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by swampdog
Wed Apr 08, 2020 8:33 am
Forum: Raspberry Pi Desktop for PC and Mac
Topic: JY-R2T (rs232 adapter)
Replies: 7
Views: 450

Re: JY-R2T (rs232 adapter)

I managed to read what the chips are: Sipex sp3232een 634lt7320 (v1.4) https://www.maxlinear.com/ds/sp3222e_sp3232e.pdf Max3232 ese+1240 (v1.3) http://www.ti.com/lit/ds/symlink/max3232.pdf ..or at least supposed to be (I dont know what exe+1240 means). On the face of it they appear similar enough. I...
by swampdog
Wed Apr 08, 2020 5:21 am
Forum: Raspberry Pi Desktop for PC and Mac
Topic: JY-R2T (rs232 adapter)
Replies: 7
Views: 450

Re: JY-R2T (rs232 adapter)

I believe I've got that part correct though it does no harm to verify. Atm two of the zero's are rpiZW. The remainder is a plain rpiZ with a wifi dongle. host type os rs232 --------------------------------- pi13 rpiZW stretch v1.4 pi22 rpiZ buster v1.4 pi21 rpiZW stetch v1.3 foo@pi13:~ $ tail -3 /bo...
by swampdog
Tue Apr 07, 2020 10:35 pm
Forum: Raspberry Pi Desktop for PC and Mac
Topic: JY-R2T (rs232 adapter)
Replies: 7
Views: 450

Re: JY-R2T (rs232 adapter)

Ah. I seem to have neglected to mention these adapters are connected to raspberry pi's running raspbian! This is the only link I can find https://www.amazon.co.uk/Serial-Adapter-Module-JY-R2T-Joystick/dp/B077K5XF5M noting I likely didn't get them from there. I'm powering them from the 3.3v gpio pin ...
by swampdog
Tue Apr 07, 2020 3:45 pm
Forum: Networking and servers
Topic: Passwordless SSH From Windows 10
Replies: 3
Views: 693

Re: Passwordless SSH From Windows 10

I heard win10 can do ssh natively now? I don't know the details. I always install cygwin and its openssh client, which, once configured, works just like linux. Just run "ssh-user-config" on the cygwin side where you see "ssh-keygen" in linux instructions. Don't bother with the cygwin ssh server init...
by swampdog
Tue Apr 07, 2020 3:07 pm
Forum: Raspberry Pi Desktop for PC and Mac
Topic: JY-R2T (rs232 adapter)
Replies: 7
Views: 450

JY-R2T (rs232 adapter)

Has anyone used the 1.3 version? I bought a few some months back. Two are v1.4 and work fine (attached to PC's running centos 7). The rest are v1.3 - you'll see the grub boot screen and everything appears fine(*) until the login prompt: then there's just random junk inserted. [ 28.591633] br0: port ...
by swampdog
Thu Apr 02, 2020 9:10 am
Forum: C/C++
Topic: Library linkage issues while developing a C++/MySQL application
Replies: 2
Views: 586

Re: Library linkage issues while developing a C++/MySQL application

I forgot to mention statically linking mysql is not easy. foo@sdu /wrk/TT $ gcc -o c c.cpp `sd-qt mysql_config --cflags` -Wl,-Bstatic `sd-qt mysql_config --variable=pkglibdir`/libmysqlclient.a -Wl,-Bdynamic -lpthread -ldl -lgnutls -lz ..is what I just figured out it would be for my "slung on the sid...
by swampdog
Thu Apr 02, 2020 8:25 am
Forum: C/C++
Topic: Library linkage issues while developing a C++/MySQL application
Replies: 2
Views: 586

Re: Library linkage issues while developing a C++/MySQL application

I've not built a mysql app for years but I don't see mention of 'mysql_config'. Ignore 'sd-qt' below: it's for a self compiled mariadb "slung on the side" and I'll muck something up if I try edit it out. Just pretend 'sd-qt' doesn't exist. foo@sdu ~/usr/src $ sd-qt mysql_config --cflags -I/usr/local...
by swampdog
Thu Apr 02, 2020 7:38 am
Forum: Beginners
Topic: Mariadb Run as PI versus Run as Root
Replies: 35
Views: 1371

