🚀 go-pugleaf

>Confirm Ed's first guess: check rather the LCD and your software than the
>pc. You do nothing special with the com port, so if that wouldn't work,
>Windows would have to write off the serial interface as such.
>
>What kind of LCD are you using? I have never heard about one with an asynch
>serial interface. You probably have a third-party add-on controler board,
>and these are all but reliable. And probably you are not just reading but
>have to write a bytes to request reading. Are you sure you are syncronized
>between writes & reads? The 250ms read cycles, is at a request by LCD specs
>or is that just what you have seen as result?

Its a:
http://www.crystalfontz.com/products/633/index.html

>Anyhow you should open the port in async mode, set its (internal) buffers
>and both write & read having set the timeout structure.
>Then every supposed write/read sesions should:
>- clear Tx buffer and Rx buffer
>- write request in one go (with timeout), not char by char as the LCD could
>timeout.
>- check tx-buffer empty flag,
>- read n characters with timeouts.

Yup... this is what im doing.
Although, im not quite sure what the timeout values should be.