Wiegand data and com port

[Felch]

Hi!

Serial string "ID xxxxxx" is output on GPIO0 if GPIO1 is at high level (enable pin). Taking GPIO1 low will disable output. Output speed is 4800 bd.
If you mix up D0 and D1, data will still be output but card number will be wrong.

I have the same code working at 16F628 too. It really requires only minimal changes.

I will "release" a newer version on reader code now (should be attached). Late program had problems with certain types of readers: it did not read anything. Present code fixes it. One more bug is fixed.

About OSCCAL (calibration data). My serial output (bit-banging) routine (actually not mine, I guess mr. Myke Predko wrote it) relies on chips internal oscillator. It's frequency must be exactly 4MHz or receiving computer will fail to read stream. Microchip has made PIC's internal osc's frequency adjustable by means of changing one conf byte - the OSCCAL. It has been set in factory to some (correct) value. When you burn chip, it will get a new value from the .HEX file. This must be avoided. I am not sure about PonyProg but most PIC programmers now about that trick and ask user for the right value. Programmer can read it from chip and then, after burning code, restore it.

Happy PICing!
/Felch

[jmaloway]

Thanks,

I think I'm starting to get a better grasp on how this works.

When you say that GPIO1 (pin 7) must be high, you just mean not connected to ground, right? Or does it have to be connected to +5V?

Thanks for the updated code, I really appreciate it.

I don't know what the frequency of the chip that I have is, I've uploaded and downloaded from it countless times, but I don't know if it's ever actually done anything. Can I just use an external Xtal? I have a bang-on 4.000 Mhz one right here.

Thanks again,

James.

[Felch]

GPIO1 must be connected to +5V, preferably via 1k resistor. Since there is an internal pull-up resistor in PIC, you may also leave this pin floating. You can comment checking this pin out from code if you don't need it. My application needed disabling reader.
Likewise you may change code to implement external xtal oscillator. X-tal can be connected to GPIO5&4 only but since GPIO3 and 2 are free, you can do this. You will need a pull-up for GPIO3 (it does not have internal one.

[jmaloway]

Ok, I think I understand the method to the madness, but...

One thing I don't understand and haven't been able to get any info about on the net is which pins on the PIC the GPIO pins are - are they the RA or the RB pins, and is the numbering the same?

My other question is... why is the oscilator not connected to pins 15 & 16? I though that since those were the "OSC" inputs on a PIC, that they were the only pins that you could attach a Xtal to. And to recap quickly, it's supposed to be running @ 4.000Mhz, right?

Thanks again,

James.

[Felch]

PIC16F628 has 16 i/o pins which are divided into 2 groups - ports. They are PORTA and PORTB. naturally they have different pin numbers! Powerful PICs have more ports (18f452 up to PORTE). PIC12F629 has only 6 pins and they are named GPIO0...GPIO5.
Abbout xtal connection: what code are you talking about? proximity.asm works on pic12f629 which does not have pins 15 and 16!? And the code relies on internal oscillator, no xtal!
dbl_rdr on the other hand works on 16f628 (or analogous). There xtal must be connected to pins 15&16. If u use other chip, pin numbers will be different. Of course xtal can be connested only to dedicated pins. That's true with every microcontroller.

Proximity.asm runs at 4MHz.

[jmaloway]

Ok, I think I get it now.

I am going to head over to my parts supplier tommorow and pick up a PIC12F629.

When I get the chip, I'm supposed to get the OSCAL value by doing an upload from the chip and then choosing to use the value from the chip, right?

Then, once I get "proximity.asm" loaded onto the chip, the pin connections should go as follows:

Pin 1: +5V DC
Pin 2: Prox reader "Data 0"
Pin 3: Prox reader "Data 1"
Pin 4: No Connection
Pin 5: No Connection
Pin 6: No Connection / +5V
Pin 7: RS-232 Data out
Pin 8: Ground

No crystal is needed as the oscillation is taken care of by the internal oscillator.

Is this correct? :-)

Thanks again,

James.

[Felch]

Yep. That's correct.

[robrien]

Serial string "ID xxxxxx" is output on GPIO0 if GPIO1 is at high level (enable pin). Taking GPIO1 low will disable output. Output speed is 4800 bd.

I've been carefully trying to decipher your code and am quite pleased I seem to be following most of it, however, when I examine your send_rs232 routine, it looks to me like it only outputs "ID xxxx". i.e. 4 digits - not 5 as one might expect (00000 - 65535). Am I missing something?

[hansol]

im' try create circuit with RFIDlock.zip and not work
if pic not programed voltage pin GP0 = 0V
if pic it's pogramed with RFIDlukk.HEX (winpic) voltage pin GP=5V continus
what is wrong

scuse my primitive englese

[mackrackit]

Welcome hansol.

It helps others to help you if you post your code. (and configuration settings) The schematic is great but...

[hansol]

code adn reader is ay-k12 rosslare(wiegand 26 bit)

[mackrackit]

Hi,

My ASM is very rusty, but after rereading this thread I think the answer , or at least your problem is addressed starting at post #18.

Sorry I can not be more help.