There are a number of reasons you might want to build your own smart speaker virtual assistant. Usually, getting your weather forecast from a snarky, malicious AI potato isn’t one of them, unless you’re a huge Portal fan like [Binh Pham].
[Binh Pham] built the potato incarnation of GLaDOS from the Portal 2 video game with the help of a ReSpeaker Light kit, an ESP32-based board designed for speech recognition and voice control, and as an interface for home assistant running on a Raspberry Pi.
He resisted the temptation to use a real potato as an enclosure and wisely opted instead to print one from a 3D file he found on Thingiverse of the original GLaDOS potato. Providing the assistant with the iconic synthetic voice of GLaDOS was a matter of repackaging an existing voice model for use with Home Assistant.
Of course all of this attention to detail would be for not if you had to refer to the assistant as “Google” or “Alexa” to get its attention. A bit of custom modelling and on-device wake word detection, and the cyborg tuber was ready to switch lights on and off with it’s signature sinister wit.
Another day, another Internet-connected gadget that gets abandoned by its creators. This time it’s Jooki — a screen-free audio player that let kids listen to music and stories by placing specific tokens on top of it. Parents would use a smartphone application to program what each token would do, and that way even very young children could independently select what they wanted to hear.
Well, until the company went bankrupt and shutdown their servers down, anyway. Security researcher [nuit] wrote into share the impressive work they’ve done so far to identify flaws in the Jooki’s firmware, in the hopes that it will inspire others in the community to start poking around inside these devices. While there’s unfortunately not enough here to return these devices to a fully-functional state today, there’s several promising leads.
It probably won’t surprise you to learn the device is running some kind of stripped down Linux, and [nuit] spends the first part of the write-up going over the partitions and peeking around inside the filesystem. From there the post briefly covers how over-the-air (OTA) updates were supposed to work when everything was still online, which may become useful in the future when the community has a new firmware to flash these things with.
Where things really start getting interesting is when the Jooki starts up and exposes its HTTP API to other devices on the local network. There are some promising endpoints such as /flags which let’s you control various aspects of the device, but the real prize is /ll, which is a built-in backdoor that runs whatever command you pass it with root-level permissions! It’s such a ridiculous thing to include in a commercial product that we’d like to think they originally meant to call it /lol, but in any event, it’s a huge boon to anyone looking to dig deeper in to the device.
The inside of a second-generation Jooki
But wait, there’s more! The Jooki runs a heartbeat script that regularly attempts to check in with the mothership. The expected response when the box pings the server is your standard HTTP 200 OK, but in what appears to be some kind of hacky attempt at implementing a secondary OTA mechanism, any commands sent back in place of the HTTP status code will be executed as root.
Now as any accomplished penguin wrangler will know, if you can run commands as root, it doesn’t take long to fire up an SSH server and get yourself an interactive login. Either of these methods can be used to get into the speaker’s OS, and as [nuit] points out, the second method means that whoever can buy up the Jooki domain name would have remote root access to every speaker out there.
Long story short, it’s horrifyingly easy to get root access on a Jooki speaker. The trick now is figuring out how this access can be used to restore these devices to full functionality. We just recently covered a project which offered a new firmware and self-hosted backend for an abandoned smart display, hopefully something similar for the Jooki isn’t far off.
The loudspeaker on your home entertainment equipment is designed to project audio around the space in which it operates, if it’s not omnidirectional as such it can feel that way as the surroundings reflect the sound to you wherever you are. Making a directional speaker to project sound over a long distance is considerably more difficult than making one similar to your home speaker, and [Orange_Murker] is here with a solution. At the recent Hacker Hotel conference in the Netherlands, she presented an ultrasonic parametric speaker. It projects an extremely narrow beam of sound over a significant distance, but it’s not an audio frequency speaker at all.
Those of you familiar with radio will recognize its operation; an ultrasonic carrier is modulated with the audio to be projected, and the speaker transfers that to the air. Just like the diode detector in an old AM radio, air is a nonlinear medium, and it performs a demodulation of the ultrasound to produce an audio frequency that can be heard. She spends a while going into modulation schemes, before revealing that she drove her speaker with a 40 kHz PWM via an H bridge. The speaker itself is an array of in-phase ultrasonic transducers, and she demonstrates the result on her audience.
When building one-off projects, it’s common to draw up a plan on a sheet of paper or in CAD, or even wing it and hope for the best outcome without any formal plans. Each of these design philosophies has its ups and downs but both tend to be rigid, offering little flexibility as the project progresses. To solve this, designers often turn to parametric design where changes to any part of the design are automatically reflected throughout the rest, offering far greater flexibility while still maintaining an overall plan. [Cal Bryant] used this parametric method to devise a new set of speakers for an office, with excellent results.
The bulk of the speakers were designed with OpenSCAD, with the parametric design allowing for easy adjustments to accommodate different drivers and enclosure volumes. A number of the panels of the speakers are curved as well, which is more difficult with traditional speaker materials like MDF but much easier with this 3D printed design. There were a few hiccups along the way though; while the plastic used here is much denser than MDF, the amount of infill needed to be experimented with to achieve a good finish. The parametric design paid off here as well as the original didn’t fit exactly within the print bed, so without having to split up the print the speakers’ shape was slightly tweaked instead. In the end he has a finished set of speakers that look and sound like a high-end product.
There are a few other perks to a parametric design like this as well. [Cal] can take his design for smaller desk-based speakers and tweak a few dimensions and get a model designed to stand up on the floor instead. It’s a design process that adds a lot of options and although it takes a bit more up-front effort it can be worth it while prototyping or even for producing different products quickly. If you want to make something much larger than the print bed and slightly changing the design won’t cut it, [Cal] recently showed us how to easily print huge objects like arcade cabinets with fairly standard sized 3D printers.
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