LittleFS: The Emphasis Is On Little

October 4, 2023 by 15 Comments

It used to be that developing for microcontrollers was relatively relaxing. These days, even a cheap micro like the Raspberry Pi Pico has multiple cores, networking (for the W, at least), and file systems. Just like desktop computers. Sort of. I found out about the “sort of” part a few weeks ago when I decided to embark on a little historical project. I wanted a file system with a large file that emulates a disk drive. The Pico supports LittleFS, and I figured that would be the easy thing to do. Turns out the Little in LittleFS might be more literal than you think. On the plus side, I did manage to get things working, but it took a… well — dare I say hack? — to make it all work.

History

I’m an unabashed fan of the RCA 1802 CPU, which is, of course, distinctly retro. The problem is, I keep losing my old computers to moves, natural disasters, and whatnot. I’ve had several machines over the years, but they seem to be a favorite target of Murphy’s law for me. I do currently have a small piece of hardware called an Elf Membership Card (by [Lee Hart]), but it lacks fancy features like disk drives, and while it could be expanded, there’s something charming about its current small size. So that led me to repurpose a 6502 emulator for the KIM-1 to act like an 1802 instead. This is even less capable than the membership card, so it was sort of a toy. But I always thought I should upgrade the Arduino inside the emulator to a processor with more memory, and that’s what I did.

I started out with a Blackpill STM32F board and called the project 1802Black. The code is a little messy since it started out as [Oscar’s] KimUNO code, and then my updates layered with new updates. Also, for now, I shut off the hardware parts so it won’t use the KimUNO hardware — you only need a Blackpill (or a Pico, see below) and nothing else, although I may reenable the hardware integration later.

It wasn’t that hard to get it running with just more memory. Still, I wanted to run [Mike Riley’s] Elf/OS operating system and I also had a pair of Raspberry Pi Picos mocking me for not using them in a project yet. The chip has excellent Arduino board support. But what sealed the deal was noticing that you can partition the Pico’s flash drive to use some of it for your program and the rest for a file system. You can get other RP2040 dev boards with 16 MB of flash, which would let me have a nearly 15 MB “hard drive,” which would have been huge in the 1802’s day. Sounds simple. If it were, though, we wouldn’t be talking.

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Hackaday Prize 2023: The Wildcard Finalists Are Here

October 4, 2023 by 5 Comments

We’re in the endgame now — there’s just about a month to go before the final results are announced for the 2023 Hackaday Prize, which means all of our finalists are in a mad rush to put the finishing touches on their respective projects. Today, ten more hackers are about to feel the heat as we announce our final group of finalists from the Save the World Wildcard round.

As finalists, each of these projects has been awarded $500 to help further their development. But perhaps more importantly, they are now officially in the running for one of the final six awards, which includes the Grand Prize of $50,000 and a residency at the Supplyframe DesignLab.

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Autonomous Wheelchair Lets Jetson Do The Driving

October 4, 2023 by 8 Comments

Compared to their manual counterparts, electric wheelchairs are far less demanding to operate, as the user doesn’t need to have upper body strength normally required to turn the wheels. But even a motorized wheelchair needs some kind of input from the user to control it, which still may pose a considerable challenge depending on the individual’s specific abilities.

Hoping to improve on the situation, [Kabilan KB] has developed a self-driving electric wheelchair that can navigate around obstacles by feeding the output of an Intel RealSense Depth Camera and LiDAR module into a Jetson Nano Developer Kit running OpenCV. To control the actual motors, the Jetson is connected to an Arduino which in turn is wired into a common L298N motor driver board.

As [Kabilan] explains on the NVIDIA Blog, he specifically chose off-the-shelf components and the most affordable electric wheelchair he could find to bring the total cost of the project as low as possible. An undergraduate from the Karunya Institute of Technology and Sciences in Coimbatore, India, he notes that this sort of assistive technology is usually only available to more affluent patients. With his cost-saving measures, he hopes to address that imbalance.

While automatic obstacle avoidance would already be a big help for many users, [Kabilan] imagines improved software taking things a step further. For example, a user could simply press a button to indicate which room of the house they want to move to, and the chair could drive itself there automatically. With increasingly powerful single-board computers and the state of open source self-driving technology steadily improving, it’s not hard to imagine a future where this kind of technology is commonplace.

