TCP/IP stack questions with the ENC28J60.

[FBeauch]

Greetings, I am a student in electronic engineering.

I am trying to make a centralised access control system where an Ethernet LAN will connect automated doors to a server.

I am also doing a bit of research on Ethernet controlers themselves. So far i've run into the ENC28J60 which I have studied extensively. But I still have some questions.

My first question is, with microchip's TCP/IP Stack, what kind of transfer rate could I acheive with a PIC18LF2620. I am pretty certain it would be more than enough for most applications i'm thinking about, I'm simply asking out of curiosity.

My other question is that, how easy is it to add modules to the µC containing the stack code? I was thinking of making a module similar to the TCP example and simply use it as a reference for adding modules, then put my code into it.

Also, since I plan to use a lot of the µC's power for tasks such as real-time sensor monitoring, user interface via keypad and LCD as well as an encryption routine to send info to the server. How will the stack affect the responsiveness and performance of the program? Is it better to simply use another PiC for all the peripherals and use the PICLF2620 only for transmitting via the ENC26J60?

Any advice would be apreciated.

Thanks in advance.

[arunb]

The modular approach, where several PICs are used to do different jobs is better, but this could be expensive as each module will have power supply unit, an interface for communication etc.

But with above approach you test each module individually..

thanks
aa

[eskimobob]

[FBeauch]

What I decided to do is simply use another PiC for the peripherals and use a standard serial link between it and the "EtherPic". The Pic interfaced to the ENC28J60 will simply relay the characters that arrive from the serial and redirect them to a TCP socket.

As for power supply I needed a 5v supply for other devices such as an RFID card reader and an LCD so I would have needed a 3.3v and 5v power anyways. I will use a 5v supplied PIC and won't need to deal with logic level conversion between it and the peripherals. I will only have to deal with the 2 Serial lines between the 2 Pics.

Thanks again for answering.

[arunb]

One PIC is connected to the ENC28J60;works on 3.3 V voltage level, while the other PIC connected to the peripherals works on 5 V voltage level.

With the above setup, both PICs cannot communicate using serial interface as voltage levele are different..

Am I right here ??

thanks
arunb