How to compare strings/array? RFID Project

[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.

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

[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 -

    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:

    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}

[CSU_2010]

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.

'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]

[mister_e]

try with SEROUT2 and use the STR modifier.

[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:

'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

[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?

[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.

[astanapane]

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.

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

[RFEFX]

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:

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

[astanapane]

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,

[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.

[Archangel]

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.

[astanapane]

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.