The Canadian Hydrographic Service (CHS) at Fisheries and Oceans is changing its way of doing things and now offers access to its data a REST application programming interface. It is therefore necessary to modify the Python scripts which obtain the hours and heights of high and low tides [...more (in French)]
After printing a few objects created by others with my new 3D printer, I wanted to try my hand at creating a practical 3D object with OpenSCAD. This post shows how I designed a tablet stand made of two three-dimensional A's with curly hooks at the ends of the legs that wrap around the bottom edge of the tablet [...more]
A fractious look at the GNU gettext translation system as implemented in Free Pascal / Lazarus... Finally getting around to partly documenting the use of the reference field when dealing with PO files in the poutils utilities. [...more]
Not Much Going On
It may seem as if not much is happening on this site lately. But appearances can be deceiving and a number of projects are in various stages of development. Recently, I have uploaded three projects to my GitHub account:
- domoticiz_button: a very simple home automation controller. Based on an ESP8266 dev board such as the D1 Mini or nodemMCU, a small 0.96" OLED display and a combination rotary switch and push button, just about every IoT device in the house can be controlled through the Domoticz home automation server. MQTT is used to communicate with the server.
- lazmqttc: a basic MQTT client written in Free Pascal/Lazarus using the Eclipse mosquitto library. It was fun to program in Free Pascal again.
- poutils: which are command line utilities to modify Free Pascal/Lazarus .po translation files.
This is a trend that will continue: posts with more or less detailed explanations will continue to be available here, but accompanying code will be made available through GitHub if I think that distribution model is best.
There is conflict between the
python-is-python2 packages that may need to be resolved when installing TortoiseHg and Virtual Box in Mint 20.1
[...more (in French)]
Yet again, the scanner in the Brother DCP-7040 multifunction printer does not work out of the box in Ubuntu 20.04 and Mint 20.1. In addition to fixing the changes to the directories that contain third-party scanner drivers, it is now necessary to install an old library to manage USB connections [...more]
In September 2020, I made a snap decision to get a ANYCUBIC Mega Zero 3D printer almost immediately after seeing YouTube videos about it. The printer was available in Canada at a surprisingly low price. The version I bought is being supplanted by the Mega Zero 2.0 but currently Americans can obtain the original Mega Zero at a very low price of $119 US + shipping charges. Not knowing how long this offer would last, I hurriedly wrote down my first impressions of the printer, in the hope that they could help other beginners who, like me, just want to try 3D printing before committing to a large expense [...more]
As a temporary measure, I have installed OctoPrint and MJPG-Streamer on a Raspberry Pi 3. Since I intend to replace the Pi with a different single-board computer, I did not install the SD image OctoPi but instead proceeded with a manual installation of the needed packages just as I will have to do it with the other sbc in a short while [...more]
Installing a WireGuard virtual private network server on openmediavault running on an x86-64 system was faster and simpler than on the Raspberry Pi. The user and server configuration script by Adrian Mihalko worked just as well with just a little tweak for the network interface name. [...more]
Setting up Wi-Fi with a static address on this very small single-board computer running the Debian or Ubuntu OS images provided by
A second version of RaspberryPi OS has been available since December 2019. Preliminary tests have shown that, much like its predecessor, this updated version of Raspbian from the Raspberry Pi Foundation brings nothing much that is new insofar as installing and using the virtual private network software WireGuard is concerned. As far as I can tell there is one less step required in the installation process [...more]
The first version of the "minimalist" Internet Radio did not generate much enthusiasm at home, so here is a new improved version [...more]
Just set up a satisfying Internet Radio which is a minimalist implementation of the GitHub project, ESP32-Radio, in less time than it took to write this post. Many thanks to Ed Smallenburg (Edzelf) for his repository [...more]
A section with links to more information on the web about the XIAO was added to the original post [...more]
With a USB-C port and with two I/O pins providing USART Tx and Rx connectivity, the XAIO can fill in as a USB to serial converter in a pinch [...more]
The post contains a general approach to creating and using
GFXfont type fonts containing up to 224 characters arbitrarily chosen from plane 0 of the Unicode character set. This proposal respects the
Adafruit-GFX library's prime directive which is to maintain compatibility with existing Arduino sketches, since no changes are made to
Adafruite-GFX. The post is similar to the one published on October 23 and replaces the October 8 post which was withdrawn
[...more (in French)]
The default licence for my code on this site has been changed to the BSD Zero Clause License created by Rob Landley. I have also finally got around to being more explicit about the copyright for the posts found here [...more]
A few days ago, someone sent a message to my Facebook account. Unfortunately, I somehow managed to delete the message without reading it nor can I remember the coordinates of the sender. I am sorry that I cannot reply and hope that the sender will accept my apologies.
Please do not try to reach me through Facebook/Messanger which is reserved for family and friends. Instead use the e-mail link at the bottom of each page and you will get a reply.
