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C/C++ > Possibility of programming the link port

#125776 - spencer723 - Mon Apr 16, 2007 11:08 pm

I've been looking at documentation and everything and I've noticed that most of the link port use is for the Xboo cable. I know the Xboo cable uses a parallel port but I've found schematics that converts the link port to a standatd RS232 serial cable. Now, what I'm wondering is, is it possible to send terminal characters like you would a regular COM session to another serial port through the link port? What I want to do is send characters to an IFI robotics robot controller but I would just like to know if it is possible and if it is, how? Thanks in advance

#125792 - tepples - Tue Apr 17, 2007 2:00 am

spencer723 wrote:
I've found schematics that converts the link port to a standatd RS232 serial cable. Now, what I'm wondering is, is it possible to send terminal characters like you would a regular COM session to another serial port through the link port?

Yes. One of the GBA serial port modes is "UART mode", which operates at Dreamcast-compatible levels (0.0 V to 3.3 V) but can be linked to a serial port that uses RS-232 levels (-12 V to 12 V) through level shifters.
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#125794 - spencer723 - Tue Apr 17, 2007 2:25 am

tepples wrote:
spencer723 wrote:
I've found schematics that converts the link port to a standatd RS232 serial cable. Now, what I'm wondering is, is it possible to send terminal characters like you would a regular COM session to another serial port through the link port?

Yes. One of the GBA serial port modes is "UART mode", which operates at Dreamcast-compatible levels (0.0 V to 3.3 V) but can be linked to a serial port that uses RS-232 levels (-12 V to 12 V) through level shifters.


So if I can shift the voltage up to -12-12V I can use it as a regular serial cable link? Now, on to the programming aspect. Would I just use the functions declared in the xcomms.h header file in libgba? For example, to send a character through would I use dprintf("value");? To read the incoming transmission would I use dfread();? Or are there more complicated instructions needed to initiate terminal communication?