RF ID Urgent Help Needed

[Bakuko]

im having problems interfacing an RF ID and PIC16F877..

the tag uses 125kHz 64bits of code

here's the problem:

tho i have known what the code the card has, i dont know how to catch it.. we just tried to connect it to a computer then run notepad then use the tag.. then we got the code the card has.. but in a PIC i cudnt get it.. im having trouble CATCHING the code.. i know its serial.. it uses a clock..

can you guys help me?
can you give me a crash course on this?

thanks

 

[Papabravo]

How can we help you when you provide so little information? I'm not sure if your problem is hardware or software. That you have it working on a PC with notepad(?) is very nearly irrelevant.

 

[penoy_balut]

the codes are not sent as it is, mostly it's Manchester coded and have to be decoded in your receiver

 

[Papabravo]

Another one time poster. Heavy sigh....

 

[Bakuko]

How can we help you when you provide so little information? I'm not sure if your problem is hardware or software. That you have it working on a PC with notepad(?) is very nearly irrelevant.

i connected it to a computer.. used a serial connector.. so that i could retrieve the data from the cards.. thats what the guy(the person where we got the reader) told us to do to retrieve what code the card contained.

i think im having problems with the understanding of the reader's output.. because the guy said it is ascii so i researched about it.. it seems that more confusion came.. i dont know where to start.. i really dont know much..

 

[philba]

You need to understand the reader. Just saying "serial" doesn't help much and makes you out to be lazy or evasive.

You have to understand the data rate, stop and start bits, parity or not. I would suggest you either go back to the "guy you got it from" or find the model number/manufacturer and google for that. If it's a commercial unit, there WILL be some sort of information about it.

You've probably spent more time asking for help than it would take to actually go and find it yourself.

One clue for you, though - the format of the card will probably not have it fields align on byte boundaries. You will need to take the received bytes, break them down into bits and look for the fields that way. often times different cards use the bits differently. I had to do this with an HID reader I used in a project.

 

[Bakuko]

You need to understand the reader. Just saying "serial" doesn't help much and makes you out to be lazy or evasive.

You have to understand the data rate, stop and start bits, parity or not. I would suggest you either go back to the "guy you got it from" or find the model number/manufacturer and google for that. If it's a commercial unit, there WILL be some sort of information about it.

You've probably spent more time asking for help than it would take to actually go and find it yourself.

One clue for you, though - the format of the card will probably not have it fields align on byte boundaries. You will need to take the received bytes, break them down into bits and look for the fields that way. often times different cards use the bits differently. I had to do this with an HID reader I used in a project.

i guess so.. ill go do that..