Example : if calibra (value for memory, set by user) is 140, the heating start at 137.
I wrote the routine for display those two values : w1 (current temperature) and calibra. The led blink ( PWM out) only when w1 < ( (calibra-3) !
Code:
if mode = 2 then
 call poz
 char = 16
 call    PrintChar  
 calibra = vt
                LcdReg  =  %10000000 + 25        ' cursor  X
                call    PrintCtrlLcd
                LcdReg  =  %01000011 + 1         ' cursor  Y
                call    PrintCtrlLcd
'~~~~~~~~~~~~~~~~~ now display results 
 if (vt dig 2) <1 then
                char = 16  
                call Printchar
                else         
                Char = (vt dig 2)            
                call    PrintChar 
 endif      


                Char = (vt dig 1)           
                call    PrintChar                     
 
                Char = (vt dig 0)           
                call    PrintChar

                Char = 16                 
                call    PrintChar
            
                Char = 13
                call  PrintChar
               
                Char = 14
                call  PrintChar

                Char = 16                 
                call    PrintChar

                Char = 15                 
                call    PrintChar
endif