We’ve all found ourselves swimming amongst too many similar-looking USB cables over the years. Some have all the conductors and functionality, some are weird power-only oddballs, and some charge our phones quickly while others don’t. It’s a huge headache and one that [TechKiwiGadgets] hopes to solve with the Arduino Cable Tracer.
The tracer works with USB-A, Mini-USB, Micro-USB, and USB-C cables to determine whether connections are broken or not and also to identify wiring configurations. It’s built around the Arduino Mega 2560, which is ideal for providing a huge amount of GPIO pins that are perfect for such a purpose. Probing results are displayed upon the 2.8″ TFT LCD display that makes it easy to figure out which cables do what.
For retro gaming, there’s really no substitute for original hardware. As it ages, though, a lot of us need to find something passable since antique hardware won’t last forever. If a console isn’t working properly an emulator can get us some of the way there, but using an original controller is still preferred even when using emulators. To that end, [All Parts Combined] shows us how to build custom interfaces between original Nintendo controllers and a PC.
The build starts by mapping out the controller behavior. Buttons on a SNES controller don’t correspond directly to pins, rather a clock latches all of the button presses at a particular moment all at once during each timing event and sends that information to the console. To implement this protocol an Adafruit Trinket is used, and a thorough explanation of the code is given in the video linked below. From there it was a simple matter of building the device itself, for which [All Parts Combined] scavenged controller ports from broken Super Nintendos and housed everything into a tidy box where it can be attached via USB to his PC.
While it might seem like a lot of work to get a custom Nintendo controller interface running just because he had lost his Mega Man cartridge, this build goes a long way to understanding a custom controller protocol. Plus, there’s a lot more utility here than just playing Mega Man; a method like this could easily be used to interface other controllers as well. We’ve even seen the reverse process where USB devices were made to work on a Nintendo 64.
It turns out that PS/2 and USB are very, very different. A PS/2 keyboard sends your keystroke every time you press a key, as long as it has power. A USB keyboard is more polite, it won’t send your keystrokes to the PC until it asks for them.
To help us make sense of USB’s more complicated transactions, [Ben] prints out the oscilloscope trace of a USB exchange between a PC and keyboard and deciphers it using just a pen and the USB specification. We were surprised to see that USB D+ and D- lines are not just a differential pair but also have more complicated signaling behavior. To investigate how USB handles multi-key rollover, [Ben] even borrowed a fancy oscilloscope that automatically decodes the USB data packets.
It turns out that newer isn’t always better—the cheap low-speed USB keyboard [Ben] tested is much slower than his trusty PS/2 model, and even a much nicer keyboard that uses the faster full-speed USB protocol is still only just about as fast as PS/2.
If you’d like to delve deeper into keyboard protocols, check out [Ben]’s guide to the PS/2 keyboard interface, complete with a breadboarded hardware decoder. If these keyboards have too many keys for your taste, you might consider this USB Morse code keyboard. Thanks to Peter Martin for the Tip!
If you’re looking for a quick and easy way to control a few devices from your computer, a cheap USB relay board might be the ideal solution. These are fairly simple gadgets, consisting of little more than a microcontroller and a handful of relays. But that doesn’t mean there isn’t room for improvement, and as [Michał Słomkowski] recently demonstrated, flashing these boards with a custom firmware allows the user to modify their default functionality.
In his case, [Michał] wanted to build a power strip that would cut the power to any devices plugged into it once his computer went to sleep. Unfortunately, he couldn’t just check to see if there was 5 V on the line as his motherboard kept the USB ports powered up all the time. But with some modifications to the relay board’s firmware, he reasoned he should be able to detect if there was any USB activity by watching for the start-of-frame packet that goes out every millisecond when the bus is active.
Wiring up the ATtiny45 for flashing.
Now [Michał] isn’t claiming to be the first person to come up with a custom firmware for one of these boards, in fact, he credits an existing open source firmware project as an inspiration for his work. But he did create an entirely new GPLv3 firmware for these ATtiny45 powered devices, which includes among other improvements the latest version of V-USB. As it so happens, V-USB includes start-of-frame packet detection out of the box, which made it much easier to implement his activity detection code.
