Re: USB-serial adapter suggestions needed
- Reply: Mark Millard : "Re: USB-serial adapter suggestions needed"
- In reply to: Bernd Walter : "Re: USB-serial adapter suggestions needed"
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Date: Wed, 27 Dec 2023 02:09:31 UTC
On Tue, Dec 26, 2023 at 02:06:59AM +0100, Bernd Walter wrote: > On Tue, Dec 26, 2023 at 12:02:50AM +0000, Marcin Cieslak wrote: > > On Sun, 24 Dec 2023, bob prohaska wrote: > > > > > I do see what looks like noise on the serial lines, but only after a spontaneous > > > disconnect and only with FTDI adapters. When the serial connections are working > > > nothing resembling noise is seen. > > > > How does that noise look like? > It appears to be non-ascii. I can't get it to copy and paste in a way that's recognizable to me, but here's a sample anyway, taken from bob@pelorus:~ % uname -a FreeBSD pelorus 14.0-RELEASE-p4 FreeBSD 14.0-RELEASE-p4 #0 releng/14.0-n265400-4edf3b80733e: Wed Dec 27 20:21:26 PST 2023 bob@pelorus:/usr/obj/usr/src/arm64.aarch64/sys/GENERIC arm64: ........ # tip ucom connected FreeBSD/arm64 (www.zefox.org) (ttyu1) login: �������� Password: Login incorrect ........... The backslash letter pairs are clearly different, but they're displayed on a RasPiOS lxterminal window as a white oval with a dark question mark in the middle. Sometimes printable characters show up, but it doesn't look like my memory of a baudrate mismatch on a serial modem. Maybe that's just an artifact of modern character sets. > If the tip process was stopped by the ssh disconnect then the uart will fall > back to its default bps rate. > Some USB uarts still buffer received data in the chip itself, with the wrong > bps rate. > > > Did you try to run respective sshd daemons in the debug mode to log disconnects > > and possible their reason? I did, and didn't see anything recognizable as an error. It seemed the session just stopped. No errors, nothing. Whether it's ssh that stopped or tip that stopped seems to be the primary mystery. What I see is ssh stopping, but that may be more symptom than cause. Ssh sessions not involving tip/cu don't stop, at least not as often. Thanks for writing, bob prohaska > > > > -- > B.Walter <bernd@bwct.de> https://www.bwct.de > Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.