I want to operate my AVR from my PC, I mean that I want to send commands to do things.
The communication goes by serial. I start with ASCII and want to show the characters on a 44780 display. In ASCII some bytes are for control, but also every byte can be "displayable".
I started with finding out how Adobe defined there printer commands. But soon I learned that I want/need to do more then sending just characters to the display (like "printing"). First hurdle is the USART control.
So how to instruct my AVR to handle the byte as a number, a character or a device command.
Is it only a matter of definition? May be de C-people will laugh about my problem... (I use asm).
I am thinking of writing a line (some maximum characters 40, 64, 256?), and defining the first byte as a control byte. This control byte tells how the rest of the line is to be treated: just print/display every byte, execute commands for port reading, define some spreadsheet format for following data, and so on; even I can instruct not to expect a new control byte at the beginning of the next new line(s).
I am looking for guidance how to set it up (what are the usual definitions?). Are there standards? Is the first byte idea good? Or should it be at the end of line? Or do I have to take an entirely different approach?