Day: November 18, 2020

C64 Runs On STM32F429 Discovery

November 18, 2020 by 23 Comments

There have been various reincarnations of the Commodore C64 over the years, and [Dave Van Wagner] has created one that can run on an STM32F429ZI Discovery development board. These dev boards have been around quite a few years and feature a 2.4 inch color TFT LCD in addition to the typical I/O circuitry, and are a pretty good value — [Dave] says they currently sell for under $30 through distribution.

The project began earlier this year when [Dave] set out to write a command line program in C# that emulated C64 Basic. He had written a 6502 emulator many years earlier, but had not tested it. [Dave] went on a programming binge in March and got it up and running over a very long weekend. He subsequently decided to add support for VIC-20, TED, and PET as well.

Even though [Dave] says C# is a beautiful language, he subsequently ported the program into C (an ugly language?) in order to run on the Discovery board, swapping the command line terminal interface for real LCD video and a USB keyboard. There’s also an Arduino version (terminal interface only). It runs about 15% slower than a real C64, and there are some limitations still like no SID. But overall, this is a great project and a low-cost way to emulate a C64 in an embedded format. If you want to explore further, here is the Mbed project for the STM32F429, and you can find the Arduino and C# versions on his GitHub page. You may remember [Dave] from the C128 video hack we wrote about last year.

Turning GitHub Into A URL Shortening Service

November 18, 2020 by 11 Comments

URL shortening services like TinyURL or Bitly have long become an essential part of the modern web, and are popular enough that even Google killed off their own already. Creating your own shortener is also a fun exercise, and in its core doesn’t require much more than a nifty domain name, some form of database to map the URLs, and a bit of web technology to glue it all together. [Nelsontky] figured you don’t even have to build most of it yourself, but you could just (ab)use GitHub for it.

Using GitHub Pages to host the URL shortening website itself, [nelsontky] actually repurposes GitHub’s issue tracking system to map the shortened identifier to the original URL. Each redirection is simply a new issue, with the issue number serving as the shortening identifier, and the issue’s title text storing the original URL. To map the request, a bit of JavaScript extracts the issue number from the request, looks it up via GitHub API, and if a valid one was found (and API rate limits weren’t exceeded), redirects the caller accordingly. What’s especially clever about this is that GitHub Pages usually just serves static files stored in a repository, so the entire redirection logic is actually placed in the 404 error handling page, allowing requests to any arbitrary paths.

While this may not be as neat as placing your entire website content straight into the URL itself, it could be nicely combined with this rotary phone to simply dial the issue number and access your bookmarks — perfect in case you always wanted your own website phone book. And if you don’t like the thought of interacting with the GitHub UI every time you want to add a new URL, give the command line tools a try.

Giving Recalled Fitness Trackers A Second Chance

November 18, 2020 by 6 Comments

When it was released back in 2012, the Basis B1 fitness tracker was in many ways ahead of its time. In fact, the early smartwatch was so impressive that Intel quickly snapped up the company and made it the cornerstone of their wearable division. Unfortunately a flaw in their next watch, the Basis Peak, ended up literally burning some wearers. Intel was forced to recall the whole product line, and a year later dissolved their entire wearable division.

Given their rocky history, it’s probably no surprise that these gadgets can be had quite cheaply on the second hand market. But can you do anything with them? That’s what [Ben Jabituya] recently decided to find out, and the results of his experiments certainly look very promising. So far he hasn’t found a way to activate a brand-new Basis watch, but assuming you can get your hands on one that was actively being used when Intel pulled the plug, his hacks can be used to get it back up and running.

Examining the downloaded sensor logs.

The Basis Android application has long since been removed from the Play Store, but [Ben] said it wasn’t too hard to find an old version floating around on the web. After decompiling the application he discovered the developers included a backdoor that lets you configure advanced options that would normally be hidden.

How do you access it? As a reminder of the era in which the product was developed, you simply need to log into the application using Jersey and Shore as the username and password, respectively.

Between the developer options and API information he gleaned from the decompiled code, [Ben] was able to create a faux Basis authentication server and point the application to it. That let him get past the login screen, after which he was able to sync with the watch and download its stored data. Between examinations with a hex editor and some open source code that was already available online, he was able to write a Python script for parsing the data which he’s been kind enough to share with the world.

