Problem with saving to EEPROM...

Hello Everyone,

PLEASE GO TO THE 3RD POST DOWN FOR A CLEARER POST OF WHAT I AM HAVING A PROBLEM WITH!

I am working on a delay project which uses 2 buttons one for increasing the delay and one for decreasing the delay. I am using the PIC16F84 and have a button connected to PORTB pin 5,6. LED on PORTB 3,4,7 and PORTA pin 3.
PORTB pin 4 is for showing the length of the delay, pin 3 for showing when both buttons are pushed that it saves the delay to EEPROM, 7 for showing when IncreaseButton is pushed, and PORTA pin 3 for when DecreaseButton is pushed.

The problem I am having is when I program the PIC16F84 it is starting at a delay of what I believe to be 30s when it should be 15s. This is according to this line:

data word (0),(1500) 'Save 1.5s delay to EEPROM at programming

Also, it doesnt seem that the buttons are changing the delay. What I dont understand is that everything worked until I added this above line.

Here is the code that I am working on:

''Increase/Decrease Delay with Buttons

Delay var word 'Declare Variables
x var word
IncreaseButton var PORTB.5
DecreaseButton var PORTB.6

data word (0),(1500) 'Save 1.5s delay to EEPROM at programming
read 0, Delay.BYTE0 'Save value in EEPROM to delay
Read 1, Delay.Byte1

Loop:

high PORTB.4 'Turn LED on
low PORTB.3 'Turn on LED from "saving" delay

for x = 1 to Delay 'For loop to run delay/ Allows button to be
'read without interrupt
pause 1 'Pause 1 ms

if IncreaseButton = 1 then 'When IncreaseButton is pressed
high PORTB.7 'Turn LED on to show button is pushed

pause 50 'Pause for 50 ms

if DecreaseButton = 1 then'If both buttons pushed then write delay
write 0, Delay.BYTE0 'to EEPROM
write 1, Delay.BYTE1
high PORTB.3

SetDelayCycle1:

'Loop to wait until buttons are released before going on
if DecreaseButton = 0 or IncreaseButton = 0 then
goto Loop 'Restart the delay
else
goto SetDelayCycle1
endif

endif
Delay = Delay + 500 'increase delay
if Delay => 30000 then 'If delay is equal to or greater than 30 sec
Delay = 30000 'then keep delay at 30 sec max delay
pause 100 'If at max delay length flash LED
low PORTB.7
pause 100
high PORTB.7
endif

IncreaseButtonCycle:

'Loop to wait until button is released before going on
if IncreaseButton = 0 then
LOW PORTB.4 'Turn LED off
pause 500 'Pause to show LED off before restarting delay
low PORTB.7
goto loop 'Restart the delay
else
goto IncreaseButtonCycle
endif
endif

if DecreaseButton = 1 then 'When DecreaseButton is pressed
high PORTA.3
pause 50 'Pause for 50 ms

if IncreaseButton = 1 then'If both buttons pushed then write delay
write 0, Delay.BYTE0 'to EEPROM
write 1, Delay.Byte1
high PORTB.3

SetDelayCycle2:

if IncreaseButton = 0 or DecreaseButton = 1 then
goto loop 'Restart the delay
else
goto SetDelayCycle2
endif

endif
Delay = Delay - 500 'decrease delay
if Delay <= 500 then 'If delay is equal or less than 0.5 sec then
Delay = 500 'keep delay at 0.5 sec min delay
pause 100
low PORTA.3
pause 100
high PORTA.3
endif

DecreaseButtonCycle:

if DecreaseButton = 0 then
low PORTB.4 'Turn LED off
pause 500 'Pause to show LED off before restarting delay
low PORTA.3
goto loop 'Restart the delay
else
goto DecreaseButtonCycle
endif
endif

next x

low PORTB.4 'Turn LED off after full delay cycle
pause 500 'Pause to show LED off before restarting delay

goto loop 'Restart the delay (Infinite Loop)
end 'End of program

This probably is not a very efficent piece of code, but it was doing the job until I tried doing the DATA command. I tried using different values other than the 1500 such as.. 100, 500, 3000 and all of the values were causing the same thing to happen with a delay of what I believe to be 30s the max delay that I have for the piece. I also tried the EEPROM command with the same conclusion. Any help would be appreciated.

