when fly-ready drones get more cameras…

There’s the DJI drones that seemingly own the market at this point. Mostly used to take aerial images and movies. Your average YouTuber will probably have two or more of them.

Turns out that, if you add modern camera technology to these small flying objects and a lot of processing power you can do crazy things like indoor realtime 3D mapping…

Skydio is a vendor to look at when it somes to such interesting mapping applications.

One Soundcard to rule them all

The first sound card I got as an upgrade to a PC without sound back in 90s was the glorious Sound Blaster 16:

There were several different sound card options back in the days and all sounded a bit different.

sound card (also known as an audio card) is an internal expansion card that provides input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces used for professional audio applications.

Wikipedia

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.

more blacker

A month ago I wrote about a very black paint. This month brings me a papepr about an even blacker substance.

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.

Paper: Breakdown of Native Oxide Enables Multifunctional, Free-Form Carbon Nanotube–Metal Hierarchical Architectures

Hertzian Landscapes

I played with SDR – Software Defined Radio – back in 2013. I’ve still got the equipment around.

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.

http://www.hertzianlandscapes.com/

C# PlayStation emulation

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.

Scott Hanselman wrote:

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.

Why the MS-DOS floppy disk cache was valid 2 seconds…

If you’re old enough to have used MS-DOS you know the benefits a read cache introduced back at the time for floppy disks. Without such a cache everything data intensive was magnitudes slower.

Now after all these years more and more stories emerge about how certain thresholds and timeings where set back in the days.

This is such a story:

Mark Zbikowski led the MS-DOS 2.0 project, and he sat down with a stopwatch while Aaron Reynolds and Chris Peters tried to swap floppy disks on an IBM PC as fast as they could.

They couldn’t do it under two seconds.

So the MS-DOS cache validity was set to two seconds. If two disk accesses occurred within two seconds of each other, the second one would assume that the cached values were still good.

Raymond Chen blog

There are more links in the original article – so go there and down that rabbit hole!

AR use-case: Motorcycle Helmet

I do not drive motor cycles. I never found a reason to.

Given that non-experience: I can only assume that something like this helmet would really make a difference for bikers.

With the integrated camera system it will have a rear-view mirror screen in sight all the time and be able to overlay all sorts of information into the field-of-view of the driver. In addition it seems to be capable to augment the audio getting to the driver in various ways.

If you are as interested as I am, despite not having a motorcycle: take a look at the Indiegogo campaign.

DIY Lightboard

Usually when we visited lectures the notes and explanations where given on a chalk board or a projector. With the lecturer looking away from the audience most of the time.

This is where Light Boards come in handy. They allow the lecturer to face his audience and give explanations on a board…

Like so:

I was made aways by Ryan Heffernans tweet on the project he did together with his son. He built one of these light boards! The short clip above shows his son on their board.

My son and I built a lightboard. You write on it like a whiteboard, but you can face your audience and the writing is illuminated. Commercial versions cost around $10k, but we made ours for $400 in parts from Home Depot. Here’s how.

Ryan Heffernan Tweet

Of course there are commercial ready-made ones. But where’s the fun in that?

Multi-Sensor board progress

Still working on these

Still lots of errors and challenges to positioning and casing. It works electrically and in software. Does not yet fit into a case.

It’s supposed to get you these sensors accomodated:

  • barometric pressure
  • temperature
  • humidity
  • PIR motion
  • light intensity
  • bluetooth scan/BLE connectivity
  • Wifi scan / Wifi connectivity

And a RGB LED as output. All powered by USB and an ESP32.

Booting Faster (with Linux).

Booting a computer does not happen extremely often in most use-cases, yet it’s a field that has not seen as much optimization and development as others had.

Find a very interesting presentation on the topic: How to make Linux boot faster here. The presentation was held at the Linux Plumbers Conference 2019.

QuickCharge 3 (QC3) enable your Arduino project

You might have asked yourself how it is that some phones charge up faster than others. Maybe the same phone charges at different speed when you’re using a different cable or power supply. It even might not charge at all.

There is some very complicated trickery in place to make those cables and power supplies do things in combination with the active devices like phones. Many of this is implemented by standards like “Quick Charge”:

Quick Charge is a technology found in QualcommSoCs, used in devices such as mobile phones, for managing power delivered over USB. It offers more power and thus charges batteries in devices faster than standard USB rates allow. Quick Charge 2 onwards technology is primarily used for wall adaptors, but it is also implemented in car chargers and powerbanks (For both input and output power delivery).

Wikipedia: Quick Charge

So in a nutshell: If you are able to speak the quick charge protocol, and with the right cable and power supply, you are able to get anything between 3.6 and 20V out of such a combination by just telling the power supply to do so.