This is a much needed update of the original October 2017 post on how
to set up rsyslog on Raspberry Pi OS as a centralized
syslog server and how to
enable remote error loggin in Tasmota
By default, proportional fonts that can be used with the Adafruit GFX Library and other libraries that are compatible with GFX fonts are limited to the 95 printable 7-bit ASCII characters (code points 32 (0x20) to 126 (0x7E). This is my attempt at supporting 8 bit character sets which is throwback to the pre UCS, pre Unicode code page concept. A modified
fontconvert utility, called
fontconvert8 can extract any subset of glyphs from a TTF font although I have included only two examples: ISO 8859-1 (Latin 1) and ISO 8859-15 (Latin 9). Then I have written two
utf8tocp functions to simplify displaying UTF-8 encoded strings using these fonts with displays. This is not a universal solution, anyone wanting to use a different code page than the two provided will have to modify
fontconvert8 source and the
French Diacritical Letters with Adafruit GFX Fonts
Removed, soon to be replaced with something better... hopefully. Once again I have run into problems associated with French diacritical letters. The fonts supplied in the library that I use with a TFT display only contain ASCII characters from 32 to 126. However, the library is compatible with Adafruit_GFX type proportional fonts and it is relatively easy to add additional glyphes taken from the Latin-1 block in Unicode that corresponds to the ISO 8859-1 code page
Installation and configuration of Ubuntu 20.04 Server on an older computer with a lesson learned about network configuration in Ubuntu [...more]
Self inflicted wound: I had not expected that changing the domain name servers would break time synchronization on the backup server [...more]
Belated Spring Cleaning
After delaying for quite some time, I have begun the long and boring job of cleaning up this site. This involves a slightly fresher and more compact start to each page as seen here. The home automation and programming indexes were removed mostly to make my life easier but also because I was feeling increasingly cramped with that choice.
There are now only two search engines on tap for a local search. I chose DuckDuckGo and StartPage because of their privacy claims. This choice is not an endorsement, as I have no way of verifying if a site tracks searches and uses, shares or sells the data. Searches limited to this web site with the usual search engines can be done from the archives page.
Converting the whole site will take quite some time. So far, the posts published in the last 12 months and a few older ones have the new look. Hopefully, nothing is broken but please send me an e-mail (link at the bottom) if there is something wrong.
The WireGuard package is now included in the Debian and Raspbian
testing repositories. The latter is very good news, because the
While Raspberry Pi OS, the newest version of the "official" operating system for the Raspberry Pi, has changed name, it remains based on the 4.19 Linux kernel just as Raspbian Buster had been. Nevertheless, I tried to improve my post on the installation and configuration of a WireGuard virtual network server, because it is one of the most consulted pages on this site. There is an addendum showing how to install WireGuard on all Raspberry Pi models using a "beta" Raspbian WireGuard package [...more]
PlatformIO now supports the Seeeduino XIAO. Some prefer PlatformIO to the Arduino IDE. New users of PlatformIO or those that are curious about that programming environment may want to consult this short post on how to upload a very simple program to the XIAO in that environment [...more]
While Raspberry Pi OS and Raspbian Buster are both based on Debian 10 and the 4.19 Linux kernel, there are differences that made my Febrary post about a ubiquitous DS3231 real-time clock with an AT24C32 EEPROM module out of date . I found it easier to leave the old post in place, and copy and paste most of it in this new article, only changing what needed to be fixed in the new OS. That way, it will not be necessary to refer to the old article unless one is still using Raspbian [...more]
Once again, I will try to set up reasonable backup strategies. In this post, I discuss an important part of that endeavour, backing up the home automation server data files [...more]
This post is another of those that document my never ending need to learn something about micro-controllers. This time I am investigating the Serial Peripheral Interface (SPI) on the Raspberry Pi. I examine both the hardware and the Python
spidev module and even attempt to update a "well-known" document about the later which was available about five years ago
There are some good explanations on how to add a serial communication interface on SAM D21 based boards. However all those that I have found are for boards with many more I/O pins than the XIAO so that they are not that pertinent for this tiny board. In this post, I explain just what the problem is and how it is nevertheless possible to add a supplementary SPI, I²C or USART port on the XIAO as long as another type of communication interface is forgone [...more]
A very knowledgeable reader of the first version of the Overview of the SAMD21 Arm Cortex-M0+ Based Seeeduino XIAO kindly provided instructions to manually install the XIAO board definition in the PlatformIO development environment. Because all the hard work was already done for me, it was a simple two-step procedure [...more]
Using the XIAO in master mode to control and I²C slave device was already discussed in the first look at the Seeeduino XIAO. The topic of I²C communication with the XIAO is again the topic but this time the emphasis is on data exchange with a Raspberry Pi. To the latter, the XIAO will appear to be an I²C analogue light sensor [...more]
For a few reasons, I decided to rewrite in large part the instructions on how to self-host a WireGuard
virtual private network on a Raspberry Pi. For one thing, the original post was rushed because at it was difficult to
get the correct repository keys. At the time, I was in the process of writing a long winded yet superficial explanation of VPN. Reading my old post
when answering a query from someone, it became clear that there was a supposition that readers had read that non-existent dissertation.
Clearly, pieces of the puzzle were missing. Another problem was that the old post was getting... old. More bits were expended on
Stretch than on
Buster which is now on its third edition
While reviewing my ESP8266 router watchdog code, it struck me that using a blocking (or synchronous) ping library to check the status of the Internet connection was not the proper approach. In this post, I present an example project that monitors if the Internet can be reached using the AsyncPing library by akaJes [...more]
This post contains my first impressions of the Seeeduino XIAO from Seeed Studio. Because I don't really have much experience with micro-controllers except for a bit of work with the ESP8266 and the occasional experiment with Arduino boards, this overview will be at a rather superficial level. Nevertheless, it describes some 15 Arduino sketches showing different capabilities of this new development board. Hopefully, this will be of interest to others starting out with this impressive little board [...more]
Seeed Studio has come out with a new board called the Wio Lite RISC-V with ESP8266. The unusually shaped board is based on the 32-bit RISC-V GD32VF103CBT6 micro-controller by GigaDevice. In addition there is a Wio core based on an ESP8266 which should provide Wi-Fi connectivity. The development software is not yet completed at least for the Arduino platform, but I did manage blink the on board LED with the PlatformIO development environment on a Linux desktop [...more]