The only meter in our house that I was not yet able to read out automatically was the water meter.
With the help of a great open source project by the name of AI-on-the-edge and an ESP32-Camera Module it is quite simple to regularly take a picture of the meter, convert it into a digital read-out and send it away through MQTT.
The process is quite simple and straightforward.
Flash the ready made Firmware image to the module
Configure the WiFi using a SD card
Put the module directly over the meter
Connect to it and setup the reference points and the meter recognition marks
As you can see above all the recognition is done on the ESP32 module with its 4MByte of RAM.
With the data sent through MQTT it’s easy to draw nice graphs:
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)
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
git submodule sync --recursive
git submodule update --init --recursive --progress
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 :)
I like playing arcade games. I’ve had an “arcade” in my home town and I used to go there after school quite frequently. It was a small place – maybe 5 machines and some pinball machines.
In february this year it occured to be that with the power of the Raspberry Pi and a distribution called RetroPie I could build something that would bring back the games and allow me to play/try those games I never could because my arcade was so small back in the days.
With their basic plans I started drawing in Inkscape and told my father about the plan. He was immediately in – as the plan now was to not build one but two bartop arcade machines. He would take the task of carrying out the wood works and I would do the rest – procurements, electronics, wiring, design and “painting”.
While I took the Holbrook Tech schematics as a base it quickly came apparent that I had to build/measure around the one fixed big thing in the middle: the screen.
I wanted something decently sized that the RaspberryPi would be able to push out to and that would require no maintenance/further actions when installed.
To find something that fits I had my requirements fixed:
between 24″ – 32″
colour shift free wide viewing angle
takes audio over HDMI and is able to push it out through headphone jack
I eventually settled for a BenQ GW2780 27″ monitor with all boxes ticked for a reasonable price.
After the monitor arrived I carried it to my fathers house and we started to cut the bezel as a first try.
After some testing with plywood we went for MDF as it was proposed by others on the internet as well. This made the cutting so much easier.
We went with standard 2cm MDF sheets and my father cut them to size with the measurements derived from the monitor bezel centerpiece.
Big thanks to my father for cutting so much wood so diligently! The next days he sent me pictures of what he’d made:
The side panels got a cut around for the black T-Molding to be added later.
electronics and wiring
After about 2 weeks my father had built the first arcade out of sheets of MDF and I had taken delivery of the remaining pieces of hardware I had ordered after making a long list.
It contains 2 standard 4/8-way switchable arcade joysticks, 10 buttons, all microswitches required and the Ultimarc I-PAC-2 joystick encoder.
So when I got the first arcade from my father I started to put in the electonics immediately.
The sound was a bit more complicated. I wanted a volume control knob on the outside but also did not want to disassemble any audio amplifier.
I went with the simplest solution: A 500k Ohm dual potentiometer soldered into the headphone extension cable going to the amplifier. The potentiometer then got put into a pot and a whole made it stick out so that a knob could be attached.
The RaspberryPi set-up then only lacked cooling. The plan was to put a 120mm case fan to pull in air from the bottom and went it out another 120mm case hole at the upper back. Additionally the RaspberryPi would get it’s own small 30mm fan on top of it’s heatsink case.
I attached both fans directly to the RaspberryPi – so I saved myself another power supply.
Now I had to make it all work together. As I wanted to use RetroPie in the newest 4.6 release I’ve set that up and hooked it all up.
On first start-up EmulationStation asked me to configure the inputs. It had detected 2 gamepads as I had put the IPAC-2 into gamepad mode before. You can do this with a simple mode-switch key-combination that you need to hold for 10 seconds to make it switch.
The configuration of the buttons of the two players went without any issue. First I had set-up the player 1 input. Then I re-ran the input configuration again for player 2 inputs.
The controls where straight forward. I wanted mainly 4-way games but with enough buttons to switch to some beat-em-ups at will.
So I configured a simple layout into Retroarch with some additional hotkeys added:
I tossed around several design ideas I had. Obviously derived from those games I wanted to play and looked forward to.
There was some Metal Slug or some Cave shooter related designs I thought of. But then my wife had the best ideas of them all: Bubble Bobble!
So I went and looked for inspiration on Bubble Bobble and found some but none that sticked.
There was one a good inspiration. And I went to design based upon this one – just with a more intense purple color scheme.
I used Inkscape to pull in bitmap graphics from Bubble Bobble and to vectorize them one by one, eventually ending up with a lot of layers of nice scalable vector graphics.
With all design set I went and sliced it up and found a company that would print my design on vinyl.
With the final arcade-wood accessible top me I could take actual measurements and add to each element 4cm of margin. This way putting it on would hopefully be easier (it was!).
Originally I wanted to have it printed on a 4m by 1,2m sheet of vinyl. It all would have fit there.
