Building a robot arm is fun, but no longer the challenge it once was. You can find lots of plans and kits, and driving the motors is a solved problem. However, there is always one decision you have to make that can be a challenge: what effector to put on the end of it. If you are [MertArduino] the answer is to put suction at the end. If you need to grab the right things, this could be just the ticket for reliably lifting and letting go. You can see a video of the arm in action, below.
The arm itself is steel with four servo motors and comes in a kit. The video shows the arm making a sandwich under manual control. We suspect he might have put it under Arduino control but there’s no sudo for making sandwiches.
According to [Mike Walters], the Elgato Cam Link 4K is a great choice if you’re looking for a HDMI capture device that works under Linux. But the bad news is, it wouldn’t work with any of the video conferencing software he tried to use it with because they expect the video stream to be in a different pixel format. For most people, that would probably have been the end of the story. But you’re reading this on Hackaday, so obviously he didn’t give up without a fight.
Early on, [Mike] found there was a software workaround for this exact issue. The problem isn’t that the Elgato can’t generate the desired format, it’s that the video conferencing programs just don’t know how to ask it to switch modes. The software fix is to create a dummy Video4Linux device and use that to change the format in real-time using ffmpeg. It’s a clever trick if you’ve got a conference call coming up in a few minutes, but it does waste CPU resources and adds some unnecessary hoop jumping.
Putting the device into bootloader mode.
Inspired by the software fix, [Mike] wondered if there was a way he could simply force the Elgato to output video in the desire format by default. He found a firmware dump for the device online, and found where the pixel formats were referenced by searching for their names in ASCII with hexdump. Looking through the source for the Linux USB Video Class (UVC) driver, he was then able to determine what the full 16 byte sequence should be for each video mode was so he could zero out the unwanted ones. Then it was just a matter of flashing his modified firmware back to the hardware.
But there was a problem: with the modified firmware installed, the device stopped working. After investigating the obvious culprits, [Mike] broke out the oscilloscope and hooked it up to the Elgato’s flash chip. It turns out that due to a bug in the program he was using, the SPI erase commands weren’t getting sent during the flash. This lead to corrupted firmware which was keeping the Elgato from booting. After making a pull request with his fixes, the firmware flashed without incident and the capture device now does double-duty as a webcam when necessary.
We could certainly think of easier and quicker was to roll your own webcam, but we’re glad that [Mike] took the time to modify his Elgato Cam Link 4K and document it. It’s a fantastic example of practical firmware hacking, even if you’re not in the market for a new high-definition video conferencing rig.
Hardware support under Linux is far better than it ever has been in the past. These days, most things “just work” out of the box, and you probably won’t have to compile any custom kernel modules. Certainly a far cry from where things were a decade ago. But that doesn’t mean everything will work to 100% of its abilities. Take for example, the Duck keyboard that [Cynthia Revström] has. Sure it works as a basic keyboard under any OS, but getting those fancy RGB LEDs working is another story entirely.
Don’t get the wrong idea here, [Cynthia] isn’t just trying to get the keyboard to flash along to music; the goal was to use the RGB lighting of the Ducky keyboard for notifications that the user can’t possibly ignore. Even the most laser-focused among us would have a hard time not noticing that the entire keyboard is blinking red. But the “DuckyRGB” software that you need to do something like that is Windows-only and apparently distributed via a sketchy Google Drive link. Yikes.
The first step to creating an alternative was to spin up a Windows VM and install DuckyRGB. From there, Wireshark could listen in between the virtual computer and the Ducky keyboard to see what the software was sending over the wire. After identifying a version number being sent in the clear, [Cynthia] was able to isolate the LED commands by searching for the hex color codes. From there, it was a relatively simple matter of writing some glue code to connect it up to an alert service and get notifications going.
There was only one problem; the keyboard didn’t work anymore. Turns out the tool that [Cynthia] wrote to control the keyboard’s LEDs was claiming the device so the kernel couldn’t access it for normal input. It took a detour with HIDAPI to get everyone playing together nicely, and now changing the color of your Ducky keyboard on Linux doesn’t turn it into a paperweight.
