Help with RS232 input that uses stx/etx error in terminal

[alto777]

You could read

Serial Input Basics - updated

Updated Version Please note that this is a revised version of the advice in this earlier Thread which has become very long. As far as possible I have kept the code examples identical or simplifed them slightly. It should not be necessary to refer to the older Thread, but feel free to do so. Contents The following sections are in this Tutorial Introduction Serial data is slow by Arduino standards Example 1 - Receiving single characters Why code is organized into functions Exampl…

for a start. There's coverage of how to receive a message that is marked at the beginning and end as yours is.

This function

Serial.readBytesUntil() - Arduino Reference

might make short work of your task, or shorter anyway.

Check for availability and read single bytes by hand until you see an STX, which may be a real STX. Then read until you get the ETX or the readBhtesUntil() times out.

Some examination of the collected characters would confirm the reception of a true packet. Convert the eight or as many as 13 byte pairs that make up your data.

If you get ambitious, the checksum could be, um, checked.

a7