[fpc-pascal] Reading Serial Hex Data

[Marco van de Voort]

Op 12/27/2020 om 4:47 PM schreef James Richters via fpc-pascal:
> I'm trying to figure out how to read a packet of HEX Bytes of an unknown
> length that have no specific termination character over a serial port as
> efficiently as practical.
> The packet ends when there is just no more data to read.
>
> I have something that is working that I wrote using SerRead from the Serial
> unit in FPC, and it works at 9600bps,
> but the method I am using will not work well at anything higher unless I can
> figure out how to a very accurate very short delay.
> At 9600, I need a delay just a little less than 1ms, so I use Sleep(1) for
> my delay, but since 1ms is the minimum for sleep, and sleep
> itself is not really that accurate, I am doing a lot more delay than I need
> to in order to make sure it works.

You don't mention OS, but for Windows no sleep should not be necessary, 
and is unnecessarily delaying.

Look at delphi tcomport which has a waitforevent based solution.