Changing declared variables names on the fly

[jessey]

Hello,

This is probably a dumb question but is there a way using PBP to have a variable with-in a declared variable name? Its a little hard to explain exactly what I mean but it would be sort of like this:

You want to print a variable name to your Lcd so you print:
LCDOUT $FE,1,"On_Timer_Hour",DEC M," "

the On_Timer_Hour would be your declared variable and the variable with-in it would be the M variable. Setting the M variable before the print to the Lcd (or in your code) would change the variable name displayed to the Lcd. So the variable On_Timer_Hour could be On_Timer_Hour1, On_Timer_Hour2, On_Timer_Hour3 ect. ect.. It would be great if I could implement that concept in my code. Wishful thinking?

Why I'm asking is: I'm writing a timer program where the user can programme 10 different On and Off times that repeats every 24 hours using Darrels ELASPED.PBP. I have in excess of 100 variables that all have a numerical value at the end of the variable name. If it is possible to use a variable with-in a declared variable name then it would save a lot of code space.

In each of the 10 timer sections (I'd like to have more if I can gain more code space) I have intermediate dummy variables that all have to be set then re-set to implement my code. It would be great if I could just change one M variable that would change them all. There's a lot I don't understand about programming, like array variables with a variable index or other concepts that could make writing code more efficient. What is the concept of a variable index? Would that have anything to with what I'm trying to accomplish here?

Is it possible or just wishful thinking.

Thanks
jessey

[sayzer]

Hi Jessey,


It seems you really need to use array.

Since you need 10 different ON times and 10 different OFF times, 20 variables would give you a lot of headache if not using array.

But, if I got it right, then a simple code as below could be the idea for you, may be.

EEPROM 1,[1,2,3,4,5,6,7,8,9,10,101,102,103,104,105,106,107,108,109,110]
'Say these are your stored alarm time(s).
'1 to 10    : ON time
'101 to 110 : OFF time

OnTime  var byte
OffTime var byte
Index   var byte
Hour    var byte
Alarm   var PORTB.0  'A relay is connected here to wake you up!


'Hour variable gets its value from RTC routine somewhere in the code....


Start:


    FOR Index = 1 to 10
    
        READ Index , OnTime       'Read stored ON  time.
        READ Index +100, OffTime  'Read stored OFF time.
        IF Hour = Ontime  THEN ALARM = 1 'Check if there is a match with the current time. If yes, turn ON the relay.
        IF Hour = Offtime THEN Alarm = 0 'Check if there is a match with the current time. If yes, turn OFF the relay.
    
    NEXT Index 


GOTO Start

Hour variable is just an example. Assuming you get your hour variable somewhere in the code. It could be the minute, the second, the day, year etc... or all of them together.

Say you stored the "Alarm ON" time in the eeprom location 1. Then its corresponding "Alarm OFF" time should be stored in a sequenced number, for example +100, 101.

This way you can have an array to make more and more variables to match. Use a simple code as above first to start understanding the idea.

[jessey]

Hello Sayzer,

Thanks for answering my question. Forgive my ignorance but I'm not familiar with your code example or how to implement it. I am familiar with how to read & write to the eeprom, for a byte variable I use

EEPROMData0 VAR BYTE
U VAR EEPROMData0
READ 0, EEPROMData0

to write I use:
EEPROMData0 = U
Write 0, EEPROMData0


then for a word variable I use

EEPROMData1 VAR WORD
V VAR EEPROMData1
Read 1, EEPROMData1.byte0
Read 2, EEPROMData1.byte1

to write I use:
Write 1, EEPROMData1.byte0
Write 2, EEPROMData1.byte1

In your example code I don't know how I would write to locations 1 to 10 and 101 to 110 of the eeprom address location 1? Could you please explain the concept as I'm not sure how to do that. I can sorta understand your Index loop but I don't see any relationship between the Index variable and the EEPROM 1, [1,2,3......] statement? I've seen the EEPROM 1, [1,2,3......] statements in some of the code examples in the archives but I just don't understand the concept.

Could you educate me about how this works?

Thanks
jessey

[sayzer]

...locations 1 to 10 and 101 to 110 of the eeprom address location 1?..
jessey

1, 10 or 101 or 110 these are all already EEPROM locations. So there is no access to "10 of location 1". 10 is the location.

For the index example,

when index=1, take a look at the following code.

READ Index , OnTime
READ Index+100, OffTime

Lest put "1" in index variable and re-write these two lines again.

READ 1, OnTime
READ 1 + 100, OffTime

Now, the third time, this will become as follows.

