Since a picture says more than a thousand words, I give you the result first:
my crkbd based keyboard
This keyboard design is made from the ground up as open source and naturally is fully available as a GIT repository containing everything you need to start: PCB schematics, drawing, documentation and firmware source code.
It took me a couple of months to get all the required parts ordered and delivered. Many small envelopes with parts that seemlingly are only produced by a handful of manufacturers. But anyways: After everything had arrived and was checked for completeness my wife took the hardware parts into her hands and started soldering and assembling the keyboard.
And so this project naturally is split up between my wife and me in the most natural (to us) way: My wife did all the hardware parts – whilst I did the software and interfacing portion. (Admittedly there only was to be figured out how to get the firmware compiled and altered to my specific needs)
After putting the hardware together it was time to get the firmware sorted as well. This keyboard design is based upon the open source QMK (Quantum Mechanical Keyboard) firmware.
Conveniently QMK comes with it’s own build tools – so you will be up and running in no time. Since I had purchased Arduino ProMicro controllers I was good with the most basic setup you can imagine. As the base requirements for the toolchain where minimal I went with the machine that I had in front of me – a Raspberry Pi 4 with the standard Raspberry Pi OS.
These where the steps to get going:
get Python 3 and the qmk tool installed – I’ve chosen not to use the tool setup procedure but instead go with a separate clone of the QMK firmware repository.
python3 -m pip install --user qmk
clone the QMK firmware repository and get the QMK tool running (in the /bin folder of the firmware repository – it’s actually just a python script)
git clone https://github.com/qmk/qmk_firmware.git
cd qmk_firmware
git submodule sync --recursive
git submodule update --init --recursive --progress
make crkbd:default
create your own keymap to work with. You gotta use the crkbd firmware options as a default for this keyboard. The command below will generate a subfolder with the name of your keymap in the keyboards/crkbd/keymaps folder with the default settings of the crkbd keyboard firmware.
qmk new-keymap -kb crkbd
build your first firmware by running the command below (note: btk-corne is the name of my keymap)
now you can flash the firmware to both ProMicro controllers. The most straight forward way for me was using avrdude on the commandline. In my case the device is added as /dev/ttyACM0 and the compiled firmware named crkbd_rev1_legacy_btk-corne.hex.
When you got all this information you need to plug in the ProMicro and trigger a reset by bridging Ground and the Reset Pin. If you added, like we did, a button for reset you can use this. After hitting reset the ProMicro bootloader will enter the state where it’s possible to be flashed. Reset it and THEN run the avrdude commandline.
(alternatively) you can also use QMK Toolbox to flash the firmware. Also works.
So now you know how to get the firmware compiled and running (if not, look here further). But most probably you are not happy with some aspects of your keymap or firmware.
By now you might ask yourself: Hey, I’ve got two ProMicros on one keyboard. Both are flashed with the same firmware. Into which of the two do I plug in the USB cable that then is plugged into the computer?
The answer is: by default QMK assumes that you are plugging into the left half of the keyboard making the left half the master. If you prefer to use the right half you can change this behaviour in the config.h file in the firmware:
You have to plug in both of them anyway at times when you want to flash a new firmware to them as you adjust and make changes to your keymap.
Thankfully QMK comes with loads of options and even a very useful configurator tool. I used this tool to adjust the keymap to my requirements. The process there is straightforward again. Open up the configurator and select the correct keyboard type. In my case that is crkbd/legacy. The basic difference between legacy and common is a different communication protocol between the two halves. This really only is important when features are used that require some sort of sync between the two haves – like some RGB LED effects. Since I did not add any LEDs to the build I go with legacy for now. Maybe I need some features later that require me to go with common.
The configurator allows you to set up the whole keymap and upload/download it as a .json file.
That .json file can easily be converted into the C code that you need to alter in the actual keymap.c file. Assuming that the .json file you got is named btk-corne.json the full commandline is:
qmk json2c btk-corne.json
Then simply take this output and replace the stuff in the keymap.c with it:
Now you compile and flash again. And if all went right you’ve got the new keymap and firmware on your keyboard and it’ll work just like that :)
Diesmal gehen wir der Frage nach, wie viel Speicherplatz ein 5 Meter PNG File benötigt, das Daniel für seinen DIY Arcarde Automaten gebaut hat, wundern uns über LED-Leuchten an, die wie echter Himmel aussehen sollen und freuen uns über den “Digitalen Alltag als Experiment”.
Wir haben uns wieder zusammengefunden – diesmal mit unserem Gast Philipp von nerdbude.com – und haben über Tastaturen, Github Arctic Vault, OCRmyPDF und einen selbstgebauten Arcade Automat gesprochen.
Wie schon bei der letzten Folge 23 haben wir zusätzlich zur Tonspure eine Videospur aufgezeichnet – allerdings nicht als “Talking-Heads” Episode sondern während wir über die Themen sprechen versuchen wir die Themen mit zusätzlichem Inhalt zu unterfüttern – Links und Bilder eben.
