How to compare strings/array? RFID Project

[astanapane]

hi all again,

i try to see what the problem is.

I think there might be a problem on storing data to EEPROM of the pic16f628a...

and there also be a problem somewhere on the code...

Main:
high portb.3
low portb.1					    ' activate the reader
SERIN2 portb.1, 84, [WAIT($0A)] ' STR buf\12]	' wait for hdr + ID
high portb.1					' deactivate reader
pause 500
 
Check_List:
  FOR tagNum = 1 to 2				' scan through known tags
    FOR idx = 0 TO 11				' scan bytes in tag
    READ (((tagNum-1) * 12) + idx), char	' get tag data from table
    IF (char <> buf(idx)) THEN Bad_Char		' compare tag to table
    NEXT
    GOTO Tag_Found				  ' all bytes match!

when i try to pass the card from the reader it light the led of the reader but nothing happens to my LCD.

then i pass second time the card from the reader the led on the porta.3 light up and i get on my lcd the Error tag.

I dont understand what is happening on the first time that i pass the card. It doesnt do anything.

Why when i pass it two times i have bad tag on the display.

On other thing is that i cannot make it work to show me the name on the display on the right cards.

If you have any solutions please help me.

regards

[Archangel]

Just countin beans here:

buf        VAR    Byte(12)' RFID bytes buffer

I think should read

buf        VAR    Byte[12]' RFID bytes buffer

I am looking for other issues

[astanapane]

Thank you Joe,

i will make the change in the afternoon, then i will check and let you know.

Your help is much apreaciated.

Best Regards,

[astanapane]

i have changed the () with this [] but didnt work.

something else is the mistake and i cannot understand.

When i pass the tag from the reader doesnt do anything, but i pass it twice then i get the bad tag on the display.

It seems that doesnt recongise the tags i gave to the program.

somthing has to do with this line

SERIN2 portb.1, 84, [WAIT($0A), STR buf\10] 'the number 10 here is the 9600???

i cannot understand this line could you help?

FOR idx = 0 TO 11 ' here is it ok this line if my RFID tags have 12 digits?
READ (((tagNum-1) * 10) + idx), char ' this line is chineese to me. what is the number 10 in there? What number should i put if my RFID tags have 12 digits?

[Archangel]

i have changed the () with this [] but didnt work.

something else is the mistake and i cannot understand.

When i pass the tag from the reader doesnt do anything, but i pass it twice then i get the bad tag on the display.

It seems that doesnt recongise the tags i gave to the program.

somthing has to do with this line

SERIN2 portb.1, 84, [WAIT($0A), STR buf\10] 'the number 10 here is the 9600???

i cannot understand this line could you help?

FOR idx = 0 TO 11 ' here is it ok this line if my RFID tags have 12 digits?
READ (((tagNum-1) * 10) + idx), char ' this line is chineese to me. what is the number 10 in there? What number should i put if my RFID tags have 12 digits?

Working from memory here, my book is outside, and I am not dressed to go get it . . .
As I remember the 84 is the Mode setting the baud rate, the buff\10 sets the string state to 10 characters - 0 to 11 would equal 12 characters in your index, so I am thinking your buf\10 should be buf\12 . . .

[astanapane]

Hi Joe,

i would also like to specify that the tags i have there are manchester encoding. Do i have to decode it through the program in order to work?

I dont know how to decode it. As from the page here http://www.sparkfun.com/products/10169 these are the features
Features:

EM4001 ISO based RFID IC
125kHz Carrier
2kbps ASK
Manchester encoding
32-bit unique ID
64-bit data stream [Header+ID+Data+Parity]

From what you are saying now:

i have already change the buf/10 to 12 but nothing happens.

If you see the site in here http://melabs.com/resources/ser2modes.htm , there is a 4Mhz which i use at them moment.

There are several numbers in there included the 84. The number 84 seems to read the data at 9600.

Here is an other example of the code http://melabs.com/samples/PBP-mixed/ser2mod.htm

Serin2 pinin,396,[WAIT("F"), STR test8\8]

   Serout2 pinout,396,["14: ",STR test8\8,13,10]   ' 15: 7ZZ-0001

' Waits for the string "F", then collects the next 8 characters.  These are

' stored as ascii in 8 locations of the array variable test8.  The SerOut2

' statement uses the same modifier to send all 8 locations of the array

' variable as an ascii string.

   Serin2 pinin,396,[WAIT("Z",45), STR test8\8\"0"]

   Serout2 pinout,396,["15: ",STR test8\8,13,10]   ' 16: F7ZZ-

' This example demonstrates how you can put multiple characters in the

' WAIT.  It waits for the string "Z-", since the ascii code for "-" is

' 45.  The STR item is the same as above except we have added the stop

' character "0".  When it encounters "0" at the sixth character, it

' replaces it and fills the rest of the test8 array with null characters.
 
   Pause 2000

   Goto mainloop
 
   End

[Archangel]

I know little to nothing about manchester encoding, I defer to the More Experienced members here, Right now I am still recovering from a hard drive crash, having "unearthed" my computer, I cannot see my bench for the scattered "stuff" ;(, at least the computer is up, except all my PDFs are corrupted.