This ESP32 Bluetooth Page Turner Can’t Get Any Easier

May 27, 2021 by 8 Comments

Commercial Bluetooth pedals, designed to allow musicians to flip pages of sheet music on a tablet, have the sort of inflated price tag you’d expect for a niche electronic device. Rather than forking as much as $100 USD over for the privilege of hands-free page flipping, [Joonas Pihlajamaa] decided to build his own extremely low cost version using an ESP32 and a cheap foot pedal switch.

In terms of hardware, it does’t get much easier than this. All [Joonas] had to do was hook the pedal up to one of the ESP32’s digital pins, and plug the microcontroller into a USB power bank. From there, it became a software project. With the ESP32-BLE-Keyboard library, it only took a few lines of code to send RIGHT_ARROW or LEFT_ARROW depending on whether the pedal was quickly tapped or held down for a bit; allowing him to navigate back and forth through the pages with just one button.

[Joonas] mentions that the ESP32 development board he’s using is too large to fit inside the pedal itself, though we wonder if the bare module could get slipped in there someplace. Of course you could always build your own pedal with a bit of extra room to fit the electronics, but for less than $2 USD on AliExpress, it’s hard to go wrong with this turn-key unit.

Looking for an alternate approach? We covered a Bluetooth page turner last month that doubled the inputs and packed it all into a handsome wooden enclosure.

Continue reading “This ESP32 Bluetooth Page Turner Can’t Get Any Easier” →

Finite Element Analysis Vs Real World

May 27, 2021 by 15 Comments

In advanced engineering circles, the finite element method — or, more commonly, finite element analysis — is a real staple. With the advent of more powerful home computers, though, even your home projects can benefit. The technique itself is very general, but you usually see it used for structural analysis. However, you might wonder how well it corresponds to reality. That is if analysis shows a segment of your part is weak (or strong) does that hold true when you actually build the part? [Fiveohno] wondered the same thing and decided to do some testing, which you can see in the video below.

Of course, like any simulation, the accuracy will only be as good as your data input and model. But if you work carefully, it should match up pretty well to the real world, so it is interesting to see the results of a real-world test. In fact, a video from Solidworks that shows a similar part points out — inadvertently — what not to do. For example, the force used in that analysis was too low and at a point where the part was at relatively low stress instead of at the maximum stress.

Continue reading “Finite Element Analysis Vs Real World” →

History Of Closed Captions: Entering The Digital Era

May 27, 2021 by 42 Comments

When you want to read what is being said on a television program, movie, or video you turn on the captions. Looking under the hood to see how this text is delivered is a fascinating story that stared with a technology called Closed Captions, and extended into another called Subtitles (which is arguably the older technology).

I covered the difference between the two, and their backstory, in my previous article on the analog era of closed captions. Today I want to jump into another fascinating chapter of the story: what happened to closed captions as the digital age took over? From peculiar implementations on disc media to esoteric decoding hardware and a baffling quirk of HDMI, it’s a fantastic story.

There were some great questions in the comments section from last time, hopefully I have answered most of these here. Let’s start with some of the off-label uses of closed captioning and Vertical Blanking Interval (VBI) data.

Continue reading “History Of Closed Captions: Entering The Digital Era” →

One Inkscape Plugin Collection To Rule Them All

May 27, 2021 by 40 Comments

Inkscape is an amazing piece of open source software, a vector graphics application that’s a million times more lightweight than comparable commercial offerings while coming in at the low, low price of free. The software also has plenty of extensions floating around on the Internet, though until now, they haven’t been organised particularly well. The MightyScape project aims to solve that, putting a bunch of Inkscape plugins into one useful release.

The current MightyScape release has a whole bunch of useful stuff inside, for tasks as varied as laser cutting, 3D printing, vinyl cutting, as well as improvements on areas where Inkscape is a bit weak out of the box – like CAD, geometry and patterning. The extensions are maintained and working, albeit with some bugs, and are intended for use with Inkscape 1.0 and above.

The aim is that by creating an overarching collection, the MightyScape project will help inspire the community to come together and actively maintain Inkscape plugins rather than allowing them to wither and die when forgotten by their original creators. That’s the benefit of open-source, after all – you can do whatever you want with the software when you have the code to do so!