When you are dealing with IoT protocols, especially at hobby-level, you probably came across the MQTT protocol and the challenge to have all those different devices that are supposed to be connected actually get connected – preferably using the MQTT protocol.
Recently this little project came to my attention:
OpenMQTTGateway project goal is to concentrate in one gateway different technologies, decreasing by the way the number of proprietary gateways needed, and hiding the different technologies singularity behind a simple & wide spread communication protocol: MQTT.
OpenMQTTGateway support very mature technologies like basic 433mhz/315mhz protocols & infrared (IR) so as to make your old dumb devices “smart” and avoid you to throw then away. These devices have also the advantages of having a lower cost compared to Zwave or more sophisticated protocols. OMG support also up to date technologies like Bluetooth Low Energy (BLE) or LORA.
The authorisation of the rightholder shall not be required where reproduction of the code and translation of its form within the meaning of points (a) and (b) of Article 4(1) are indispensable to obtain the information necessary to achieve the interoperability of an independently created computer program with other programs, provided that the following conditions are met:
(a) those acts are performed by the licensee or by another person having a right to use a copy of a program, or on their behalf by a person authorised to do so;
(b) the information necessary to achieve interoperability has not previously been readily available to the persons referred to in point (a); and
(c) those acts are confined to the parts of the original program which are necessary in order to achieve interoperability.
The provisions of paragraph 1 shall not permit the information obtained through its application:
(a) to be used for goals other than to achieve the interoperability of the independently created computer program;
(b) to be given to others, except when necessary for the interoperability of the independently created computer program; or
(c) to be used for the development, production or marketing of a computer program substantially similar in its expression, or for any other act which infringes copyright.
In accordance with the provisions of the Berne Convention for the protection of Literary and Artistic Works, the provisions of this Article may not be interpreted in such a way as to allow its application to be used in a manner which unreasonably prejudices the rightholder’s legitimate interests or conflicts with a normal exploitation of the computer program.
Curtesy of Sam Zeloof I came around the fact that I’ve got a good part of a FSTM in a cupboard here.
Apparently my choice of purchasing the HD-DVD drive for the Xbox 360 will ultimately pay off!! As we all know Bluray won that format war back in the days.
But now it seems that this below would be useable for something:
Over the life of nuclear fuel, inhomogeneous structures develop, negatively impacting thermal properties. New fuels are under development, but require more accurate knowledge of how the properties change to model performance and determine safe operational conditions.
Measurement systems capable of small–scale, pointwise thermal property measurements and low cost are necessary to measure these properties and integrate into hot cells where electronics are likely to fail during fuel investigation. This project develops a cheaper, smaller, and easily replaceable Fluorescent Scanning Thermal Microscope (FSTM) using the blue laser and focusing circuitry from an Xbox HD-DVD player.
Since I am back at developing the Head-Up-Display app I was writing about in February (yeah, mornings got darker again!) I want to leave this nice looking Odometer Javascript library here:
Odometer is a Javascript and CSS library for smoothly transitioning numbers. See the demo page for some examples.
Odometer’s animations are handled entirely in CSS using transforms making them extremely performant, with automatic fallback on older browsers.
Now that I am thinking about it – there is a practical use-case that I will look into in the coming months for sure for it. And just to mention this use case here: With SDR I could create a more versatile 443/886 Mhz receiver.
Anyhow. SDR hardware allows you to access a whole spectrum of radiosignals at once. And a common way to visualize the spectrum is to draw the amplitudes in a line add each new measurement as a new line – color/brightness coded.
What you get is some sort of waterfall diagram that looks like this:
Hertzian Landscapes (2019) is a live visualization of the radio spectrum. Unlike visible light, waves in the radio spectrum cannot be perceived by us directly yet this space is teeming with human activity. Hertzian Landscapes employs a digital receiver to scan large swaths of radio spectrum in near real-time and visualizes thousands of signals into a panoramic electromagnetic landscape. Users can zoom in to specific frequencies by positioning themselves in front of the panorama as if controlling a radio tuner with their body, giving them a sense of walking through the spectrum. From radio broadcasts to weather satellites and from medical implants to aeronautical navigation, the radio spectrum is divided into hundreds of designated slices each tied to a specific application. Based on a localized frequency database that describes these slices, signals are annotated to provide information about their theoretical type and application.
After looking into the NES emulation written entirely in C# I came across a similar approach using C# to emulate a full and much more complex PlayStation 1.
I then stumbled on this very early version of a PSX Emulator in C#.
Now, if you were to theoretically have a Playtation SCPH1001.BIN BIOS and then physically owned a Playstation (as I do) and then created a BIN file from your physical copy of Crash Bandicoot, you could happily run it as you can see in the screenshot below.
