PIC to PC data transfer + Keystrokes

[lilimike]

I want to design a hardware/software application and I would like to get some ideas from you people.

The situation is:
I have a PC at the entrance of a production floor and each employee (15) must enter his username and password to clock-in and again to clock-out when they leave.

What I want to provide:
To give an RFID tag to each employee, tags will be listed on a database with user credentials. They will just walk-in the shop and show their tag to the reader.

The issue I have:
The clock-in / clock-out is provided by a remote Web application and unmodifiable so the end product will need to just send a userame + TAB + password + CRLF.

What I've done so far:
Pretty much searching and reading...
The RFID scanning part is all good and I am comfortable enough with PICs.
I started looking at the PS/2 keyboard protocol but I think I can only send keystrokes in that way and since I need a way to get to the database to get the credentials I need a 2 way data exchange. From what I've read RS232 would be simpler than USB but either way I need to figure out a way to access the database, get the user info and send the keystrokes without disturbing the web page. I figured I could include a flash memory and hold the database on my device but I still need a way to get the info to the flash memory in a user-friendly way.

At this point I am open to any and all opinions.

Mike

 

[Pommie]

I would just send the RFID via RS232 to the PC. On the PC have a program to lookup the ID and, assuming you can't modify the existing program, use something like sendkeys to get the data to it.

If you want to stick with the pic route then choose an 18 series chip and you will have enough memory to hold a large number of IDs. As the program space is flash memory it can be used to store your IDs. The data can be entered by having a learn mode entered via a hard coded RFID tag and then write any seen tags to the flash memory. Or, put a keypad on it to enter a code etc.

Mike.

 

[lilimike]

Your first suggestion is better I think, I would probably have issues with adding the user credentials within the PIC using the learn mode.

Thanks for your reply,

Mike

 

[lilimike]

After looking at all the possible ways, I believe my best route would be to go USB since serial ports are fading out on the new technologies and after looking at Microchip µCs with USB integrated it looks simple enough.

I've looked at the 18 series but I have some restrictions and using the Microchip Advance Part Selector, setting the following filters:
8-bit
USB connectivity
max 28 pins SOIC
2 x I²C
None of the resulting products have any non volatile memory so I will add an external EEPROM.

What I plan to do is to communicate with the PC via USB, design some software to manage up to 15 users and all the data will reside on the EEPROM for portability.

I am now looking at the 18F25J50
PIC to PC and vice versa communication via USB
PIC to EEPROM via I²C
RFID to PIC using an available I/O pin (Manchester code)
I selected to have a second I²C on the PIC for future use either in case I find a cheap RFID module that can communicate in this way or to interface multiple box via wireless.

The data stored is:
RFID tag = 14 Characters
Name =30 Char.
User ID = 15 Char.
User Password = 15 Char.
for 15 users I get a total of 1,110 bytes of data

My understanding is that an 24LC16B (16Kbit) will provide 16 x 1024 bits / 8 = 2KB of space.

If I am going the wrong way, please someone let me know...

Mike