How to compare strings/array? RFID Project

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- 25th August 2007, 00:17
dan-tron

How to compare strings/array? RFID Project

I am trying to make an RFID reader using Parallax's RFID Reader Module and a PIC 16F628A.
I am using PBP and am having troubles figuring out how to convert over the sample code found at Parallax to work in PBP.
Sample code: http://www.parallax.com/dl/src/prod/RFID1.BS2

The main trouble I am having is getting the comparison to work. I'm not sure what the best way would be to compare the scanned RFID 10 byte string array against a set of known tags.
Below is the part of the code I believe is not working right.
Does anybody have any idea on what I can do to fix this or perhaps someone has a better way of doing it? Thanks in advance!
-Dan

' -----[ EEPROM Data ]-----------------------------------------------------
Tag1 DATA "100050D77C" ' valid tags
Tag2 DATA "1000504B02"
Tag3 DATA "1000502DC9"
Tag4 DATA "100050803A"
Tag5 DATA "100050C472"

' -----[ Program Code ]----------------------------------------------------
Main:
LOW portb.3 ' activate the reader
SERIN2 portb.2, T2400, [WAIT($0A), STR buf\10] ' wait for hdr + ID
HIGH portb.3 ' deactivate reader

Check_List:
FOR tagNum = 1 TO LastTag ' scan through known tags
FOR idx = 0 TO 9 ' scan bytes in tag
READ (tagNum - 1 * 10 + 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!
Bad_Char: ' try next tag
NEXT
- 25th August 2007, 02:46
Darrel Taylor

Try using 396 instead of T2400 in the SERIN2 statement.

Constants like T2400 are only for SERIN (without the 2).
<br>
- 25th August 2007, 11:25
dan-tron

No luck. I replaced the T2400 with 396 and it made no difference. I don't believe that the serial input is the problem because I can debug with a serial LCD and I can get it to print the actual RFID tag numbers on the LCD. The problem seems to lie under Check_List:. Specifically the line...
READ (tagNum - 1 * 10 + idx), char ' get tag data from table

I've never saved anything to EEPROM before. Maybe its not reading it correctly? Or saving it?
- 25th August 2007, 12:35
Robson

Can you post your complete code?
I have to understand what are you´re trying to do.

regards Rob
- 25th August 2007, 14:12
dhouston

You might try using WRITE to store the data. That might isolate the problem to your DATA or READ statements.
- 25th August 2007, 14:41
Robson

Maybe this one will help you.
I don´t try before working with SERIN2 but give it a try. You can change this part with storing data to eeprom too. It´s only to see how to realize that, if i´m not wrong.
To store data on eeprom use
DATA @$00,$D7,$7C,$4B,$02,$2D,$C9,$80,$3A,$C4,$72

Code:

Loop VAR BYTE ReadTag VAR BYTE[2] ConvTag VAR WORD Tag VAR WORD[5] Tag(1) = $D77C Tag(2) = $4B02 Tag(3) = $2DC9 Tag(4) = $803A Tag(5) = $C472 ' -----[ Program Code ]---------------------------------------------------- Main: LOW PORTB.3 ' activate the reader SERIN2 PORTB.2, T2400, [WAIT($0A,"100050"), STR ReadTag\2] HIGH PORTB.3 ' deactivate reader Check_List: ConvTag = ReadTag(0)*$100 + ReadTag(1) FOR Loop = 1 to 5 IF ConvTag = Tag(Loop) THEN Tag_found NEXT Loop GOTO Bad_Char Bad_Char: ' try next tag '.... '.... GOTO main Tag_Found:
- 25th August 2007, 15:15
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.
- 25th August 2007, 16:49
Robson

Quote:

Originally Posted by 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.

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

But maybe this could work

Code:

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
- 25th August 2007, 20:51
dan-tron

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

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.
- 25th August 2007, 21:55
Darrel Taylor

1 Attachment(s)

"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>
- 26th August 2007, 00:11
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.
- 26th August 2007, 00:34
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.

