Day: December 27, 2022

All About USB-C: Illegal Adapters

December 27, 2022 by 106 Comments

Let’s be clear – it’s not enough to have USB-C to USB-C cables. There’s a lot of cables that we might want to acquire for our day-to-day use, perhaps, for a transition period while we still own some amount of devices not adorned with a USB-C connector. However, the USB-C specification only accounts for a limited amount of kinds of cables, explicitly or implicitly excluding a range of cables that you might want to buy or make.

It’s my firm belief that, as a hacker, you should be able to buy any USB-C contraption that you could ever need. Hackers don’t need restrictions driven by marketing – they need understanding of how a piece of tech can or cannot be used, based on how it operates internally. I would like you to provide with such understanding, so that you can make informed decisions.

On the other hand, USB-C is designed to be used by less-than-skilled people, even if it often fails at that. (Cable labelling, anyone?) Clear definitions of what complies to a standard can help enforce it. Here’s the notorious story of a USB-C cable that killed a Chromebook, and launched a career of explaining USB-C specifics online for [Benson Leung]. There’s many such failure stories, in fact. Today, we’ll go through USB-C contraptions which might or might not fail you, depending on how you use them. Continue reading “All About USB-C: Illegal Adapters” →

A collage of three images. On top is the main PCB of the headphones, with a charger IC and the main MCU. On the bottom left, it shows ACOK and EN signals going to pullup resistors near the MCU. On bottom right, it shows the charger chip with its pinout overlaying it, highlighting the pads to be probed and later cut.

One Hacker’s Battle To Slightly Improve A Sadistic Sony Headset

December 27, 2022 by 48 Comments

One thing you won’t read in reviews of pricey Sony WH-1000XM3 headphones – if you choose them, you’re going to find yourself in a one-sided abusive relationship. A button press or low-battery notification makes the headphones scream at you, ignoring the actual sound volume of what you’re currently listening to. Once they’re discharged, they suddenly emit loud noises, lecture you about how the battery is low, then shut down. Oh, and you can’t use them as they’re charging – if your voicecall lasts longer than expected, you might find yourself being shouted at and forced to fumble around with wires, silently pleading for call participants to wait while you change over to a different headset.

On-PCB footprint for the IC, with two pads carefully cut in half as mentioned in the article[MisterHW] decided to dig in and figure out how to work around at least some of the shortcomings. Naturally, the “no charge while using” limit looked like low-hanging fruit, and a hefty usability improvement too – plus, he suspected the charge cutoff to be masking noise issues already abundant on these headphones. Some painful disassembly later, he was inspecting the charger IC , the MP2625, responsible for power management. Its signals were connected to the MCU using via-in-pad – and some pads had to be cut in half to disconnect the vias.

However, the laborious pad cutting and subsequent careful soldering didn’t turn out to be fruitful. Even with external control of the output inhibition pins, the shutoff still continued – something affected the circuit, whether it was VBUS detection, some other unnoticed via-connected pins on the charger, or sensing on D+/D-. About to run out of life force for this mod, [MisterHW] added a Qi charging circuit, powering a TP4056 wired in parallel with the MP2625. The mod, dubbed HW-1000XM3, made these headphones all that more reliable and less annoying – charger and MCU none the wiser.

Now, all that’s needed to charge these headphones is to slap a magnetic charger coil onto them, and it doesn’t interfere with voicecalls as much as the screaming and forced shutoffs do. Hopefully, Sony eventually learns to test their headphones by having humans use them – it’s far from the only gripes with this lineup, after all. We also hope that the voice notifications will be conquered eventually – this summer, we’ve seen a hacker firmware mod a Bluetooth speaker to make the sounds more pleasant. If your headphones are based on a relatively popular module, repurposing them might be even easier than that!

A DIY self-balancing robot

3D-Printed Self-Balancing Robot Brings Control Theory To Life

December 27, 2022 by 8 Comments

Stabilizing an inverted pendulum is a classic problem in control theory, and if you’ve ever taken a control systems class you might remember seeing pages full of differential equations and bode diagrams just to describe its basic operation. Although this might make such a system seem terribly complicated, actually implementing all of that theory doesn’t have to be difficult at all, as [Limenitis Reducta] demonstrates in his latest project. All you need is a 3D printer, some basic electronic skills and knowledge of Python.

The components needed are a body, two wheels, motors to drive those wheels and some electronics. [Limenitis] demonstrates the design process in the video below (in Turkish, with English subtitles available) in which he draws the entire system in Fusion 360 and then proceeds to manufacture it. The body and wheels are 3D-printed, with rubber bands providing some traction to the wheels which would otherwise have difficulty on slippery surfaces.

A PCB driving two stepper motors
The PCB has just a few components, with most of the complexity handled by plug-in modules.

Two stepper motors drive the wheels, controlled by a DRV8825 motor driver, while an MPU-9250 accelerometer and gyroscope unit measures the angle and acceleration of the system. The loop is closed by a Raspberry Pi Pico that implements a PID controller: another control theory classic, in which the proportional, integral and derivative parameters are tuned to adapt the control loop to the physical system in question. External inputs can be provided through a Bluetooth connection, which makes it possible to control the robot from a PC or smartphone and guide it around your living room.

All design files and software are available on [Limenitis]’s GitHub page, and make for an excellent starting point if you want to put some of that control theory into practice. Self-balancing robots are a favourite among robotics hackers, so there’s no shortage of examples if you need some more inspiration before making your own: you can build them from off-the-shelf parts, from bits of wood, or even from a solderless breadboard.

Continue reading “3D-Printed Self-Balancing Robot Brings Control Theory To Life” →