kbhit with get_string problem

[ShellTox]

Hello


I'm trying to send some commands to a PIC18F4550 through RS232. At this point I'm able to send the commands and capture them in the PIC, but I'm using get_string to do this. I have other things to do while I'm waiting for the commands, but the program hangs in get_string.
I think I could solve this problem if I had the hardware UART free, but unfortunately it's being used for other peripherals. So I'm using a software UART.

My question is: Is there a way to solve this problem without using the #int_rda, only available with the hardware UART?

I've tried to use kbhit() with get_string, but apparently this idea doesn't solve the problem, because I can only receive the commands sometimes.

[Ttelmah]

Multiple parts:
You can, if you have the pin available, use the conventional 'INT_EXT', as an interrupt to trigger the start of receiving a character on the software UART. A search here will find a lot about this.
Even the hardware UART, will have the same problem, using get_string. Get_string, _waits_ for a complete string. Get_string, is not 'rocket_science', it's source is in input.c, and is only about ten lines long. Rewrite this, to check kbhit, before retrieving a character, use global or static variables, to store the string, and a separate flag, to say that the string is complete. Then you can perform your other tasks, till the flag sets.

Best Wishes

[ShellTox]

Thank you for your advices Ttelmah and quick answer

Fortunately I have a free external interrupt pin just beside my rx pin.
I'm going to see the source code of get_string. If I can solve this problem I'll give some feedback.

[asmboy]

here is a link to code that does work pretty much as you want - that had useful input from TTelmah and PCM prgrammer -


http://www.ccsinfo.com/forum/viewtopic.php?t=38922&highlight=

[ShellTox]

Thank you for your replies


It's indeed a very useful link, with very good ideas.