READ 1, OnTime
READ 101, OffTime

With these two lines, you will read EEPROM location 1 and store the location content in Ontime variable. And, read EEPROM location 101 and store the location content into OffTime variable.

Now, you can take a look at FOR loop above and think about incrementing index variable. When index variable changes, the eeprom location that we read also changes.

Any question there?

[jessey]

Hi Sayzer,

Thanks for your explanation about the For-Next loop, I think I can grasp the concept of the Index For-Next loop now but what I don't understand is how do I write the values to the different eeprom locations. I added some push buttons to your code to try and increase and decrease the OnTime & OffTime variables and the Hour variable in an attempt to flash an Led but can't get it to work. Could you please help me to understand how to write to the different eeprom locations?

Thanks
jessey

'Pic18f452-20/P

Increase_OnTime_Push_Button VAR PORTD.2    '(pin 21)  2nd  
Decrease_OnTime_Push_Button var PORTB.0    '(pin 33)  3rd  
Increase_OffTime_Push_Button var PORTB.1   '(pin 34)  4th                 
Decrease_OffTime_Push_Button var PORTB.2   '(pin 20)  5th  
Change_On_Off_Time_Push_Button VAR PORTD.1 '(pin 35)  6th  
Led VAR PORTA.1                            '(pin 3)
Buzzer VAR PORTC.2                         '(pin 17)

OnTime  var byte
OffTime var byte
Index   var byte
Hour    var byte
HOUR = 0

Is_Pressed con 0
Is_Not_Pressed con 1      

EEPROM 1,[1,2,3,4,5,6,7,8,9,10,101,102,103,104,105,106,107,108,109,110]

GOTO MainLoop

Change_On_Off_Time:
    PWM Buzzer,250,1
    WHILE Change_On_Off_Time_Push_Button = Is_Pressed : PAUSE 100 : WEND
Loop:
    IF Increase_OnTime_Push_Button = Is_Pressed THEN 
       OnTime = OnTime + 1 : PWM Buzzer,250,1 
       WRITE 1, OnTime
    ENDIF

    IF Decrease_OnTime_Push_Button = Is_Pressed THEN
       OnTime = OnTime - 1 : PWM Buzzer,250,1 
       WRITE 1, OnTime
    ENDIF
                                   
    IF Increase_OffTime_Push_Button = Is_Pressed THEN
       OffTime = OffTime + 1 : PWM Buzzer,250,1 
       WRITE 101, OffTime
    ENDIF

    IF Decrease_OffTime_Push_Button = Is_Pressed THEN
       OffTime = OffTime - 1 : PWM Buzzer,250,1 
       WRITE 101, OffTime
    ENDIF

    IF Change_On_Off_Time_Push_Button = Is_Pressed THEN
      PWM Buzzer,250,1
      WHILE Change_On_Off_Time_Push_Button = Is_Pressed : PAUSE 100 : WEND
      RETURN
    ENDIF

       LCDOUT $fe,1,"OnTime  = ",dec Ontime
    LCDOUT $fe, $c0,"OffTime = ",dec OffTime 
    PAUSE 100
goto Loop


MainLoop:
    IF Change_On_Off_Time_Push_Button = Is_Pressed THEN GOSUB Change_On_Off_Time

   'Hour variable gets its value here......
    IF Increase_OnTime_Push_Button = Is_Pressed THEN 
       Hour = Hour + 1 : PWM Buzzer,250,1 
    ENDIF

   'Hour variable gets its value here......
    IF Decrease_OnTime_Push_Button = Is_Pressed THEN
       Hour = Hour - 1 : PWM Buzzer,250,1 
    ENDIF

       LCDOUT $fe,1,"Hr=",dec Hour," OnTime=",dec Ontime
    LCDOUT $fe, $c0,"OffTime = ",dec OffTime

    PAUSE 100

    FOR Index = 1 to 10
        READ Index , OnTime            ' Read stored ON  time.
        READ Index +100, OffTime       ' Read stored OFF time.
        IF Hour = Ontime  THEN Led = 1 ' If yes, turn ON the relay.
        IF Hour = Offtime THEN Led = 0 ' If yes, turn OFF the relay.
    NEXT Index 
GOTO MainLoop
END

[mister_e]

WRITE will work at run-time
EEPROM or DATA will work at Programming time


DATA @101,10 will write 10 at address 101 at programming time
WRITE 101,10 will write 10 at adress 101 at run time

i will read-back the whole post here, but it think you already understand the concept... OR i'm too drunk ... no way!