With the new firmware flashed to the relay board’s chip, [Michał] put it in an enclosure and wired up the outlets. But there was still one missing piece of the puzzle. It seems that Linux won’t actually send out the start-of-frame packets unless its actively communicating with a USB device, as part of the so-called “selective suspend” power saving feature. Luckily there is support for disabling this feature for specific devices based on their Vendor/Product ID pair, so after a little udev fiddling, everything was working as expected.
Is it really cheating if the aimbot you’ve built plays the game worse than you do?
We vote no, and while we take a dim view on cheating in general, there are still some interesting hacks in this AI-powered bot for Valorant. This is a first-person shooter, team-based game that has a lot of action and a Counter-Strike vibe. As [River] points out, most cheat-bots have direct access to the memory of the computer which is playing the game, which gives it an unfair advantage over human players, who have to visually process the game field and make their moves in meatspace. To make the Valorant-bot more of a challenge, he decided to feed video of the game from one computer to another over an HDMI-to-USB capture device.
The second machine has a YOLOv5 model which was trained against two hours of gameplay, enough to identify friend from foe — most of the time. Navigation around the map was done by analyzing the game’s on-screen minimap with OpenCV and doing some rudimentary path-finding. Actually controlling the player on the game machine was particularly hacky; rather than rely on an API to send keyboard sequences, [River] used a wireless mouse dongle on the game machine and a USB transmitter on the second machine.
The results are — iffy, to say the least. The system tends to get the player stuck in corners, and doesn’t recognize enemies that pop up at close range. The former is a function of the low-res minimap, while the latter has to do with the training data set — most human players engage enemies at distance, so there’s a dearth of “bad breath range” encounters to train to. Still, we’re impressed that it’s possible to train a machine to play a complex FPS game at all, let alone this well.
Since the ESP8266 came on the scene a few years ago and revolutionized the way microcontrollers communicate with other devices, incremental progress on this chip has occurred at a relatively even pace. First there was the realization that code could be run on the chip itself. Next the ESP32 was released which built more on that foundation. The next step in that process of improvement may be here now as well, with this project which turns the ESP32 into a USB host.
USB is not a native feature on all microcontrollers or even Arduino-compatible boards. While some do have it built in like those based on the 32u4 for example, most either don’t have it at all or rely on a separate on-board chip to do some form of translating. The ESP32 is lacking this advanced feature so the USB needs to be cobbled together from scratch if you want this specific board to be able to interface directly with peripherals. This project does just that, allowing for four USB 1.1 devices to be connected directly to the ESP32 without a separate dedicated chip.
If you’ve been waiting for USB on this tiny, capable microcontroller this might be your chance to try it out. All of the project’s code is available on the project page. And, while it is limited in scope, it’s easily able to handle a keyboard or mouse. This might be a more cost-effective way of doing something like a KVM switch rather than doing it with three Arduinos.
For years, one of the most accessible and simplest-to-implement methods of talking to a dev board has been to give it a serial port. Almost everything has serial in some form, so all that’s needed is to fire up a terminal. But even with that simplicity, there are still moments when the end user might find a terminal interface a little daunting. Think of a board aimed at kids for example, or an event badge which must be accessible to as many people as possible.
We’ve seen a very convenient solution to this problem in the form of WebUSB, but for devices without the appropriate USB hardware there’s WebSerial, an in-browser API for communicating with serial ports including USB-to-serial chips. [Tom Clement] argues that this could serve as the way forward for event badges. Best of all it can be a retro-fit to enable in-browser development for older badges or dev boards with a serial port.
The boards on which he demonstrates the technique are the series of event badges running the badge.team firmware platform including his own i-Pane from CampZone 2019 and going right back to the SHA 2017 badge, but there’s no reason why the same technique can’t be extended to other boards.
There’s a snag with all this though, sadly only browsers in the Chrome family support it at the time of writing, with no plans from Mozilla and apple, and silence from Microsoft. So things look likely to stay that way. It is however inevitable that in time there will be commercial products taking advantage of it via the use of cheap USB to serial chips, so perhaps the case to incorporate it will make itself.