But I had to find out that Inkscape was not capable of exporting pixel data at this size and a pixel-density of 600dpi. It just was too large for it to output.
So I had to eventually cut all down into 5 pieces of 1,2m by 80cm each.
After about 7 days all arrived printed on vinyl at my house. I immediately laid everything out and tried if it would fit. It did!
Now everything had to go onto the wood. I did a test run before ordering to check if it would stick securely to the wood. It did stick very nicely. So putting it on was some intense fiddling but it eventually worked out really really great.
Now it was time for some acrylic. I wanted to get a good bezel and covering of the monitor as well as the handrest and the front buttons.
Cutting acrylic myself was out of questions – so I went with a local company that would laser-cut acrylic for me to my specification.
I’ve sent them the schematics and measurements and the panels for reference and 4 days later the acrylic arrived. We could then put the last bits together for completion!
I am really happy how this turned out – especially since with everything that required actual work with hands I am a hopeless case. With this somehow everything worked out.
I still employ the idea of a vertical shoot-em-up centered version… but maybe some day.
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.
For all other cases I am using the HDDGuru tool on Windows.
HDD Raw Copy Tool is a utility for low-level, sector-by-sector hard disk duplication and image creation.
Supported interfaces: S-ATA (SATA), IDE (E-IDE), SCSI, SAS, USB, FIREWIRE.
Big drives (LBA-48) are supported.
Supported HDD/SSD Manufacturers: Intel, OCZ, Samsung, Kingston, Maxtor, Hitachi, Seagate, Samsung, Toshiba, Fujitsu, IBM, Quantum, Western Digital, and almost any other not listed here.
The program also supports low-level duplication of FLASH cards (SD/MMC, MemoryStick, CompactFlash, SmartMedia, XD) using a card-reader.
HDD Raw Copy tool makes an exact duplicate of a SATA, IDE, SAS, SCSI or SSD hard disk drive. Will also work with any USB and FIREWIRE external drive enclosures as well as SD, MMC, MemoryStick and CompactFlash media.
It’s 3.8 kg and delivers 25.5 kg of force. Impressive! And it’s in stores (in Japan).
The “Every Muscle Suit” has a lot going for it. Weighing just 3.8 kilograms, the pneumatic artificial muscle suit is powerful enough to generate up to 25.5 kilogram-force and effectively relieves pressure on users’ backs when performing activities like heavy lifting.
Best of all, its streamlined design conceals an advanced air pressure system that doesn’t require electricity or batteries.
Please read this first paragraph and let it settle:
At the core of the BrainScaleS wafer-scale hardware system (see Figure 90) is an uncut wafer built from mixed-signal ASICs , named High Input Count Analog Neural Network chips (HICANNs), which provide a highly configurable substrate that physically emulates adaptively spiking neurons and dynamic synapses (Schemmel et al. (2010), Schemmel et al. (2008)).
I’ve highlighted in bold the portion that I want you to think about once more. We are not talking about chips, dies or cut-up wafers.
We are talking about real-size, huge, fully developed wafers filled with logic. For the sole purpose of brain scale neural network research and development…
The Neuromorphic Computing Platform allows neuroscientists and engineers to perform experiments with configurable neuromorphic computing systems. The platform provides two complementary, large-scale neuromorphic systems built in custom hardware at locations in Heidelberg, Germany (the “BrainScaleS” system, also known as the “physical model” or PM system) and Manchester, United Kingdom (the “SpiNNaker” system, also known as the “many core” or MC system). Both systems enable energy-efficient, large-scale neuronal network simulations with simplified spiking neuron models. The BrainScaleS system is based on physical (analogue) emulations of neuron models and offers highly accelerated operation (104 x real time). The SpiNNaker system is based on a digital many-core architecture and provides real-time operation.
Current generations of RaspberryPi single board computers (from 3 up) already got WiFi on-board. Which is great and can be used, in combination with the internal ethernet or even additional network interfaces (USB) to create a nice wired/wireless router. This is what this RaspAP project is about:
This project was inspired by a blog post by SirLagz about using a web page rather than ssh to configure wifi and hostapd settings on the Raspberry Pi. I began by prettifying the UI by wrapping it in SB Admin 2, a Bootstrap based admin theme. Since then, the project has evolved to include greater control over many aspects of a networked RPi, better security, authentication, a Quick Installer, support for themes and more. RaspAP has been featured on sites such as Instructables, Adafruit, Raspberry Pi Weekly and Awesome Raspberry Pi and implemented in countless projects.
This really is going to be very useful while on travels. I plan to replace my GL-INET router, which shows signs of age.