Code:

'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
- 26th August 2007, 02:01
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?
- 26th August 2007, 09:07
dan-tron

EUREKA!
Thanks guys! You have been a huge help. I have finally figured it out.
My problem was more like 3 problems...

1. I have never done EEPROM stuff before so I was lost to begin with.
2. As Bruce pointed out, the mathematical order of operations in one line was not correct. I guess the BS2 thinks a little differently from PBP in that respect.
3. My PicBasic Pro compiler was Version 2.30 form 2000. It seems that v2.30 supports the PIC 16F628 but the PIC 16F628A was implemented in a later version. I have upgraded my PBP to version 2.47 and now the EEPROM features work correctly on the 16F628A. When I successfully tested a 16F84A using the same code, that lead me to question the compiler.

So for future generations and the benefit of other people like me, here's my WORKING code that is tested successfully on a PIC 16F628A with a 20MHz resonator compiled using PBP v2.47. It reads data from the Parallax RFID Reader Module, compares it against known values stored in EEPROM and allows or denies access accordingly. Enjoy.

Code:

CMCON = 7 DEFINE OSC 20 'Set oscillator in MHz ' -----[ Variables ]------------------------------------------------------- buf VAR Byte(10) ' RFID bytes buffer tagNum VAR Byte ' from EEPROM table idx VAR Byte ' tag byte index char VAR Byte ' character from table ' -----[ EEPROM Data ]----------------------------------------------------- Tag1 DATA "100050A4B7" Tag2 DATA "1000508E0A" Tag3 DATA "10005091DC" Tag4 DATA "100050203A" Tag5 DATA "100050DA36" ' -----[ Initialization ]-------------------------------------------------- HIGH portb.3 ' turn off RFID reader LOW portb.6 ' lock the door! Low portb.4 'Turn off LED ' -----[ Program Code ]---------------------------------------------------- Main: LOW portb.3 ' activate the reader SERIN2 portb.2, 396, [WAIT($0A), STR buf\10] ' wait for hdr + ID HIGH portb.3 ' deactivate reader Check_List: FOR tagNum = 1 to 5 ' scan through known tags FOR idx = 0 TO 9 ' scan bytes in tag READ (((tagNum-1) * 10) + 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! Bad_Char: ' try next tag NEXT Bad_Tag: tagNum = 0 FREQOUT portb.5, 1000 */ $100, 115 */ $100 ' groan PAUSE 1000 GOTO Main Tag_Found: HIGH portb.6 ' remove latch High portb.4 ' Light LED FREQOUT portb.5, 2000 */ $100, 880 */$100 ' beep LOW portb.6 ' restore latch Low portb.4 ' LED OFF GOTO Main
- 26th August 2007, 12:46
Bruce

The BASIC Stamp solves math problems in the order they are written; from left to right. The
result of each operation is fed into the next operation. So to compute -

Code:

12 + 3 * 2 / 5 ...the BASIC Stamp goes through a sequence like this: 12 + 3 = 15 15 * 2 = 30 30 / 5 = 6

Unlike the BASIC Stamp, the PBP Compiler performs all math operations in full hierarchal
order. This means that there is precedence to the operators.

Multiplies and divides are performed before adds and subtracts, for example:

Code:

12 + 3 * 2 / 5 ...PBP goes through a sequence like this: 3 * 2 = 6 multiply first 6 / 5 = 1.2 divide second (the .2 is lost) 12 + 1 = 13 add last

Forcing the addition first with parenthesis like: (12 + 3) * 2 / 5 would return the correct
result. Good stuff to remember when porting BASIC Stamp code over to PBP.

I haven't played with a BASIC Stamp in years, but once I looked in the Stamp editor help
file under PBASIC Operators, it was obvious. I'm glad you got it working. Looks like a
fun project.