This is great for maker projects in need of more power. There’s lots of things to consider and be cautious about.

“Speaking” the protocol just got easier though. You can take this open source library and “power up your project”:

The above mentioned usage-code will give you 12V output from the power supply. Of course you can also do…:

Be aware that your project needs to be aware of the (higher) voltage. It’s really not something you should just try. But you knew that.

More on Quick Charge also here.

smart arduino fish pond feeder: TurtleFeeder

We’ve got several quite big fish tanks in our house. Mainly used by freshwater turtles.

say Hi! to Wilma.

These turtles need to be fed every once in a while. And while this is not an issue normally it’s an issue if you leave the house for travel for an extended period of time.

Of course there are humans checking on everything in the house regularly but as much as can be automated should and will be automated in our household. So the requirement wa to have the turtle feeding automated.

To achieve this is would be necessary to have a fixed amount of turtle food be dispensed into the tanks on a plan and with some checks in the background (like water quality and such).

It’s been quite a hassle to come up with a plan how the hardware should look like and work. And ultimately i’ve settled on retrofitting an off-the-shelf fish pond feeder to become controllable through MQTT.

The pond feeder I’ve found and used is this one:

It’s not really worth linking to a specific product detail page as this sort of feeder is available under hundreds of different names. It always looks the same and is priced right around the same.

If you want to build this yourself, you want one that looks like the above. I’ve bought 3 of them and they all seem to come out of the same factory somewhere in China.

Anyway. If you got one you can easily open it up and start modifying it.

Hardware

the wheel is turned by a DC motor and the switch is triggered by the wheels fins
I’ve added a connector to the switch and the motor cables for quick connect

The functional principle of the feeder is rather simple:

  1. turn the feeder wheel
  2. take the micro-switch status in account – when it’s pressed down the wheel must be pushing against it
  3. turn it until the micro-switch is not pressed anymore
  4. turn some more until it’s pressed again

Simple. Since the switch-status is not known on power loss / reboot a calibration run is necessary (even with the factory electronics) every time it boots up.

After opening the feeder I’ve cut the two cables going to the motor as well as the micro-switch cables. I’ve added a 4-Pin JST-XH connector to both ends. So I can reconnect it to original state if desired.

These are all the parts needed:

I am using a Wemos D1 Mini and a couple of additional components apart from the prototype board:

A PN2222 NPN transistor, a rectifier diode 1N4007 and a 220 Ohm resistor.

I’ve connected everything according to this schematic I’ve drawn with Fritzing:

I’ve then prototyped away and put everything on the PCB. Of course with very limited solderig skill:

As you can see the JST-XH connector on Motor+Switch can now be connected easily to the PCB with all the parts.

Make sure you check polarity and that you did correctly hook up the motor and switch.

When done correctly the PCB (I’ve used 40mm x 60mm prototype pcb) and all cables will fit into the case. There’s plenty of room and I’ve put it to the side of it. I’ve also directly connected an USB cable to the USB port of the Wemos D1 Mini. As long as you put at least 1A into it it will all work.

Software

Since the Wemos D1 Mini sports an ESP8266 and is well supported by Arduino it was clear to me to use Arduino IDE for the software portion of this project.

Of course everything, from schematics to the sourcecode is available as open source.

To get everything running you need to modify the .ino file in the src folder like so:

Configuration

What you need to configure:

  • the output pins you have chosen – D1+D2 are pre-configured
  • WiFi SSID + PASS
  • MQTT Server (IP(+Username+PW))
  • MQTT Topic prefix

Commands that can be sent through mqtt to the /feed topic.

MQTT topics and control

There are overall two MQTT topics:

  • $prefix/feeder-$chipid/state
    This topic will hold the current state of the feeder. It will show a number starting from 0 up. When the feeder is ready it will be 0. When it’s currently feeding it will be 1 and up – counting down for every successfull turn done. There is an safety cut-off for the motor. If the motor is longer active than configured in the MaximumMotorRuntime variable it will shut-off by itself and set the state to -1.
  • $prefix/feeder-$chipid/feed
    This topic acts as the command topic to start / control the feeding process. If you want to start the process you would send the number of turns you want to happen. So 1 to 5 seems reasonable. The feeder will show the progress in the /state topic. You can update the amount any time to shorten / lengthen the process. On the very first feed request after initial power-up / reboot the feeder will do a calibration run. This is to make sure that all the wheels are in the right position to work flawlessly.