We’re very pleased to see an open source solution that not only gets these “bricked” smartwatches back online, but allows the user to keep all of the generated data under their own control. If you’d like to do something similar with a device that doesn’t have a history of releasing the Magic Smoke, the development of an open source firmware for more modern fitness trackers might be of interest.

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Actuator Opens The Door To Drier Dishes

November 18, 2020 by 41 Comments

Dishwashers are great at washing dishes and even rinsing them, most of the time. Where they tend to fail is in the drying part. Somehow these things dry hot enough to warp stoneware dishes, but not so well that things are actually dry when you open the door. Blame it on the lack of air movement.

Ideally, the dishwasher cycle is started soon after dinner time so it can be finished and opened up before it’s time for bed. But if you do that, then you miss all the dishes from late-night snacking and the occasional wine glass. Wait until bedtime to start it, and it has to sit several hours with moisture inside. Obviously, the answer is to listen for the victory beeps at the end of the cycle, and use a slow but forceful actuator to push the door open.

[Ivan Stepaniuk] is listening for the dishwasher’s frequencies with a microphone, amplifying them with a trusty LM386, and using an STM32 blue pill to crunch the audio. [Ivan] has plans to incorporate an ESP8266 board for IoT, presumably to get a notification when the door has been opened successfully. Check out the demo after the break.

Yes, dishwashers are great until they aren’t, and some little part breaks. But why pay for a new detergent compartment cover when you can just print one?

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Easy Device Configuration For Your Pi Projects

November 18, 2020 by 14 Comments

We’re all familiar with a typical configuration sequence for a new mass-market IoT device. Turn it on for the first time and it exposes a temporary Wi-Fi network, connect to that network and open a Web page for device configuration. Wouldn’t it be useful to be able to incorporate that functionality into your own projects without having to write it yourself! Happily now thanks to [Peter Walsh] you can, with his AppDaemon project for the Raspberry Pi.

At its heart is  a set of Perl scripts that run whatever your software is, then monitor a GPIO. A button press toggling the GPIO stops the application and fires up the access point and web server. Handily the code can all be found in a GitHub repository, and there is a run-through of the features in a video that we’ve placed below the break. It’s not something that will appeal to everybody, but for anyone who has to pass their work onto people who can’t dive into a config file and break out the editor, it should be a particularly useful addition to the armoury.

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Larry Berg And The Purple Open Passion Project

November 18, 2020 by 31 Comments

It all started with an 88-ton Arburg RP300 injection molding machine in the basement, and a bit of inattention. Larry Berg wanted a couple custom plastic plugs for his Garmin GPS, so he milled out a mold and ran a few. But he got distracted, and came back an hour later to find that his machine had made 400. Instead of throwing them away, he mailed them away for free, but then he found that people started throwing money at him to make more. People all over the world.

This is how the Purple Open Project turned into an global network of GPS geeks, selling molded alternatives to the oddball Garmin plugs for pledges to pay an unspecified amount, and ended up producing over 350,000 plugs over 16 years before he passed away in 2012. This is the story of a hacker’s hacker, who wanted to be able to connect his GPS to his computer and use it the way he wanted, and accidentally created an international business.

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3D Printed Electric Motor Wants To Take Flight

November 18, 2020 by 49 Comments

Airplanes and spacecraft have a big problem. The more engine or fuel you have, the more engine and fuel you need. That’s why aircraft use techniques to have lightweight structural members and do everything they can to minimize weight. A lighter craft can go further and carry more payload or supercargo. Electric motors are very attractive for aircraft, but they suffer from having less efficiency per kilogram than competing technologies. H3X thinks they can change that with their HPDM-250 integrated motor and inverter.

Although the 15 kg motor is still in testing, the claimed specifications are impressive: a peak power of 250 kW for 30 seconds and continuous torque of 95 Nm and 200 kW sustained. The company claims 96.7% efficiency. The claims are for the motor running at 20,000 RPM, so you’d need to add the weight of a gearbox for practical applications, but the company says this adds a mere 3 kg to the overall weight.

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