Maybe you could post your final version in the code examples section? Could save someone
else using the Parallax RFID components with PBP a lot of head-scratching...;o}
- 20th November 2008, 18:31
CSU_2010

RFID troubles

I know I'm resurrecting a dead thread here but I've searched and can't quite find what i'm looking for. I'm using a Parallax RFID reader and a PIC 16F88, with a 4 line LCD. Right now I'm just trying to get the tag ID's to display on the LCD. So far I can get the RFID to turn on and read a tag, but the information sent to the display is cryptic. I would appreciate any help you might be able to give. Thanks!

Here's the code I have so far.

Code:

'RFID and LCD test DEFINE OSC8 OSCCON=%01110000 ANSEL=0 led VAR PORTB.3 'led rx VAR PORTB.0 'Serial input from RFID reader lcd VAR PORTB.5 'Serial Output to LCD rfid VAR PORTB.1 'Enable rfid low= on buf VAR BYTE(10) 'Tag code stored as word Pause 1000 High rfid High led Pause 1000 Low led SEROUT lcd,0,[$FE,1] SEROUT lcd,0,[$FE,1,"Test"] Pause 4000 High led Pause 3000 Low led low rfid SERIN2 rx,396,[Wait($0A ),STR buf\10] High rfid High led Pause 2000 Low led Pause 500 SEROUT lcd,0,[$FE,1] SEROUT lcd,0,[$FE,1,"Tag number"] SEROUT lcd,0,[$FE,$C0,buf]
- 20th November 2008, 18:36
mister_e

try with SEROUT2 and use the STR modifier.
- 20th November 2008, 19:20
CSU_2010

Thanks, I tried SERIN2 and SEROUT 2, the LCD is still displaying weird symbols. It displays eveything else ok. Here's the code:

Code:

'RFID and LCD test 'Author Joshua Reynolds 'November 20th, 2008 'Rev. 1 'Configuring the 16F88 chip DEFINE OSC 8 'Internal Oscillator set to 8mhz OSCCON.4=1 OSCCON.5=1 OSCCON.6=1 ANSEL=0 'Turns off A/D converter '------Define I/O pin names rx VAR PORTB.1 'Serial input from RFID reader rfid VAR PORTB.2 'Enable rfid low= on led Var PORTB.3 lcd Var PORTB.5 buf VAR BYTE(10) 'Tag code stored as word '------Declare Variables key_value Var BYTE 'code byte from the keypad High led Pause 1000 Low led '------Wait .5 sec for everything to power up Pause 500 loop: SEROUT lcd,0,[$FE,1] SEROUT lcd,0,[$FE,1,"Read tag"] low rfid serin2 rx,396,[str buf\10] high rfid High led Pause 500 low led Pause 500 High led Pause 500 low led SEROUT lcd,0,[$FE,1,"One"] Pause 4000 SEROUT lcd,0,[$FE,1,"Tag Number"] Pause 2000 SEROUT2 lcd,396,[$FE,$C0,STR buf\10] Pause 5000 Goto loop End 'End of main program
- 20th November 2008, 19:25
mister_e

Try something, start a new code, fill the buf Array with some data (ASCII character), then send it to your LCD.

Any link for your RFID reader?
- 20th November 2008, 19:30
mister_e

Maybe not a bad idea to connect the RFID to your PC to see what happen... you'll need a MAX232 or any other level converter to do that.
- 20th November 2008, 19:48
mister_e

Just curious to know if the following line work with your LCD

Code:

SEROUT2 lcd,396,[$FE,$C0,"2nd Line???"]
- 21st November 2008, 01:39
CSU_2010

Thanks for the replies, I'll try it out in lab tomorrow. Here's a link to the RFID Parallax RFID
I'll have to look up the stuff on attaching it to a computer, I've never done anything like that.
- 25th November 2008, 01:28
CSU_2010

I'm trying to find out the RFID tag ID by reading the tag and displaying it on an LCD and I can't seem to figure it out. Has anyone else been able to display the tag ID on an LCD?
- 21st April 2010, 17:27
ScaleRobotics

RFID reader for cheap

I was at Radio Shack yesterday, trying to buy a breadboard. (No of course they didn't have it, why would my store have it in stock?)

