🚀 go-pugleaf

Hi!

I am coding a multi-player game that allows the connection between two
PC machines using a serial connection. I am having a problem with
interrupted RS-port output, perhaps you can help?

I have coded many programs to use interrupt-driven input from COM ports,
but now I decided to try also the interrupt-driven output to speed up
my game. My routine works quite well a little while, but then the UART
just simply stops giving 'free-to-transmit' interrupts. I have not yet
figured out why. Perhaps there is a bug in my code (probably), but I
would like to know if I am doing something wrong.

What should one do if one gets the 'free-to-transmit' interrupt from
UART but one has nothing to send? Currently I send a null character and
mask this interrupt off inside my IRQ handler. Then when I again have
something to send I re-enable the interrupt. Is this the correct way
to do it? What happens if I just ignore the 'free-to-send' interrupts
when I have nothing to send? Does the UART generate this interrupt
again after a while, or what? Is the interrupt-driven output commonly
used, and is it reliable?

Thanks in advance for any help you can provide me.

Patrick Aalto
ap@tukki.jyu.fi