Linux

Fix whitespace

Written by  on January 24, 2019

Sometimes there is too much whitespace and tabs in my last commit.
In former times I used a VisualStudio-plugin, but this is not helpful there. So I wrote a small script (see on my github) which:
β€’ replaces all tabs with four spaces
β€’ removes all trailing whitespace
β€’ converts line-endings to CRLF

I invoke it on the list of all changes files in my last commit in the git-repo with:

(first part gives you a list of changed files and then feeds it to the script for execution)

keep the catcam up to date

Written by  on July 10, 2018

Logging in to the raspberry(ies) to update them on a regular basis takes time and effort. Both are currently dear.
Also: while the catcam is taking pictures, you can’t update the rpi-binaries.

So I made this nice script, which first suspends the catcam-operation while renaming the script from the cronjob, then does all updates, reverts the renaming and then reboots the MCU.

Make it executeable via ‘sudo chmod +X updateCatcam.sh’ and also add it as cronjob (once a day).

rsync: get all files from the camera’s sd-card .. without interruption

Written by  on July 6, 2018

Of course, you need the same source- and target-directory πŸ˜‰
Using this, because Nautilus (or how that horrible explorer is called) is prone to auto-unmounting the card while transfer due to heavy load ..

backup often, backup early: Duplicati

Written by  on May 1, 2018

I wanted an open source-solution which allows to backup locally and remote certain directories (or whole PC). I found some month ago duplicati and used it for good at work, where it currently backups the content of the whole SSD-partitions to some interal hard disk (not the most secure backup, I know. But given to the constraints still better than no backup at all.)
At home the content of the two home-directories (Linux) is transferred to a shared folder on the Synology-NAS.
duplicati on wikipedia // code under GNU LGPL

I can just repeat: working without a backup is the best path to failure.
In my history as “computer technician” I have ruined several drives and especially when you just want to do a default, simple operation (*cough* move a partion on a hard drive *cough*), everything fails and there is no way to revert back to the original state. Never again πŸ™‚

Cullendula

Written by  on April 3, 2018

Small program to pick out the best shots of the vast amount of taken pictures per session (excursion). The name itself is a wordplay of the plant Calendula and the activity “to cull” (slang for sorting the photos).

url for the repository: https://github.com/marcelpetrick/Cullendula/
development time for fully usable version 0.1: one day
used technologies: C++ and Qt – my favorite ones <3

netdata for monitoring several (headless) Raspberries

Written by  on March 13, 2018

I had netdata already recommended once two years ago, but .. it was quite helpful to track down the issue with the camera on the catcam-raspberry. Yes, of course I could login via SSH or VNC and then manually check if it is still running, or just call “catcam:19999” in the browser.

Install on Raspbian Jessy via:

Catcam upgraded!

Written by  on March 13, 2018


Terminator is watching you!

Finally! The old catcam-setup of a RPi 3 with a NoIR v2.1-camera was working for almost one and ahalf years without any issues. I’ve had improved the PiCamGifForTumblr-script several times, also changed location – never any issues. More than 40.000 GIF were uploaded.
But then I decided to buy a new, fancy case in black (of course) which should add some camera-support. And then two weeks afterwards it stopped working. Sporadically frozen. Sometimes 10 min after start, sometimes during the night. I checked the casing, if all power connectors were tightly fit, I installed netdata on it, I did longterm temperature-measurements (never over 54 Β°C even with closed case), I ran with minimal setup or with cam attached.
Then it became clearer: the camera was working for singleshot-mode, but for the 30 pictures every ten minutes, it broke. So, it was time to order a new camera, 1080p (5 MPixel) were enough, but for four more Euro I could get two IR-illuminators … so, why not? The focal distance of the objective is adjustable, it looks like it works (long time-test needed). But I am happy. And we can watch cats (and family) in darkness :3

tracking bugs in complex systems ..

Written by  on March 6, 2018

Some weeks ago I’ve replaced the case of the ‘catcam’. A Raspberry Pi 3 which was running for 1.5 years without interruption with the nice script & python-upload triggered by a cronjob. And now the device freezes. Still running, but neither accessible via SSH nor VNC (of course, if SSH is not working ..).
I left the case open; removed the camera; upgraded kernel and Raspbian: nothing helped.
My last guess is that the camera stopped working. But to be sure I want to let the RPi3 long-time with temperature-logging. So … we need a simple program:

executed like this, because else the output is buffered up to 4 or 8 kByte:

and the content of the textfile is something like:

backup your Raspberry Pi-sd card

Written by  on February 28, 2018

Newer versions (8.24+) of coreutils dd have also a progress-option, but not the one bundled with the current distribution ..
add param: “status=progress”

banner generator: figlet (online)

Written by  on February 11, 2018

Ok, most of the times your classes and functions shall be commented.
So, let us decorate a bit: your wish shall be my command πŸ˜‰
I had just remembered the good old toolkit to generate banners!

url: http://patorjk.com/software/taag/