Shepard’s Pi

“Shepard’s Pi” is one continous song that lasts for 999,999,999 hours, or about 114 years.

Canton Becker’s music generating algorithm composed this music using the first one billion digits of pi (p). Each digit (3.1415…) determines four seconds of music, supplying the “turn signals” used to determine every musical expression.

Because the numbers in pi never repeat, each of the million hours of “Shepard’s Pi” music are in fact unique. By fast forwarding to some distant moment in the song, you are virtually guaranteed to find yourself listening to something that nobody else – including Canton himself – has ever heard before.

Shepard’s Pi

turn an Xbox 360 HD-DVD drive into an Fluorescent Scanning Thermal Microscope (FSTM)

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.

The Design, Construction, and Thermal Diffusivity Measurements of the Fluorescent Scanning Thermal Microscope (FSTM)

As mentioned, Sam Zeloof shows off the actual chip in more detail:

Xbox 360 HD DVD player photodiode chip reverse engineering, includes 49 bits of antifuse trimming from the factory

Streamsheets

Streamsheets is, similar to NodeRed, a tool to step in between MQTT data coming in and something being done with it. Just other than NodeRed it is not based on flows but on a spreadsheet that executes in it’s entirety everytime a step is made.

Streamsheets are a new spreadsheet technology specifically designed for real-time data stream processing and the opportunities of digitization and the Industrial IoT.

Streamsheets

SwiftUI on the Web

SwiftUI is the new cool kid on the block when it comes to iOS/iPadOS/macOS application development.

As Apple announced SwiftUI early 2019 it’s naturally only focussing on making all the declarative UI goodness available for the Apple operating systems. No non-apple platforms in focus. Naturally.

But there are ways. With the declarative way of creating user interfaces one apparently can simply start to re-implement the UI controls and have them render as HTML / Javascript…

The SwiftWebUI project is aiming to do so:

Unlike some other efforts this doesn’t just render SwiftUI Views as HTML. It also sets up a connection between the browser and the code hosted in the Swift server, allowing for interaction – buttons, pickers, steppers, lists, navigation, you get it all!

In other words: SwiftWebUI is an implementation of (many but not all parts of) the SwiftUI API for the browser.

To repeat the Disclaimer: This is a toy project! Do not use for production. Use it to learn more about SwiftUI and its inner workings.

SwiftWebUI

Making a RISC-V operating system using Rust

As RISC-V progressively challenges the existing ARM processor ecosystem it’s interesting to see more and more software projects popping up that aim that RISC-V architecture.

Here’s one project that aims to develop (and explain along the way) how to create an operating system from scratch. On top of the RISC-V specifics this tutorial also aims to teach how this all can be done in a programming language called Rust.

Keep in mind that all of this is done on a baremetal system. No other software is running.

RISC-V (“risk five”) and the Rust programming language both start with an R, so naturally they fit together. In this blog, we will write an operating system targeting the RISC-V architecture in Rust (mostly). If you have a sane development environment for RISC-V, you can skip the setup parts right to bootloading. Otherwise, it’ll be fairly difficult to get started.

This tutorial will progressively build an operating system from start to something that you can show your friends or parents — if they’re significantly young enough. Since I’m rather new at this I decided to make it a “feature” that each blog post will mature as time goes on. More details will be added and some will be clarified. I look forward to hearing from you!

The Adventures of OS

a 1980s style computer built today for fun

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.

Monotron project page

What currently is in place:

  • 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!

Localino – Indoor Location

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.

Localino website

There’s also a hack-a-day article on the system which states that all hard- and software would be open source. So far I did not find any source code though…

As far as I could dig into this so far it’s based upon decawave DW1000 hardware and an older base-library of this is available as source code here.

There are some other mentions which are back from 2017 when there seemingly was a big open source portion. Some python code is mentioned but nothing available right away today sadly.

REST-API testing: Reqres

I am back again and developing some smaller APIs for my own use.

As I am learning a new programming language and framework (SwiftUI) and for my little learning project I need to also implement a server backend. Implementing a RESTful service is quite straight-forward but for testing and UI prototyping I actually want to do some testing before really setting up the server side.

To easily test RESTful calls without actually implementing anything I found that Reqres is a quite useful tool to have in the toolbelt:

Apart from some pre-set-up API endpoints with dummy data (like users, …) it also features a request mirror service.

With that you can simply throw a JSON document into the general direction of Reqres and it will put a timestamp on it and return it right away.

Like so:

Writing Network Drivers in C#

Somebody had to do it. Maximilian Stadlmeier did:

User space network drivers on Linux are often used in production environments to improve the performance of network-heavy applications. However, their inner workings are not clear to most
programmers who use them. ixy aims to change this by providing a small educational user space network driver, which is gives a good overview of how these drivers work, using only 1000 lines of C code.
While the language C is a good common denominator, which many developers are familiar with, its syntax is often much more dicult to read than that of more modern languages and makes the driver seem more complex than it actually is.

For this thesis I created a C# version of ixy, named ixy.cs, which utilizes the more modern syntax and additional safety of the C# programming language in order to make user space network driver development even more accessible. The viability of C# for driver programming will be analyzed and its advantages and disadvantages will be discussed.