Thanks,
Michael

Tear,

the DATA statement doesn't work that way, see PBP Manual section 5.11

I guess you can't expect someone to help you any further with the "spaghetti"-code you have posted, because it is "unreadable"

It is no surprise that one gets lost with this kind of code.

In addition:

some CRLF in your posting would have increased readabiltiy dramatically.

Hi,

After more testing I have found out that using the DATA and EEPROM command are not writing the value to the EEPROM. Below is test code to see if the value I want to place in EEPROM is written to it. Unfourtantly it doesnt work and doesnt work with any value. Looking at the manual it said that you need to do the READ and WRITE command in seperate bytes since I am using words to hold values larger than 255.

Here is the example code:

Delay var word

EEPROM 0, [1500]
read 0, Delay.BYTE0
Read 1, Delay.BYTE1

if Delay = 1500 then
goto loop
else
goto Flash
endif

Flash:
high PORTB.3
pause 500
low PORTB.3
pause 500
goto flash

''Start of program!
Loop:
'Run program

No matter what number I try to use for the EEPROM command the light will always go to the flash loop saying that it isnt reading the same value.

~Michael

again:

the DATA statement doesn't work the way you are using it, see PBP Manual section 5.11

the EEPROM statement doesn't work that way either, see PBP Manual section 5.18

DATA WORD 1500
would do the trick.

OR: split your word into two bytes and use:

DATA @0,$DC,$05
(Attention, LowByte is first in this example!)

If you want the HighByte first you have got to swap the Byte order in your READ and WRITE statemenst as well.

B.T.W.
you could make your life a lot easier by moving to a more up to date PIC like the 16F628 or 16F88 (which is Loader compatible!) or one of the many others...

...you could get rid of the external Resonator (or Crystal with it's Caps)

Another thing I have seen in your code example is:
your Buttons appear to be active HIGH, means you have got to have PullDown resistors at the corresponding PIC Pins.

If you would reverse this logic you could even get rid of these resistors and use the PICs internal weak pullups.

Sorry for reposting the same thing. I read the manual and even though PICBasic makes it a lot easier for coding I am not strong at it at all. 99% of my experience as a student is in building circuits (just finished my sophmore year of EE).

I have one question though, if you dont mind. Using DATA WORD 1500 works, but I am guessing that it places it at memory slot 0 of the EEPROM. How can I place another variable like this after the first one? I am sure that I need to includethe address in the command somehow.

Thanks,
Michael

Quote:

Originally Posted by Tear

I have one question though, if you dont mind. Using DATA WORD 1500 works, but I am guessing that it places it at memory slot 0 of the EEPROM. How can I place another variable like this after the first one? I am sure that I need to includethe address in the command somehow.

OK,
we are talking about the DATA statement.
It preloads the EEPROM at program time.

If you want to specify a location (other than the current pointer position) there is only one choice:
use DATA @Location,Byte1,Byte0.......

There is NO way of specifying a location (other than the current pointer position) a WORD is to be written to.

But this is not much of a problem, since the WORD is written to the location starting from the current pointer position.
(Bear in mind, a WORD is written LowByte first!)

So:

DATA @0,$11,$22
DATA WORD $AABB
DATA $33
DATA $44
DATA WORD $CCDD

would result in the following EEPROM content:
11 22 BB AA 33 44 DD CC

Just try it !

However,
I would always use DATA with Bytes (since READ and WRITE only deal with Bytes), because later on in your program is a lot easier, you don't, have to remember wether or not you have to swap the order of the two bytes you have just "READ".