Even if you don’t have a Ducky keyboard, or aren’t particularly interested in having its LEDs blinked at you if you do, this project is a phenomenal example of practical USB reverse engineering. [Cynthia] says the inspiration for this project came from friend [Ben Cox], who’s write-up on creating USB userspace drivers we covered last year. If you’ve got and old USB gadget with Windows-only drivers, maybe it’s time you take a crack at unlocking it.
Many of the SDR projects we see use a cheap USB dongle. They are great, but sometimes you want more and — especially — sometimes you want to transmit. The Analog Devices ADALM-Pluto SDR is easily available for $200 and sometimes as low as $100 and it both transmits and receives using an Analog AD9363 and a Zynq FPGA. Although you normally use the device to pipe IQ signals to a host computer, you can run SDR applications on the device itself. That requires you to dig into the Zynq tools, which is fun but a topic for another time. In this post, I’m going to show you how you can use GNU Radio to make a simple Morse code beacon in the 2m ham band.
I’ve had one on my bench for quite a while and I’ve played with it a bit. There are several ways to use it with GNU Radio and it seems to work very well. You have to hack it to get the frequency range down a bit. Sure, it might not be “to spec” once you broaden the frequency range, but it seems to work fine. Instead of working from 325 MHz to 3,800 MHz with a 20 MHz bandwidth, the hacked device transceives 70 MHz to 6,000 MHz with 56 MHz bandwidth. It is a simple hack you only have to do once. It tells the device that it has a slightly better chip onboard and our guess is the chips are the same but sorted by performance. So while the specs might be a little off, you probably won’t notice.
The printed circuit design process is pretty unique among manufacturing processes. Chances are pretty good that except for possibly a breadboard prototype, the circuit that sits before you after coming back from assembly has only ever existed in EDA software or perhaps a circuit simulator. Sure, it’s supposed to work, but will it?
You can — and should — do some power-off testing of new boards, but at some point you’re going to have to flip the switch and see what happens. The PCB bring-up process needs to be approached carefully, lest debugging any problems that crop up become more difficult than need be. Mihir and Liam from inspectAR will discuss the bring-up process in depth, offering tips and tricks to make things go as smoothly as possible, as well as demonstrating how the inspectAR platform can fit into that process, especially with teams that are distributed across remote sites. If your board releases the Magic Smoke, you’ll want to know if it’s your design or an assembly issue, and an organized bring-up plan can be a big help.
Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.
People keep saying that time has lost all meaning now, but we’re still over here divvying up the days with hacks. Most of the hacks you see here are open source. But if you want something even more transparent to meter out the meaninglessness, we invite you to make one of these clearly awesome see-through clocks, which happens to be both.
A word of warning though — according to [GeekMomProjects], this is an incredibly fiddly build with tight tolerances everywhere that acrylic meets acrylic or an LED strip. We can see how it might be like forcing fragile puzzle pieces together. Since the whole thing is crystal clear acrylic, light is going to go everywhere.
[GeekMomProjects] cleverly blocked the escaping light by painstakingly applying non-conductive adhesive foil to the edges of all the smaller pieces. In spite of all that work, we think it would be worth it to have such a fantastic timepiece glowing away the hours somewhere in the house.
Electronically speaking, this beauty is pretty simple. The lights run off of an ItsyBitsy M4 Express, and the time is separately fetched with an ESP8266. [GeekMomProjects] had so much fun that she made one with seconds and one without. Check out their RGB dance routine after the break.
The current COVID-19 pandemic is rife with problems that hackers have attacked with gusto. From 3D printed face shields and homebrew face masks to replacements for full-fledged mechanical ventilators, the outpouring of ideas has been inspirational and heartwarming. At the same time there have been many efforts in a different area: research aimed at fighting the virus itself.
Getting to the root of the problem seems to have the most potential for ending this pandemic and getting ahead of future ones, and that’s the “know your enemy” problem that the distributed computing effort known as Folding@Home aims to address. Millions of people have signed up to donate cycles from spare PCs and GPUs, and in the process have created the largest supercomputer in history.
But what exactly are all these exaFLOPS being used for? Why is protein folding something to direct so much computational might toward? What’s the biochemistry behind this, and why do proteins need to fold in the first place? Here’s a brief look at protein folding: what it is, how it happens, and why it’s important.