So if you want to make it start feeding 3 times:

mosquitto_pub -t house/stappenbach/feeder/feeder-00F3B839/feed -m 3

And if you want to see the state of the feeder:

mosquitto_sub -v -t house/stappenbach/feeder/feeder-00F3B839/state

All in all there are 3 of these going to be running in our household and the feeding is going to be controlled either by Alexa voice commands or through Node-Red automation.

Homebrew AR: HoloKit

Augmented Reality – AR – is getting some buzz here and there throughout the last 20 years almost. With hardware becoming more powerful and optics+light hardware becoming cheaper and more efficient it’s still all but close to become widely used and available.

Many refer to some one-trick pony feature in location-based games like “Pokemon Go” to being “AR”. But actual useful cases of AR are there but not feasible with current hardware generations.

Nevertheless a team in california has taken our the scissors and keyboards and made HoloKit:

HoloKit features super sharp optics quality and a 76-degree diagonal field of view. Pairing with a smartphone, HoloKit can perform an inside out tracking function, which uses the changing perspective on the outside world to note changes in its own position. HoloKit merges the real and the virtual in a smart way. While you see through the real world, virtual objects are blended into it. Powered by the accurate gyro and camera on smart phones, HoloKit solidly places virtual objects onto your table or floor, as if they were physically there without physical makers. These virtual objects will stay in the same place even if you walk away, just like real physical objects.

HoloKit is different from screen-based AR experience like Tango. You can directly see through the headset and view the real world as is, and in the meantime the virtual objects are projected on top of the real world, as opposed to viewing both the real and the virtual through a smartphone camera.

https://holokit.io/

BlaspBerry v2

Have you ever wanted a full control over your communication tool ? #SnapOnAir #BlaspBerry v2. A true Qwerty computer KB. @Raspberry_Pi
zero W. @Quectel
3G cellular chip. #Lora RFM95 chip. All opensource.

pwav robot on Twitter

There’s a full twitter thread here. More pictures, more information.

And there’s a GitHub repository with some schematics, configurations and so on…

the appropriate case for your hackintosh

It’s been a year since Zenvent posted this:

Created a custom case for my hackintosh, it resembles a minified Power Mac G5. I have uploaded the parts to Thingiverse in case you’d like to make one of your own. 

https://www.zenvent.com/blog/hackintosh/

Hackintosh (a portmanteau of “Hack” and “Macintosh”), is a computer that runs macOS on a device not authorized by Apple, or one that no longer receives official software updates.

https://en.wikipedia.org/wiki/Hackintosh

Functional Threshold Power

I am cycling for fun and for the effect it has on my body and well-being. I do about 30km of cycling every day on average.

After my first stationary trainer broke I bought a new one with the capability to measure wattage and also to apply resistance measured by the watt.

After looking at my average speeds, heart-rates and times on the device I was able to build a quite detailed understanding of the broader picture. What effects my power output and what does not. The effects of nutrition and health to what the body will deliver while being asked the exact same power output curve than the last time.

In a nutshell the numbers tell me that I am usually at a mediocre wattage of 150W constant load doing about 40 km/h average. My reserves usually allow me to go for 1-2 hours without a break doing this.

So far so good. Now I’ve found out from more serious cyclers that there’s something like “Functional Threshold Power“. I do regular have tests at the doctors to check for any heart-rate issues.

Reading about this Functional Threshold Power my curiousity is sparked.

How much could I do? Should I even go for measuring it?

Circuit Board Design in your browser

Once every while when you make things you actually need to make things. Things like PCBs – printed circuit boards to hold and wire your chips.

bold claim

Maybe you want to give EasyEDA a try as it’s in-browser experience is better than anything I had come across so far. Granted I am not doing PCBs regularly but nevertheless – whenever I tried with the programs I’ve got recommended it wasn’t as straight forward as it is with this tool.

code autocomplete with deep learning

When you are writing code the patterns seem to repeat every once in a while. Not only the patterns but also the occasion you are going to apply certain code styles and methods while developing.

To support a developer with this creative work the tedious and repetitious tasks of typing out what is thought can be supported by machine learning.

Chances are your favourite IDE already supports an somehow AI driven code autocomplete feature. And if it does not, read on as there are ways to integrate products like TabNine into any editor you can think of…

Visual Studio IntelliCode is a set of AI-assisted capabilities that improve developer productivity with features like contextual IntelliSense, argument completion, code formatting, and style rule inference.

IntelliCode augments existing developer workflows with machine-learning services that provide an understanding of code and its context. It’s applicable for C#, C++ (in preview), JavaScript/TypeScript (in preview), and XAML code today, and will be updated in the future to support more languages.