Shorthand is an abbreviated symbolic writing method that increases speed and brevity of writing as compared to longhand, a more common method of writing a language. The process of writing in shorthand is called stenography, from the Greekstenos (narrow) and graphein (to write). It has also been called brachygraphy, from Greek brachys (short) and tachygraphy, from Greek tachys (swift, speedy), depending on whether compression or speed of writing is the goal.
I’ve upgraded just before the Japan travelling to the current iPhone generation. I was expecting some improved battery life but I did not dare to think I would get THIS.
I’ve taken the last 3 generations of iPhones on trips to Japan and they all went through the same exercises and quite comparable day schedules.
The amount of navigation, screen-time, taking pictures and just browsing the web / translating led to all 3 previous generations to be out-of-juice just around half-day.
Not this generation. Apparently something has changed. Not really in terms of screen time – screen on-time got better, but not as great as the overall usage time of the device with screen off.
In regards of how much power and runtime I am getting out of the device without having to reach for a batter pack or power supply is astonishing. I am using my Apple Watch for navigation clues so I am not really reaching out for the phone for that. But that means the phone is constantly used otherwise to make pictures, payments, translations….
I am comfortably leaving all battery packs and chargers at home when all the time before I was charging the phones at lunchtime for the first time. I usually had to charge 2 times a day to get through.
With this generations iPhone 11 Pro I am getting through the whole day and reach the hotel just before getting down to 20%.
I am still using it all throughout the day. But this is such a relief that I am confidently getting through a full day of fun. Thumbs up Apple!
RTL-SDR is a very cheap ~$25 USB dongle that can be used as a computer based radio scanner for receiving live radio signals in your area (no internet required). Depending on the particular model it could receive frequencies from 500 kHz up to 1.75 GHz. Most software for the RTL-SDR is also community developed, and provided free of charge.
The origins of RTL-SDR stem from mass produced DVB-T TV tuner dongles that were based on the RTL2832U chipset. With the combined efforts of Antti Palosaari, Eric Fry and Osmocom (in particular Steve Markgraf) it was found that the raw I/Q data on the RTL2832U chipset could be accessed directly, which allowed the DVB-T TV tuner to be converted into a wideband software defined radio via a custom software driver developed by Steve Markgraf. If you’ve ever enjoyed the RTL-SDR project please consider donating to Osmocom via Open Collective as they are the ones who developed the drivers and brought RTL-SDR to life.
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.
Can you display VGA and play audio on a Cortex-M4 in pure Rust? The short answer is yes, yes you can! Minus the hand-unrolled assembler loop for fixing the phase error in the RGB output. But we don’t talk about that in polite company.
The Atari Joystick interface works, but two Joysticks would be more fun
The PS/2 Keyboard via the Atmega works, but the pinout was mirrored so you have to put the connector under the PCB :/
The RTC works
VGA Output works
The MIDI Out seems to work when looped to MIDI In, as does the MIDI Though.
The MIDI In seems to receive data when connected to my electronic drum kit
The Audio output seems to work quite nicely
The SD card works, but the power supply can’t handle hot-insertion of the SD card and it makes the TM4C reboot. More capacitors / some current limiting probably required.
I can load games and programs from the SD card into the 24 KiB of free Application RAM. You can interact with these games via the PS/2 Keyboard and Joystick. I can play simple games (like Snake) and play three channels of 8-bit wavetable audio simultaneously. I’ve even got a 6502 Emulator running a copy of 6502 Enhanced BASIC, if you want to go old school!
As you might know I am regularly looking into indoor-location systems and opportunities to optimize my own system (based on Bluetooth…)
Now I cam across a concept by a german company called Localino. They’ve built their own hard- and software.
Localino has its own “satellites”, also called “anchors”. The mobile receivers are called “tags” and can locate their position based on the available anchors inside a building. Anchors and tags precisely measure signal propagation delays in the order of sub-nanoseconds, resulting in centimeter-accurate location. Any person or object wearing a tag can be located.
With the synthesizers and audio processing each series and make produced a distinctive sound. Some of us want to bring these sounds back. But keeping the (old) hardware running is an increasingly difficult task.
For example: The interface used by the above mentioned Sound Blaster 16 card is the ISA bus interface. This interface was introduced in 1981 and replaced in 1993. If you want to hear how such a sound card sounds today you would have to run hardware from this time period.
But some people are working towards getting at least some authentic sound back.
In this talk, Alan Hightower takes a look at the complexities, challenges, and even current progress at integrating all of the above cores into one FPGA based ISA sound card.
This is what the concept would bring if done:
Oh that would be soooooo nice to have all these vintage sound interfaces available and to be able to actually use them for audio output.
The synergistically incorporated CNT–metal hierarchical architectures offer record-high broadband optical absorption with excellent electrical and structural properties as well as industrial-scale producibility.