Wiegand data and com port

[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.

[jmaloway]

Felch,

I went out today and got the PIC12F629 - but I have one question before I do anything... what programmer and software do you use to burn PICs? I was using Ponyprog 2000, but I have also tried IC-Prog which seems to have a much wider range of devices which it can program. Whenever you go to program a device, there are a multitude of options that you can choose, I beleive they are all for the oscillator. Which one should I use?

Thanks again,

James.