Re: Mariadb Run as PI versus Run as Root

ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/run/mysqld/mysqld./sock’ (2) Is that period/slash in the path a typo? Fwiw, I just did 'apt-get install mariadb-server' (Y) on a fresh buster install and 'sudo mysql' logged right in. foo@pi20:~ $ sudo ls -l /var/run/mysql...
by swampdog
Thu Apr 02, 2020 6:43 am
Forum: General discussion
Topic: Locking LXTerm and the sudo command
Replies: 12
Views: 416

Re: Locking LXTerm and the sudo command

A handy tip for these kind of "might lock myself out of root" situations (eg: sudo,ssh) is to have two terminals onto the target. In one terminal gain root login, then in the second, do the work and test. That way if you make a mistake you've still got the first terminal logged in to undo the mistake.
by swampdog
Wed Apr 01, 2020 6:01 am
Forum: Raspberry Pi OS
Topic: Buster CIFS fstab problems
Replies: 3
Views: 675

Re: Buster CIFS fstab problems

I was thinking of one of those macs built into a tv! This is from a centos 6 server but may help with tweaking some options.. [admin@sdvmc64smb ~]$ cat /etc/samba/smb.conf [global] server string = Samba Server Version %v log level = 1 auth:3 # log level = 4 WORKGROUP = TURNIP smb ports = 139 domain ...
by swampdog
Thu Mar 26, 2020 8:25 pm
Forum: Raspberry Pi OS
Topic: Buster CIFS fstab problems
Replies: 3
Views: 675

Re: Buster CIFS fstab problems

iMac is old. So is my samba server. Try downgrading the version. From the command line this (buster) pi can log in.. foo@pi18:~ $ sudo mount -t cifs -o credentials=/home/foo/.smbcred,gid=1000,uid=1000,vers=1.0 //smb/Administrator /mnt/tmp ..and has full access. foo@pi18:~ $ cat .smbcred username=Adm...
by swampdog
Thu Mar 26, 2020 7:49 pm
Forum: C/C++
Topic: Troubleshooting linked libraries
Replies: 4
Views: 387

Re: Troubleshooting linked libraries

My throwaway pi is not working atm so for a guess..

Code: Select all

$ldd /usr/lib/arm-linux-gnueabihf/libcec.so.4
..and 'objdump -CT' kind of approach will reveal undefined symbols in there, will be pulling the other libs in.

Caveat. I don't use Buildroot.
by swampdog
Thu Mar 26, 2020 7:21 pm
Forum: Advanced users
Topic: Raspberry Pi 4b, 2 Seagate 4TB USB External Drives and lvm2
Replies: 11
Views: 960

Re: Raspberry Pi 4b, 2 Seagate 4TB USB External Drives and lvm2

Stick with lvm. It's tried and tested tech. I've been using it on my rpi4's for a few months now. Getting reliable hardware/peripherals was a pain (mostly solved by self powered stuff as you've found). One of the rpi4's has three identical caddies attached to it, each with a 3Tb disk. They're just e...
by swampdog
Tue Mar 24, 2020 2:26 am
Forum: C/C++
Topic: Qt 5.14
Replies: 7
Views: 1070

Re: Qt 5.14

I used "examples/multimedia/audiodevices/player/player.pro TEMPLATE = app TARGET = player QT += network \ xml \ multimedia \ multimediawidgets \ widgets HEADERS = \ player.h \ playercontrols.h \ playlistmodel.h \ videowidget.h \ histogramwidget.h SOURCES = main.cpp \ player.cpp \ playercontrols.cpp ...
by swampdog
Thu Mar 19, 2020 1:47 pm
Forum: C/C++
Topic: Qt 5.14
Replies: 7
Views: 1070

Re: Qt 5.14

So, I did compile (after some time) and run, but this message does lead me to believe that I still need something newer than 5.11.3 to run successfully: defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.audiodecode" If you can narrow it down to a few compilable lin...
by swampdog
Thu Mar 19, 2020 1:34 pm
Forum: C/C++
Topic: Qt 5.14
Replies: 7
Views: 1070

Re: Qt 5.14

That's good because once you start down the road of building QT from source it can get rather large. I wanted an identical 5.12.5 for both raspian and my PC with the rule that major prerequisites had to be built from source on both if either needed it. So with gcc/cmake/mysql/clang/qt/qtcreator (wit...
by swampdog
Wed Mar 11, 2020 10:44 pm
Forum: Beginners
Topic: Bash subscripted variable output from for do done loop
Replies: 13
Views: 695

