[SOLVED] Comparator on PIC16F628A

[speedEC]

Dear All,

I need some help on solving comparator issue on PIC16F628A. I have used Hi-Tech C compiler. I have not enabled GIE and since I have not used interrupt isr. This is the code that works fine.

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Code C - [expand]
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main(){
  . // setting interrupts
  .
  .
  .
  while{
      if (RBIF){
      .
      .
      .
      }
      if (INTF){
      .
      .
      .
 
      }
      BATT_LOW_LED = !BATT_STATUS_HIGH; // If C2OUT Low then Lit LED
            
      CMCON; // read CMCON 
      CMIF = 0; // clear Comparator Flag
      CMIE = 1; // Enable Comparator Interrupt
      delay_ms(1000);
    
    SLEEP();
  }
}

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But, The following code not works. I don't know why?

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Code C - [expand]
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main(){
  . // setting interrupts
  .
  .
  .
  while{
      if (RBIF){
      .
      .
      .
      }
      if (INTF){
      .
      .
      .
 
      }
     
      if (CMIF != 0){
          BATT_LOW_LED = !BATT_STATUS_HIGH; // If C2OUT Low then Lit LED
            
          CMCON; // read CMCON 
          CMIF = 0; // clear Comparator Flag
          CMIE = 1; // Enable Comparator Interrupt
          delay_ms(1000);
      }
    SLEEP();
  }
}

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Thanks

 

[upand_at_them]

Is your compiler optimizing the "CMCCON;" statement away? Create a dummy variable and assign CMCON to it to be sure.

 

[speedEC]

Hi upand_at_them,

Thank you for response. I have tried as you suggested but till not works.

 

[speedEC]

I have introduced ISR and enable GIE. Now everything works fine. thanks