Robotic Mic Swarm Helps Pull Voices Out Of Crowded Room Of Multiple Speakers

October 4, 2023 by 27 Comments

One of the persistent challenges in audio technology has been distinguishing individual voices in a room full of chatter. In virtual meeting settings, the moderator can simply hit the mute button to focus on a single speaker. When there’s multiple people making noise in the same room, though, there’s no easy way to isolate a desired voice from the rest. But what if we ‘mute’ out these other boisterous talkers with technology?

Enter the University of Washington’s research team, who have developed a groundbreaking method to address this very challenge. Their innovation? A smart speaker equipped with self-deploying microphones that can zone in on individual speech patterns and locations, thanks to some clever algorithms.

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Roll Your Own Servo

October 4, 2023 by 51 Comments

Usually, when you want a servo motor, you simply buy one already made. But if you need something unusual, you can turn any DC motor into a custom servo you can control just like [Dejan] did. You can watch a video of the process below.

The custom servo can tune the endpoints, the center point, and the sensitivity. It also can be set to handle continuous rotation. A 12-bit encoder tells the microcontroller where the motor is and the output drivers can handle over 3 A of motor current. The microprocessor is a tried-and-true ATmega328. [Dejan] wanted to make the board as small as possible, and we think 40 mm square isn’t bad at all. There is also a 3D printed gearbox and housing. Overall, a very well-done project.

The motor control uses a PID algorithm. Potentiometers set the end range and sensitivity. A push button allows resetting the center position. DIP switches control the mode. The video shows a computer and an RC controller setting the position of the motors.

We have, of course, seen many variations on this idea. We’ve also seen servos rebuilt for better performance.

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ARPA-H Moonshot Project Aims To Enable 3D Printing Of Human Organs

October 4, 2023 by 9 Comments

The field of therapeutic cloning has long sought to provide a way to create replacement organs and tissues from a patient’s own cells, with the most recent boost coming from the US Advanced Research Projects Agency for Health (ARPA-H) and a large federal contract awarded to Stanford University.

Patients on the organ donation waiting list in the US (Source: HRSA)
Patients on the organ donation waiting list in the US (Source: HRSA)

The creatively named Health Enabling Advancements through Regenerative Tissue Printing (HEART) project entails a 26.3 million USD grant that will be used to create a functioning bioprinter backed by a bank of bioreactors. Each bioreactor will cultivate a specific type of cell, which will then be ‘printed’ in its proper place to gradually build up the target organ or tissue. The project’s five year goal is the printing of a fully functioning human heart and implanting it into a pig.

Assuming this is successful, the general procedure can then be refined to allow for testing with human patients, as well as the bioprinting of not just hearts, but also lungs, kidneys and much more. The lead investigator at Stanford University, [Mark Skylar-Scott], cautions that use with human patients is likely to be still decades off. But the lifesaving potential of this technology, once matured, is staggering. This is highlighted by data from the US HRSA, with over 42,000 transplants in 2022 in the US alone, with over a hundred-thousand patients waiting and 17 people who die each day before an organ becomes available.

Peggyboard Will Have You Climbing The Walls Repeatedly

October 3, 2023 by 2 Comments

When you can’t climb actual rocks all the time, what do you do to train and keep sharp? You go to a rock-climbing gym, naturally. But what do you do when it’s 2020 and your rock-climbing gym has shuttered for the foreseeable? You build the best darn rock-climbing wall possible, and you outfit it with an LED for every hold and write an app that lets you plan your route and repeat it later.

This is essentially a DIY version of something called a Moonboard, which, aside from being expensive, was quickly going out of stock back in 2020. [Pegor] started the Peggyboard by building a climbing woody, which is a legendary home climbing wall built by a legendary climber about 20 years ago.

The Peggyboard is Raspberry Pi-powered and has a rather nice app going for it, which [Pegor] has kindly decided to open source.

On the initial screen, the user can select a route and assign the holds as either starting holds, foot holds, hand holds, or finishing holds, each with a different color LED. Another screen lets the user choose a previously-saved route, then apply it to the Peggyboard’s LEDs with the light bulb icon.

Don’t know where to get started building your own climbing wall? You can 3D print climbing holds, you know.