How to compare strings/array? RFID Project

[Bruce]

Are you sure you're programming your tag numbers in EEPROM at burn time? You should be
able to read back the .hex after programming to check.

[Robson]

Are you sure you're programming your tag numbers in EEPROM at burn time? You should be
able to read back the .hex after programming to check.

I don´t wrote the code before for storing on eeprom.

But maybe this could work

DATA @$00, $D7, $7C, $4B, $02, $2D, $C9, $80, $3A, $C4, $72

Loop    VAR BYTE
ReadTag VAR BYTE[2]
Tag     VAR WORD[5]
TmpTag  VAR BYTE[10]
ConvTag VAR WORD

' -----[ Program Code ]----------------------------------------------------

FOR Loop= 0 TO 9           ' Reading Data from EEprom Adr: $00 -$09
    READ Loop,TmpTag(Loop)
NEXT Loop

Main:

LOW PORTB.3 ' activate the reader
SERIN2 PORTB.2, T2400, [WAIT($0A,"100050"), STR ReadTag\2]
HIGH PORTB.3 ' deactivate reader

Check_List:

FOR Loop = 0 TO 8 STEP 2    ' Calculate Word from HighByte + LowByte
    Tag(Loop/2) = TmpTag(Loop)*$100+TmpTag(Loop+1)
NEXT Loop

ConvTag = ReadTag(0)*$100+ReadTag(1) ' Conversion of ReadTag to WORD

FOR Loop = 0 TO 4           ' Compare if ReadTag compares to Database in Eeprom
    IF ConvTag = Tag(Loop) THEN Tag_found
NEXT Loop
GOTO Bad_Char

Bad_Char: ' try next tag
'....
'....
GOTO main

Tag_Found:

Error corrected... Sorry

[dan-tron]

I have simplified my program to isolate the issue. I believe it lies with the READ command. This is my simplified code.

CMCON = 7   
DEFINE OSC 20

char            VAR     Byte                    ' character from table

' - LCD Stuff -
i con 254
clrlcd con 1
cgram con 64
ddram con 128
n96n con $4054
pause 1000
serout2 portb.7,n96n,[i,clrlcd]
pause 1

Tag1 DATA @$00,$10,$2A,$54,$FF,$7C

Main:

READ $02, char        ' get tag data from table

'Debug to LCD
serout2 portb.7,n96n,[i,clrlcd]
pause 500
serout2 portb.7,n96n,[i,ddram+0]
serout2 portb.7,n96n,[HEX char]
serout2 portb.7,n96n,[i,ddram+6]
serout2 portb.7,n96n,[DEC char]
pause 1000

end

At this point I am just trying to read a byte form the EEPROM and display it on the LCD just to prove it is being read. I see the EEPROM data in the EEPROM data window on my EPICWin programming software. So I guess it is writing the EEPROM data at burn time. However all I can debug on the LCD so far is just 0. This leads me to think that the problem is with the READ command. With the above example I would think that the LCD would display 2A or at least something other than just 0's.

[Darrel Taylor]

"Program/Verify Data" must be checked for it to write EEPROM data when programming.

<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1940&stc=1&d=118807518 2">
<br>

[dan-tron]

I already have the "Program/Verify Data" option checked. Also if I Read the chip after Programming it, I do see the EEPROM data present in the Data EEPROM window. So it's definitely writing to the EEPROM. It's just not reading it for some reason.

Also some other things I tried just now was switching to the internal 4MHz resonator and trying a second chip in case it was a bad chip. Neither made any difference.

[dan-tron]

Ok, get this! I just tried using a 16F84A instead of the 16F628A using nearly the exact same code and it works! I just removed the CMCON = 7 and DEFINE OSC 20 and stuck a 4MHz resonator on the board. With the 84A the LCD reads out the proper values one after the other, 10,2A,54,FF,7C. So now it looks like there is either something weird happening when I compile or the 628A does not like this code. Any ideas? I'd rather not have to step down my chip for this and have to order more old 16F84A's.

'CMCON = 7
'DEFINE OSC 20

char            VAR     Byte                    ' character from table
loop var byte

i con 254
clrlcd con 1
cgram con 64
ddram con 128
n96n con $4054
pause 1000
serout2 portb.7,n96n,[i,clrlcd]
pause 1

DATA @$00,$10,$2A,$54,$FF,$7C

Main:
for loop = 0 to 4
READ loop, char        ' get tag data from table

'Debug to LCD
serout2 portb.7,n96n,[i,clrlcd]
pause 500
serout2 portb.7,n96n,[i,ddram+0]
serout2 portb.7,n96n,[HEX char]
pause 1000

next
end

[Bruce]

Change this: READ (tagNum - 1 * 10 + idx), char ' get tag data from table

to this: (((tagNum - 1) * 10) + idx), char ' get tag data from table

Does it work now?