Re: Bash subscripted variable output from for do done loop

If I'm understanding you correctly then methinks you might want to "man at" (sudo apt-get install at). Set up your cronjob normally but use 'at' to trigger it on sunset. Start with a wrapper script which defines the environment. 'at', like 'cron' uses a restricted environment so let's make it a bit ...
by swampdog
Fri Mar 06, 2020 6:10 pm
Forum: C/C++
Topic: Needing help learning programming in c++
Replies: 8
Views: 848

Re: Needing help learning programming in c++

A quick look at http://www.umsl.edu/~antognolij/gaddis.html Ch03 (C03-1.ppt) section 26 (typecasting) reveals it is a proper C++ course so (for example you could code this).. #include <iostream> #include <cstdlib> int main(void) {int x1 (7), y1 (5), x2 (10), y2 (10); double m; m = static_cast<double...
by swampdog
Fri Feb 21, 2020 4:56 pm
Forum: Advanced users
Topic: mSATA USB interface for Pi 4 – TRIM for SSD?
Replies: 2
Views: 940

Re: mSATA USB interface for Pi 4 – TRIM for SSD?

I turned it on for one of my LVM partitions on a large SSD where there's a lot of activity - constantly building and deleting source code and have not noticed any problems so far. It is also enabled in /etc/lvm/lvm.conf. As to whether it is doing anything - I dunno!
by swampdog
Fri Feb 21, 2020 11:15 am
Forum: General discussion
Topic: Pi Zero W VT100 Terminal
Replies: 5
Views: 624

Re: Pi Zero W VT100 Terminal

The pi I use to connect to headless PC's with serial ports uses minicom is set thus: Welcome to minicom 2.7 OPTIONS: I18n +---------[Comm Parameters]----------+ Compiled on Apr 22 201| | Port /dev/serial0 | Current: 115200 8N1 | | Speed Parity Data | Press CTRL-A Z for hel| A: <next> L: None S: 5 | ...
by swampdog
Thu Feb 20, 2020 10:57 am
Forum: Raspberry Pi OS
Topic: Issue when using NoMachine
Replies: 2
Views: 263

Re: Issue when using NoMachine

Yeah, I think that's because without a monitor plugged in the rpi4 hasn't started a gui so nomachine creates a virtual desktop. You'll likely also discover when you open a gui terminal your keyboard mapping is wrong (defaults to american). The latter problem doesn't bother me enough to sort it out b...
by swampdog
Thu Feb 20, 2020 10:22 am
Forum: Beginners
Topic: SSH - Copy keys to another computer or create new keys?
Replies: 8
Views: 387

Re: SSH - Copy keys to another computer or create new keys?

It depends how far ahead you want to plan! +----------+ +--------+ +--------+ | Internet |--|Firewall|--|Intranet| +----------+ +--------+ +--------+ | v ssh is sole allowed inbound port Intranet: +--------+ |DNS/DHCP| <- someuser@pi07 +--------+ | | v | this public key on | all internal boxes | +--...
by swampdog
Thu Feb 20, 2020 8:44 am
Forum: General discussion
Topic: How did I mount my thumb drive?
Replies: 14
Views: 629

Re: How did I mount my thumb drive?

Nothing there. Open a terminal.. $ sudo tail -f /var/log/syslog Now plug in the thumb drive. Some text should occur. Post that. CTRL-C to stop that "tail -f" when done. I find it handy to hit CR a couple of times when I start a "tail -f" so it's easier to separate the current stuff from the new mess...
by swampdog
Thu Feb 20, 2020 8:17 am
Forum: Advanced users
Topic: USB SSD Fails on Large File on RPi4
Replies: 18
Views: 2012

Re: USB SSD Fails on Large File on RPi4

The (unpowered) hub I used was named.. "Lenovo 4-Port USB 3.0 Hub, Portable Data Hub Compatible for USB A Devices, 5Gbps Transfer Speed" ..which is plugged into powered caddies. In case the url wakes up again: https://www.amazon.co.uk/gp/product/B07D5TTJLG/ (broken at time of posting). I don't have ...
by swampdog
Wed Feb 19, 2020 5:16 pm
Forum: Beginners
Topic: Keeping files in sync across multiple, LAN attached Pi’s
Replies: 5
Views: 290

Re: Keeping files in sync across multiple, LAN attached Pi’s

Is there a reason not to use rsync?

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