Visual Studio IntelliCode

Of course there are some new contenders to the scene, like TabNine:

TL;DR: TabNine is an autocompleter that helps you write code faster. We’re adding a deep learning model which significantly improves suggestion quality. You can see videos below and you can sign up for it here.

TabNine

Deep TabNine requires a lot of computing power: running the model on a laptop would not deliver the low latency that TabNine’s users have come to expect. So we are offering a service that will allow you to use TabNine’s servers for GPU-accelerated autocompletion. It’s called TabNine Cloud, …

TabNine

Emulation

Preserving old software is all about storing it and keeping it running.

With the most important part being the later one. The best way to keep things running is by emulating the old and obsolete hardware as accurate as possible.

In computing, an emulator is hardware or software that enables one computer system (called the host) to behave like another computer system (called the guest). An emulator typically enables the host system to run software or use peripheral devices designed for the guest system. Emulation refers to the ability of a computer program in an electronic device to emulate (or imitate) another program or device.

Wikipedia: Emulator

There are a lot of different types of emulators for all sorts of purposes.

There’s things like bochs which is effectively emulating the hardware of a PC on chip-level and can run virtually anywhere:

Bochs is a highly portable open source IA-32 (x86) PC emulator written in C++, that runs on most popular platforms. It includes emulation of the Intel x86 CPU, common I/O devices, and a custom BIOS. Bochs can be compiled to emulate many different x86 CPUs, from early 386 to the most recent x86-64 Intel and AMD processors which may even not reached the market yet. 

bochs: the Open Source IA-32 Emulation Project

Emulators of game consoles are alike that – they are emulating the whole system hardware and are able to run original and unchanged code by replicating the exact hardware. Sometimes more and sometimes less exactly.

Hardware emulation in itself an extremely interesting field of software engineering. There’s the hard way to emulate everything accurately (and slowly) by doing what the actual old hardware would have done but maybe in software (or even in replicated hardware).

And there is harder way to emulate the software and hardware by applying all sorts of optimization techniques like JIT (just in time) compilation and dynamic recompilation.

In regards of old game console hardware there are even now specialized distributions of lots of hardware/system emulators available for specific and readily available hardware like the RaspberryPi. Some of them recently have gotten some nice updates.

Retropi

supported systems

Recalbox

Beautiful bits – information from old catalogs

There are many connectors out in the world. A lot of them are old but get still used. And once every while you might need an actual great drawing / scheme of such a connector.

There’s a place for all your needs and curiosity. It’s bitsavers.org.

Just take a look at this drawing and cut-away of a coax connector from the 1976 AMP product catalog:

There is lots more, just take a look at bitsavers. Especially the software bits archive of (very) old computers software and sources. Just wow.

electronic fireworks

The firecracker exploded. Apparently after 2 weeks of usage of the Chuwi Hi10 Air the eMMC flash is malfunctioning.

In a totally strange way: Every byte on the eMMC can be read, seemingly. Even Windows 10 boots. But after a while it will hang and blue screen. Apparently because it tries to write to the eMMC and when those writes fail and pile up in the caches at some point the system calls it quits.

Anyhow: It means that no byte that is right now on this eMMC can be deleted / overwritten but only be read.

The great chinese support is really helpful and offered to replace the device free of charge right away. That’s very nice! But I came to the conclusion that I cannot send the device in, because:

It contains a full set of synched private data that I cannot remove by all means because the freaking soldered-on eMMC flash is broken.

The recipient of this broken tablet in china would be able to read all my data and I could not do anything about it.

Only an extremely small fraction of data is on there unencrypted. Only that much I hadn’t yet switched on encryption on during the initial set-up I was still doing on the device. And that little piece of data already is what won’t let me send out the device.

Now, what can we learn from this? We can learn: Never ever ever work with anything, even during set-up, without full encryption.

retrofit an old printer to be available on the network

In 2007 I had become proud owner of a Samsung ML-2010 mono laser printer. It’s done a great job ever since and I can recall changing the toner just once so far.

So you can tell: I am not a heavy printer user. Every so often I gotta print out a sheet of paper to put on a package or to fill out a form. A laser printer is the perfect fit for this pattern as it’s toner is not going-bad or evaporating like ink does in ink-printers.

So I still like the printer and it’s in perfect working condition. I’ve just recently filled up the toner for almost no money. But – but this printer needs to be physically connected to the computer that wants to print.

As the usage patterns have significantly changed in the last 12 years this printer needs to be brought into todays networked world.

Replacing it with a new printer is not an option. All printers I could potentially purchase are both more expensive to purchase and the toner is much more expensive to refill. No-can-do.