The actual implementation (with other programming languages as well) can be found here.

Apparently it’s not as slow as you might think:

Hack-The-Planet Podcast: Episode 10

Shownotes

Odometer for the HUD

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.

odometer

Musashikosugi Curry Fest

If you do not know japanese curry yet you are missing out big time.

Unfortunately due to typhoon 19 the Musashikosugi Curry Expo had been cancelled along the overall Kosugi Festival 2019.

But the curry stamp rally did start earlier than the typhoon hit the city and carries on still until end of october.

It works like this:

You go to each restaurant. You eat a meal. You get a stamp.

The more stamps you collect the higher valued the prices. More meal coupons even electronics!

But anyway. It’s all about japanese and indian curry. And for that

As you too might want to tick all 28 restaurants of your bucket list take this map I made of all 28:

As you can see – on the iPhone Google Maps app you even get a nice progress bar of those you already visited. I’ve been to parco curry already – so that counted.

Understand Maladay

Boomtime 5 Aftermath: The Apostle Malaclypse the Elder’s Holyday. A wandering Wiseman of Ancient Mediterrania (“Med-Terra” or middle earth), who followed a 5-pointed Star through the alleys of Rome, Damascus, Baghdad, Jerusalem, Mecca and Cairo, bearing a sign that seemed to read “DOOM”. (This is a misunderstanding. The sign actually read “DUMB”.)

Bulletin Board Systems in the wild

While recording a podcast episode we briefly touched on the topic of bulletin board systems and how we both had operated our own FidoNet BBS in the 90s.

To create a bigger reflux of thoughts:

Synchronet Bulletin Board System Software is a free software package that can turn your personal computer into your own custom online service supporting multiple simultaneous users with hierarchical message and file areas, multi-user chat, and the ever-popular BBS door games.

Everything there to set-up a BBS. Maybe I really need to get out a backup of my old BBS and bring it back online?!

Hack-The-Planet Podcast: Episode 009

TIL: iPhone Visual Voicemal is IMAP

Today I learned that the Apple iPhone re-purposes the IMAP protocol to implement the voice mail feature.

By sniffing the network traffic it was possible to examine the IMAP protocol revealing username and the corresponding hashed password (which allows to repeat a successful login) and of course all voicemail files. We want to highlight, that all the voicemail files have been transferred unencrypted.

Assessment of Visual Voicemail from 2012

replacing MyFitnessPal

Well, it’s about time to do something about MyFitnessPal. In our family we’re using their service by the daily. But just for logging. No reports, no further features used.

But still, we were using it for quite a time now:

almost 5 years logged every-single-day.

The service has started to roll out ads for some time now in their apps. There are only iOS / Android apps available. And a mediocre website.

Just recently they started to announce that their free service will restrict how many years back are going to be stored. From those 5 years we will loose 3.

In addition the whole integration has never gotten to a point where I would have decided to upgrade to the paid premium version. No functionality ever got added. No interfacing with scales, no optimizations for UI/UX, …

But they now reduce the functionalities and service and want me to cough up a bit of money:

I am not generally against subscriptions. But I am not getting 9,99 Euro of value out of the service. A shared google sheet would almost achieve parity. And the price itself is just not value based. For 2 Euro I probably would not feel the urge to move on. For 9,99 (times 2 for 2 accounts) make me move.

So I’ve sat down with my wife and we scribbled up some things we want to have in a replacement. The content and feature-set is agreed. Now I’ll throw up a prototype app.

It’ll be integrated with the MQTT scales. And with the flow we came up with we hopefully will reduce the interactions dramatically over MyFitnessPal. And it’ll never stop saving history. And I’ll learn something new.

ASCII browser games

A lot is going on in browsers these days. They are becoming increasingly powerful and resource-demanding.

So it just feels natural to combine high resource usage infrastructure with low resource using graphics to get the worst of both worlds.

Not quite, but you get the idea.

There’s a guy on the internet (haha) who dedicates time to write ASCII / character based graphics engines and games with it.

Meet MrGumix:

Of course, what’s that games and graphics?

Exhibit #1:

And the more advanced Exhibit #2:

Rifftrax revisited

I gave Rifftrax a swing in 2006 when they started their project. Now it’s time for a revisit.

Rifftrax was created by the same people that created and made the series “Mystery Science Theater 3000” so successfull.

Think of this: You go to the movies. Bad movies mostly. And there are 3 of your friends next to you and constantly commenting the movie – in a funny way.

Credit: Comedy Central

Since MST3k had ended a long long time ago the people behind it have started to do the same with current movies. And this they called “Rifftrax”:

Mike Nelson, Bill Corbett and Kevin Murphy, the former stars of Mystery Science Theater 3000, create commentaries for B-movie oddities and Hollywood blockbusters. It’s like watching a movie with your funniest friends!

Their catalog has grown from 0 in 2006 to over 222 full length feature movies and much much more shorts.

If you have never experienced their art: Give them a try. You’ll probably laugh a lot!

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.