Anyway, I was searching their bins and I saw a Parallax RFID READER WITH TAGS part number 276-0032, or this part: http://www.parallax.com/Store/Sensor...%2cProductName

It didn't have a price marked, so I had the lady scan it, and she told me it was $19.97. It's on my receipt as the correct part number, and correct product description. That's half off of Parallax's price, so if you are interested in RFID, you might want to check it out at Radio Shack.
- 22nd April 2010, 11:34
Ioannis

At their site they do not list it though...

Ioannis
- 9th December 2010, 09:26
RFEFX

Video of working RFID Project + uOLED

i thought id post it here.. since this thread helped in the trick math operation.

My Board runs a PIC16F877A @ 20Mhz

Video Here

Code:

define OSC 20 ADCON1=7 CMCON=7 LastTag CON 3 X VAR byte tagNum VAR byte ' from EEPROM table idx VAR Byte ' tag byte index char VAR Byte ' character from table buf var byte(10) '***************************************************************** SYMBOL PWRLED = PORTB.2 'Software controlled power LED SYMBOL RFID = PORTC.5 'RFID /ENABLE '***************************************************************** Tag1 DATA "0415146D53" ' 2 cards registered... Tag3 DATA "30700D48A5" '***************************************************************** HIGH PWRLED HIGH RFID PAUSE 1000 serout2 PORTC.0,84,[$55] ' uOLED Initialize '***************************************************************** Reset: gosub cls PAUSE 1000 '***************************************************************** Main: LOW rfid ' activate the reader SERIN2 PORTC.4,396,[WAIT(10),str BUF\10] ' wait for hdr + ID HIGH rfid ' deactivate reader Check_List: FOR tagNum = 1 TO lasttag FOR idx = 0 TO 9 READ (((tagNum - 1) * 10) + idx), char 'The Tricky Order of Operation IF (char <> buf(idx)) THEN Bad_Char NEXT GOTO Tag_found Bad_Char: NEXT Bad_tag: FOR x = 1 TO 2 serout2 PORTC.0,84,[$73,$6,$4,$0,$F0," ACCESS",$00] 'cmd,column,row,font,Color(msb:lsb),“string”,$00 serout2 PORTC.0,84,[$73,$6,$8,$0,$F0," DENIED",$00] NEXT PAUSE 4000 GOTO reset Tag_Found: for x = 0 to 2 serout2 PORTC.0,84,[$73,$6,$4,$0,$1F," ACCESS",$00] 'cmd,column,row,font,Color(msb:lsb),“string”,$00 serout2 PORTC.0,84,[$73,$6,$8,$0,$1F," GRANTED",$00] next pause 4000 GOTO reset CLS: FOR X = 0 TO 2 serout2 PORTC.0,84,[$45] next return
- 9th December 2010, 10:08
Ioannis

I wonder why you send the uOLED data 2 or 3 times in a loop.

Ioannis
- 9th December 2010, 17:57
RFEFX

Ahh yess the LCD refresh

In another post someone stated about lag issues with this particular uOLED from 4Dsystems They introduced Pauses, but i found out (through trial and error) that just sending the data a couple times in a loop (refreshing) rather than putting pauses in the the display code resolved any Lag issues. As you can see in the video it displays what im sending
to the display quite nicely and even before the RFID LED can change color.. I also dont read any ACK from the display, as it is not necessary and just slows down the process.

Cheers!
- 10th December 2010, 09:38
Ioannis

I see. OK, thanks.

What is you opinion about the display? (colors, brightness, sharpness).

