The rest is brainstorming... merge to somewhere around CommMatrix?
As RS232 serial ports are disappearing from notebooks (but USB-RS232 can work, except the megatune is somewhat broken, like it cannot handle com5), in the future other communication methods might be addressed:
- it is likely that we move max232 to the cable (maybe on all ARM boards, and smaller boards, and anything designed in the future). We can have just 3.3V serial onboard (like all cellphones, 4 or 5 pins depending on weather we want to export 5V too or only 12V) and make small boards that live in cable housing
- with MAX232 to connect to RS232
- PL2303 (or some FTDI) to connect to USB
- some will want to use CAN (=>USB, or otherwise) anyway, for reason
- Theoretically the parallel port (programmer cable) could also be used to communicate with the board (serially), although this would be a large overhead on the PC.
- PS2 http://panda.cs.ndsu.nodak.edu/~achapwes/PICmicro/PS2/ps2.htm (surprising, but would require no hardware, just software, and would be a solution to many people, not big overhead on MSAVR) [AVR313 Atmel Appnote has working code for the PS2 keyboard to AVR direction]
- Ethernet http://www.lantronix.com/products/eds/xport/index.html
- Ethernet http://www.embeddedethernet.com/appnotes/EmbEth.html
- USB http://hc08web.de/usb08/ (I had luck with an $18 USB-RS232 converter cable in a local store)
- USB to RS232-ttl converter to be used instead of MAX232 .. with a pair of fast opto coupler ??.... -> http://www.ftdichip.com/index.html