Electric Vehicles Do Battle On Pikes Peak

May 27, 2021 by 61 Comments

When we think of electric cars, more often than not we’re drawn to the environmental benefits and the smooth quiet commuter drives they’re so ideally suited for. However, EVs can also offer screaming performance, most notably due to their instant-on torque that gives them a big boost over internal combustion vehicles.

In recent years, this has led to a variety of independent and manufacturer-supported efforts taking on some of motorsport’s classic events. Today, we’re looking at a handful of recent entries that have tackled one of the most gruelling events in motorsport – the Pikes Peak International Hillclimb. Continue reading “Electric Vehicles Do Battle On Pikes Peak” →

Samsung Releases Minimum Viable Galaxy Upcycling

May 27, 2021 by 30 Comments

It’s a tragedy every time a modern smartphone is tossed into e-waste. We prefer to find another life for these bundles of useful hardware. But given all the on-board barriers erected by manufacturers, it’s impractical to repurpose smartphones without their support. A bit of good news on this front is Samsung testing the waters with a public beta of their “Galaxy Upcycling at Home” program, turning a few select devices into SmartThings sensor nodes.

More devices and functionality are promised, but this initial release is barely a shadow of what Samsung promised in 2017. Missed the announcement back then? Head over to a “How it started/How it’s going” comparison from iFixit, who minced no words starting with their title Galaxy Upcycling: How Samsung Ruined Their Best Idea in Years. They saw a bunch of Samsung engineers at Bay Area Maker Faire 2017, showing off a bunch of fun projects reusing old phones as open hardware. The placeholder GitHub repository left from that announcement still has a vision of a community of makers dreaming up novel uses. This is our jam! But sadly it has remained a placeholder for four years and, given what we see today, it is more likely to be taken down than to become reality.

The stark difference between original promise and actual results feel like an amateur Kickstarter, not something from a giant international conglomerate. Possibly for the same reason: lack of resources and expertise for execution. It’s hard to find support in a large corporate bureaucracy when there is no obvious contribution to the bottom line. Even today’s limited form has only a tenuous link of possibly helping to sell other SmartThings-enabled smart home devices.

Ars Technica was similarly unimpressed with launch functionality, but was more diplomatic describing the beta as “a very modest starting point”. XDA-Developers likewise pinned their hopes on the “more devices will be supported in the future” part of Samsung’s announcement. Until Samsung delivers on more of the original promise, we’ll continue to be hampered by all the existing reasons hacking our old cell phones are harder than they should be. Sometimes an idea can be fulfilled by helpful apps but other times will require hacking into our devices the old-fashioned way.

WiFi Penetration Testing With An ESP32

May 27, 2021 by 13 Comments

WiFi is one of those technologies that most of us would have trouble living without. Unfortunately, there are several vulnerabilities in the underlying 802.11 standards that could potentially be exploited. To demonstrate just how simple this can be, [risinek] developed the ESP32 Wi-Fi Penetration Tool that runs on cheap dev boards and can execute deauthentication and Denial of Service attacks, and capture handshakes and PMKIDs.

The main challenge in this project is to implement these attacks while using the ESP-IDF development framework. The closed source WiFi libraries of the ESP-IDF block specific arbitrary frames like deauthentication frames. To get around this [risinek] used two different approaches. The first is to bypass the declaration of the blocking function at compile-time, which is borrowed from the esp32-deauther project. The second approach doesn’t require any modifications to the ESP-IDF. It works by creating a rogue access point (AP) identical to the targeted access point, which will send a deauthentication frame whenever one of the devices tries to connect to it instead of the real AP.

WPA/WPA2 handshakes are captured by passively listening for devices connecting to the target network, or running a deauth attack and then listening for when devices reconnect. PMKIDs are captured from APs with the roaming feature enabled, by analyzing the first message of a WPA handshake. ESP32 Wi-Fi Penetration Tool will also format the captured data into PCAP and HCCAPX files ready to be used with Wireshark and Hashcat. To manage the tool, it creates a management access point where the target and attack type is selected, and the resulting data can be downloaded. Pair the ESP32 with a battery, and everything can be done on the go. The project is part of [risinek]’s master’s thesis, and the full academic article is an educating read. Continue reading “WiFi Penetration Testing With An ESP32” →