Ioannis
- 10th December 2010, 16:03
RFEFX

uOLED-128-G1 Opinion

Overall the display is great. you have full control over any text you send to the display: positioning (x,y), Color(msb:lsb), and even font size. you can even make custom bit mapped color characters and store them on a uSD card. Or even tell the uSD to run a script.

cmd,column,row,font,Color(msb:lsb),“string”,Termin ator ($00)

My next goal is to have the PIC play a video from the uSD card. the only obsticle i see is you have to know a lot of information about memory structure, like sectors and such, to address the uSD card. here is the video command info:

Command ext_cmd, cmd, x,y,width, height, colourMode, delay, frames(msb:lsb), SectorAdd(hi:mid:lo)

- ext_cmd 40(hex) or @(ascii) : Extended Command header byte
- cmd 56(hex) or V(ascii) : Command header byte
- x : Video horizontal start position (top left corner).
- y : Video vertical start position (top left corner).
- Width: Horizontal size of the video-animation.
- Height: Vertical size of the video-animation.
- ColourMode 08(hex) : 256 colour mode, 8bits/1byte per pixel. 10(hex) : 65K colour mode, 16b/2B per pixel .
- Delay : 1 byte inter-frame delay in milliseconds.
- Frames: 2 bytes (big endian) total frame count in the video-animation clip.
- SectorAdd : 3 bytes (big endian) sector address of a previously stored videoclip that is about to be displayed.
- 11th December 2010, 14:36
Ioannis

From the pdf that are available, I could not find the specs for the video files.

What files the LCD can play?

Ioannis
- 11th December 2010, 22:46
RFEFX

I got it

Hey Ioannis,

I got video to play on the display from the PIC..

once i get the project up and complete ill write a tutorial on the process.
- 12th December 2010, 21:10
Ioannis

Okie, looking forward...

Ioannis
- 14th December 2010, 08:03
RFEFX

Re: I got it

Ioannis,

The video Tutorial On the 4Dsystems OLED is located in the Code Example section. link below.

Displaying Videos and Images on 4Dsystems uOLED Serially
- 28th March 2011, 10:42
astanapane

Re: How to compare strings/array? RFID Project

Quote:

Originally Posted by dan-tron

EUREKA!
Thanks guys! You have been a huge help. I have finally figured it out.
My problem was more like 3 problems...

1. I have never done EEPROM stuff before so I was lost to begin with.
2. As Bruce pointed out, the mathematical order of operations in one line was not correct. I guess the BS2 thinks a little differently from PBP in that respect.
3. My PicBasic Pro compiler was Version 2.30 form 2000. It seems that v2.30 supports the PIC 16F628 but the PIC 16F628A was implemented in a later version. I have upgraded my PBP to version 2.47 and now the EEPROM features work correctly on the 16F628A. When I successfully tested a 16F84A using the same code, that lead me to question the compiler.

So for future generations and the benefit of other people like me, here's my WORKING code that is tested successfully on a PIC 16F628A with a 20MHz resonator compiled using PBP v2.47. It reads data from the Parallax RFID Reader Module, compares it against known values stored in EEPROM and allows or denies access accordingly. Enjoy.

Code:

CMCON = 7 DEFINE OSC 20 'Set oscillator in MHz ' -----[ Variables ]------------------------------------------------------- buf VAR Byte(10) ' RFID bytes buffer tagNum VAR Byte ' from EEPROM table idx VAR Byte ' tag byte index char VAR Byte ' character from table ' -----[ EEPROM Data ]----------------------------------------------------- Tag1 DATA "100050A4B7" Tag2 DATA "1000508E0A" Tag3 DATA "10005091DC" Tag4 DATA "100050203A" Tag5 DATA "100050DA36" ' -----[ Initialization ]-------------------------------------------------- HIGH portb.3 ' turn off RFID reader LOW portb.6 ' lock the door! Low portb.4 'Turn off LED ' -----[ Program Code ]---------------------------------------------------- Main: LOW portb.3 ' activate the reader SERIN2 portb.2, 396, [WAIT($0A), STR buf\10] ' wait for hdr + ID HIGH portb.3 ' deactivate reader Check_List: FOR tagNum = 1 to 5 ' scan through known tags FOR idx = 0 TO 9 ' scan bytes in tag READ (((tagNum-1) * 10) + 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! Bad_Char: ' try next tag NEXT Bad_Tag: tagNum = 0 FREQOUT portb.5, 1000 */ $100, 115 */ $100 ' groan PAUSE 1000 GOTO Main Tag_Found: HIGH portb.6 ' remove latch High portb.4 ' Light LED FREQOUT portb.5, 2000 */ $100, 880 */$100 ' beep LOW portb.6 ' restore latch Low portb.4 ' LED OFF GOTO Main

hello all,

i would like to see the schematic of the above code if it is possible.

One more thing that i would like to incude at the code is to identify the name of the target id.

For example, once you pass the RFID chip from the reader, on the display to give you the name of the carrier.

if i have a chip with a target id : 123456789012 then i would like once i pass it from the reader to give a name like ASTANAPANE.

I guess that on the code i have to corespond the name to the target id.

How can we do that.

I have bought the modules from SPARKFUN and the RFID chips also from them.

I would like to make a small project for my room.

thanks for any suggestions.

Best Regards
- 29th March 2011, 09:23
RFEFX

Re: How to compare strings/array? RFID Project

Quote:

Check_List:
FOR tagNum = 1 to 5 ' scan through known tags
FOR idx = 0 TO 9 ' scan bytes in tag
READ (((tagNum-1) * 10) + 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!
Bad_Char: ' try next tag
NEXT

whenever the PIC identifies a tag stored in the EEPROM it still holds onto the "tagNum" variable. from there you can have your program branch off with the "tagNum" variable to display whatever you want. for argument sake lets say your third RFID badge is yours then:

Code:

Tag_Found: IF tagNum = 3 then displayName GOTO Main displayName: Serout2 portc.0,84,["ASTANAPANE"] 'assuming your display is on portc.0 @ 9600 baud pause 5000 'Pause 5 sec then clear display gosub CLRLCD Goto main

Hope this helps... Cheers
- 29th March 2011, 11:45
astanapane

Re: How to compare strings/array? RFID Project

thank you very much for the help....

i ordered the reader and the ID-12 from SPARKFUN, and i wait for them next week. Once i get them i will start to built my project.

I will make schematics and PCBs and i will post them here.

A lot of thanks for the code. I only need a little bit help of the code you made corresponding to the schematic.

If you dont have time i will read the code and identify the Pins for the pic16f628.

thank you very much again for your help.

I dont see the time to have the reader and the rfid chips with me.

Kind Regards,
- 29th March 2011, 14:54
astanapane

Re: How to compare strings/array? RFID Project

i have also one more question please.

I need to use the ID-12 with a display also. Can i use the pic16f628a to run both?

thank you very much.
- 29th March 2011, 17:06
Archangel

Re: How to compare strings/array? RFID Project

Quote:

Originally Posted by astanapane

i have also one more question please.

I need to use the ID-12 with a display also. Can i use the pic16f628a to run both?

thank you very much.

Go read your manual about LCDOUT, it explains in a thorough treatise exactly how to do that. I am perceiving this to be a school project, and it would be rather easy to hand you the code, I think that would do you more harm than good.
What you learn here you can then teach to someone else, that is how this forum works, a great many of the members ARE engineers, others are just interested hobbyist, and IF you are a student, as I believe, I do not want to enable you to fail and NO I do not mean fail the class. Write your code, Make the mistakes, Show us the mistakes, and receive help.
- 29th March 2011, 18:36
astanapane

Re: How to compare strings/array? RFID Project

sorry Joe.

i dont want to start that with student or not. If you think that i'm a student you might be right.

A student that is graduated from E.E.E. and i didnt like it then gradueated with MSc DATA COMS with Distinction and i only know to do CISCO. If someone will ask me about cisco i will help him with all my stength and examples.

Sorry i didnt like a lot my first degree thats why i dont know how to use programming very well.

Right now i;m working for a reseller company of Stratasys which makes the FORTUS RP systems.

I only want to make a small project for my father's home.

I'm not a programmer or student sorry....i just do not have enouph time to spend on this.

I will try by my self and i will ask for your help.

thanks.

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