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Fazecast / jSerialComm

Platform-independent serial port access for Java
GNU Lesser General Public License v3.0
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Different serial port reading behaviour between 2.9.3 and 2.10.1 with non-standard 76800 baud rate on Ubuntu #502

Closed NorbertSandor closed 1 year ago

NorbertSandor commented 1 year ago

I use jSerialComm on Win11 and Ubuntu. For a very basic test, I send the 0, 1, 2, ..., 7 bytes from an Arduino Mega to the PC with baud rate 76800.

The situation is the following:

Maybe do you have an idea what may cause this? Thanks.

NorbertSandor commented 1 year ago

Wow, if I switch to baud rate 9600 or 115200, it works on Ubuntu as well :\ I found this related discussion: https://stackoverflow.com/a/65208850/306047

What I don't understand is how was it possible that it worked with 2.9.3? :|

hedgecrw commented 1 year ago

That's odd - this would be a pretty significant regression. The only changes that were made (about baud rate) between the two versions was a unification of the "parameters" and "flow control" native blocks so that some of the settings didn't get clobbered on random distros. Let me do a quick code review of the commits and see if anything obvious jumps out to me. Just for sanity check...are you seeing this issue on ALL baud rates over 9600 on Ubuntu, or just specific ones (like 76800)?

NorbertSandor commented 1 year ago

115200 works as expected both on Win11 and Ubuntu, only the not-too-standard 76800 seems to be problematic (of what I tried). Don't put much time in it, I will use 115200. (But if you decide to do so I can supply logs or whatever you need.) + thanks for the prompt response :)

hedgecrw commented 1 year ago

Since you have a real-world way to test this, I'd love to actually get this bug resolved properly. Could you please test the latest 2.10.2-SNAPSHOT version and see if it resolves the issue on Ubuntu (specifically with the non-standard 76800 baud rate). The 2.9.3 (and previous) versions had one way of addressing this issue, but it caused bugs on some OSs. The 2.10.1 resolved those bugs but apparently messed up custom baud rate handling. I've tried to make some changes here that fix both issues without re-introducing the bugs that 2.10.1 was meant to solve:

SNAPSHOT Version: 2.10.2-SNAPSHOT SNAPSHOT Direct Download Link SNAPSHOT Instructions

hedgecrw commented 1 year ago

Updated Direct Download Link

NorbertSandor commented 1 year ago

This version has fixed the issue with 76800 baud rate on Ubuntu :)

hedgecrw commented 1 year ago

Resolved with release v2.10.2