Redirecting serial data at runtime

[Charles Linquis]

I wrote an enormous program that has an awful lot of RS-232 text out (and user response IN). Now I need to send and receive that data to the second (hardware) serial port - sometimes. I can't possibly have double the number of routines for I/O (one for HSERIN1/HSEROUT1 and another set for HSERIN2/HSEROUT2) ,the extra code wouldn't fit. I'm using an '8723.

I'm pondering trying to write a new assy routine with the function of HSERINx/HSEROUTx where "x" is the port I want to send/receive data from at the moment. Before I even attemp such a feat, I was wondering if anyone else has tried this or knows a simple way.

[rmteo]

Wow, that is some application to have used up 128K device. The largest app that I have managed ended up being just under 36K. It include a 240x128 GLCD, touchscreen, 4x4 keypad, SD card storage with FAT filesystem, UART comms, etc.

[Charles Linquis]

Yes, I have been "up against the wall" program space wise for quite a while. I have been begging MChip for a 256K part - because I could really use it. No luck so far.

[Archangel]

Hi Charles,
Would it work to use 2 PICs, one to run the program and the other as a display server, where it only has to fetch from program space or eeprom the strings and display them ? At least you would get your 256k. You could drive them both from and EXT OSC so they would clock together.

[Charles Linquis]

It would work - but it would require a lot of recoding. Unfortunately, my code doesn't have the outgoing strings in arrays. That would make life a lot easier and I should do that some day.

I have managed to compact the code to fit in 119K. Believe it or not, that gives me a fair amount of "breathing room", since all the little code blocks have been written, and now I can just call them up when I need something new.

If I could just get that elusive "Hserinx/Hseroutx" routine running it would solve a whole bunch of trouble. It looks like I'm going to have to modify PBPPIC18.LIB - AGAIN!

[rmteo]

I don't think you will ever see anything larger than 128K (they do go up to 256k with the 24-bit core) in a PIC18. Probably has to do with die size. Since you are using a 80-pin device, could you possibly use external program memory in the extended microcontroller mode to get up to 2MB of program space?