for dry run and sump empty signal will goes to High.

Then while statement will read zero and loop will break.
After that IF statement writes the value to mst variable.
Depending upon mst variable valve, error or motor stops.
_________________
Thanks and Regards

R.Bhaaskar
bhas_r



Joined: 19 May 2009
Posts: 18

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My code is working
PostPosted: Fri Sep 02, 2022 12:47 am     Reply with quote
Happy to tell

My code is working as expected.
Soon i will post my full code.
_________________
Thanks and Regards

R.Bhaaskar
Ttelmah



Joined: 11 Mar 2010
Posts: 19561

View user's profile Send private message

PostPosted: Mon Sep 05, 2022 1:15 am     Reply with quote
As a comment, the key I suspect here is to check that values are actually
arriving and readable by the pins you try to use.
Always worth simply not trying to do the actual control, but instead write
a basic debug program that shows what each pin is reading, and test this
before trying to code the logic.
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