If only there was an easy way to get the printer network ready. Well, turns out, there is!

First let’s start introducing an opensource project: CUPS

CUPS (formerly an acronym for Common UNIX Printing System) is a modular printing system for Unix-like computer operating systems which allows a computer to act as a print server. A computer running CUPS is a host that can accept print jobs from client computers, process them, and send them to the appropriate printer.

Wikipedia

A good, cheap and energy-efficient way to run a CUPS host is a Raspberry Pi. I do own several first-generation models that have been replaced by much more powerful ones in the previous years.

So I’ve taken one Raspberry Pi and did the set-up steps: Installing the Raspberry Pi Print Server Software.

And now – what did I get?

I got a networked Samsung Laser Printer. No thrills, no problems at all.

the CUPS web interface
the printer shows up on Linux (Ubuntu here)
on iOS and macOS the printer magically appears
on Windows 10.

a wild Ma.K (Maschinen Krieger) appears

The franchise was started by Kow Yokoyama in the 1980’s. Yokoyama-san was a scratch-build modeller, artist and sculptor. Among his works he built machines of war that would fight in the 29th century, but took their visual cues from early 19th century weaponry and the early NASA space program. All his models were pieced together from numerous kits including armor, aircraft, cars and found objects (like ping pong balls).

Ma.K

Often described as WWII machinery in space, these kits are the perfect blend of sci-fi modelling with AFV weathering and finishing techniques…

There is also a longer article with high-resolution pictures here.

brain simulators

With recent announcements around human brain and brain-machine interface research like Neuralink the topic is seemingly seeing some more investments now.

As this whole topic is special to my heart I am interested in all things brain simulations. Thus here’s my personal “logbook entry” on the re-appearance of this topic:

This leads to one of the arguments for whole-brain simulation: it’ll help us solve the “biological imitation game,” a Turing test-like assay that pits digitally reconstructed brains against real ones. Iterations of the test help select increasingly more accurate models for a given task, which eventually become the most promising ideas for how specific biological networks operate. And because these models are based on mathematical equations, they could become the heart of next-generation AI.

Singularity Hub

There’s also a paper! – Unfortunately I cannot link directly to the paper as it is behind paywalls. Neuralink on the other side was so kind to publish open-access:

visualize baby sleep pattern

A visualization of my son’s sleep pattern from birth to his first birthday. Crochet border surrounding a double knit body. Each row represents a single day. Each stitch represents 6 minutes of time spent awake or asleep

Seung Lee on Twitter

No babies here. But I want such a blanket now.

augmented (reality) book cover

If you ever want to quickly explain what augmented reality could be to a person not knowing yet, you might want to use this (and other) use cases for a visual explanation:

I achieved this by separating the artwork and text into many individual layers, that I placed in receding layers of 3D depth, in a 3D program on the computer. And made sure everything outside the borders of the book is excluded, to give it the ‘portal’ effect.

Augmented Reality Book Cover by Alexander Wand

Tool: Partition Recovery and Undelete – Testdisk

Mass storage hardware breaks all the time. Sometimes it’s hardware that breaks, but sometimes it’s the software that breaks. If it’s the software (or own talent) that made the data go boom, TestDisk is a tool you should know about.

DISCLAIMER: If the data you are trying so recover is actually worth anything you might want to reserve to a professional data recovery service rather than trying to train-on-the-job.

Apart from the availability of pre-compiled packages for most operating systems you can also grab a bootable LiveCD when everything seems gone and lost.

The process itself is rather exciting (if you want the data back) and may require a fresh pair of pants upfront, throughout and after.

Thankfully there’s a great wiki and documentation of how to go about the business of data recovery.

TestDisk is powerful free data recovery software! It was primarily designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software: certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy.

  • TestDisk can
    • Fix partition table, recover deleted partition
    • Recover FAT32 boot sector from its backup
    • Rebuild FAT12/FAT16/FAT32 boot sector
    • Fix FAT tables
    • Rebuild NTFS boot sector
    • Recover NTFS boot sector from its backup
    • Fix MFT using MFT mirror
    • Locate ext2/ext3/ext4 Backup SuperBlock
    • Undelete files from FAT, exFAT, NTFS and ext2 filesystem
    • Copy files from deleted FAT, exFAT, NTFS and ext2/ext3/ext4 partitions.

TestDisk has features for both novices and experts. For those who know little or nothing about data recovery techniques, TestDisk can be used to collect detailed information about a non-booting drive which can then be sent to a tech for further analysis. Those more familiar with such procedures should find TestDisk a handy tool in performing onsite recovery.

And if you give up, think about writing an article of you actually digging deeper: