A weighing scale with a moving-coil meter as a display

Hackaday Prize 2022: Arduino-Powered Weighing Scale Has A Real Analog Display

July 25, 2022 by Robin Kearey 3 Comments

Digital displays are useful for quick and accurate readout, but lots of people prefer the physical motion of a needle moving along a dial. For instance, many smartwatch users choose an analog face to show the time, and modern cars with digital dashboards often default to showing an analog speedometer. Following this trend, [Miro Pavleski] built a digital weighing scale with an analog display that not only looks neat, but also serves as a good demonstration of the way that modern scales work.

Inside, the device is built up like a typical electronic scale: the heart of the instrument is a load cell that supports the platform and bends in proportion to the weight applied. This bending motion is sensed by a set of strain gauges wired up in a Wheatstone bridge configuration. An HX711 readout chip measures the resulting voltage and converts it to a digital code that is sent to a microcontroller, in this case an Arduino Nano.

Whereas a typical scale would then simply show the resulting number on an LCD display, [Mirko] decided to use a moving coil meter driven by the Arduino’s analog output. That meter was originally designed to show currents, so [Mirko] printed a new background image using kilograms instead.

Continue reading “Hackaday Prize 2022: Arduino-Powered Weighing Scale Has A Real Analog Display” →

Don’t Miss Your Last Chance To Enter The Hack It Back Challenge

July 21, 2022 by Tom Nardi 3 Comments

While the 2022 Hackaday Prize as a whole winds its way through a good chunk of the year, each individual challenge that makes up the competition only sticks around for a limited time. As hard as it might be to believe, our time with theHack it Back challenge is nearly at a close, with just a few days left to enter your project before the July 24th deadline.

Each challenge in this year’s Hackaday Prize has been designed around the core themes of sustainability, resiliency, and circularity — and for the Hack it Back phase of the competition we asked hackers to essentially keep as much hardware out of the landfill as possible. That could mean making a simple fix that puts a piece of equipment back into service, or it might be a be complete rebuild of an older device to bring it up to modern standards. These are the kind of projects Hackaday was built on, so turning it into an official challenge this year made perfect sense. Continue reading “Don’t Miss Your Last Chance To Enter The Hack It Back Challenge” →

The printer in question - it's tall, about a meter and a half tall, in fact!

Hackaday Prize 2022: $40k Stratasys Printer Fix Costs $1

July 19, 2022 by Arya Voronova 36 Comments

Companies don’t treat equipment in the same way that we, hobbyists, do. When it comes to reassessing equipment state, there’s calculations to be done – how many failures it’s experienced, what’s the rate of the support contract for it (often increasing as equipment ages), and whether it’d be more price-efficient to just buy a new one. Hobbyists aren’t tied to commercial support contracts that prohibit DIY repair, however. We can investigate things and try our luck, and in many cases, the repair will be super simple and satisfying! Today’s lucky repair story is about [Gregor], who has acquired a written-off ±$40k Stratasys 3D printer for peanuts, and repaired it with $1 in parts.

The error code shown on the display indicated an extruder changer error — yes, this is a dual extruder printer! Earlier, [Gregor] noted that some of the chamber lighting LEDs failed, very likely because of the constant heat in the chamber. After investigating the infrared LED responsible for extruder change detection, it indeed had failed as well, presumably for the same reason. After the installation of a new SMD LED, the error message went away. Thus concludes the story of [Gregor] getting himself a new professional-grade printer! He also documents other possible failure modes, some just as easy to fix. In short, if you ever spot a Stratasys Dimension printer for sale, you might want to consider it!

As it turns out, this isn’t the only Stratasys success story we’ve seen on Hackaday.io. After you’ve repaired your newly obtained Stratasys, you might want to bypass the cartridge DRM, by the way. Got repairs of your own to share, industrial printer or otherwise? Submit it for the 2022 Hackaday Prize, there’s still a few days left in the Hack it Back round!

Hackaday Prize 2022: MasterPi Is A Capable Robot With Fancy Wheels

July 1, 2022 by Lewin Day 2 Comments

When it comes to building a mobile robot, often maneuverability is more important than outright speed. The MasterPi robot demonstrates this well, using fancy wheels to help it slide and skate in any direction needed.

Four DC gear-motors are fitted to a metal chassis, each one driving a mecanum wheel. These are special wheels with rollers fitted around their circumference at an angle that allows the robot to move in all directions and rotate in various ways depending on how each wheel is driven.

On top of this highly maneuverable chassis is placed a 5-degree-of-freedom robotic arm. The robot also gets a ultrasonic sensor for avoiding objects, as well as a camera for line-following duties. The camera also allows the robot to pick up blocks and identify their color, and it can then sort them into boxes. It’s all powered by a Raspberry Pi, running a bunch of Python code to make everything happen.

It’s a neat project that shows off just how capable a robot can be with some smart design choices and modern computing hardware on board. We’ve seen some other smart block sorters before, too. Continue reading “Hackaday Prize 2022: MasterPi Is A Capable Robot With Fancy Wheels” →

Hackaday Prize 2022: The Baffatari 2600 Adds Atari Compatibility To Retrocomputers

June 29, 2022 by Robin Kearey 16 Comments

Like today’s Intel-AMD duopoly, the market for home computer CPUs in the 1970s and ’80s was dominated by two players: Zilog with their Z80, and MOS Technology with their 6502 processor. But unlike today, even if two computers had the same CPU, it didn’t mean the two were software compatible: differences in memory layout, video interfaces, and storage media meant that software developed for an Atari 2600 wouldn’t run on an Apple I, despite the two sharing the same basic CPU architecture.

[Augusto Baffa]’s latest modern retrocomputer design, the Baffatari 2600, cleverly demonstrates that the difference between those two computers really is only skin-deep. The Baffatari is a plug-in board that adds Atari 2600 functionality to [Augusto]’s earlier Baffa-6502 system, which was designed to be Apple I-compatible. Since both the Apple and the Atari are powered by 6502 CPUs, only a few peripherals need to be swapped to change one into the other.

Sitting on the Baffatari board are two chips essential to the Atari 2600’s architecture: the 6532 RAM I/O Timer (RIOT) that contains the RAM and joystick interface, and the Television Interface Adapter (TIA) that handles the graphics and audio. These chips connect to the Baffa-6502’s system bus, enabling the main CPU to communicate with them and run Atari 2600 software titles. In the video embedded below, you can see several classic games running on the Baffa system.

The basic idea is similar to this RC2014 plug-in board that enables a Z80-based retrocomputer to run MSX and Colecovision titles. In fact, [Augusto] also built such a board for his earlier Z80 project.

Continue reading “Hackaday Prize 2022: The Baffatari 2600 Adds Atari Compatibility To Retrocomputers” →

Motherboard on the desk, with a CM4 plugged into it, and all kinds of wires connected to it for purposes of debugging

Hackaday Prize 2022: A CM4 Upgrade For Your Old IPad

June 27, 2022 by Arya Voronova 9 Comments

There’s no shortage of nicely built tablets out there, but unfortunately many of them are powered by what are by now severely outdated motherboards. Since manufacturers releasing replacement motherboards for their old hardware doesn’t look like its likely to be common practice anytime soon, the community will have to take things into their own hands. This is where [Evan]’s project comes in — designing a Raspberry Pi CM4-powered motherboard for the original iPad. It aims to have support for everything you’d expect: display, touchscreen, audio, WiFi, Bluetooth, and even the dock port. Plus it gives you way more computing power to make use of it all.

Testing part fitment with some cardboard CAD.

The original iPad got a lot of things right, a factor definitely contributing to its success back when it was released. [Evan]’s high-effort retrofit works with the iPad’s plentiful good parts, like its solid shell, tailored lithium-ion battery, eye-friendly LCD, and reliable capacitive touchscreen. You’d have to fit the new motherboard inside the space available after these parts all come together, and [Evan] has shaped his PCBs to do exactly that – with room for CM4, and the numerous ICs he’s added so as to leave no function un-implemented.

This project has been underway for over a year, and currently, there’s fourteen information-dense worklogs telling this retrofit’s story. Reverse-engineering the capacitive touchscreen and the LCD, making breakouts for all the custom connectors, integrating a custom audio codec, debugging device tree problems, unconventional ways to access QFN pins left unconnected on accident, and the extensive power management design journey. [Evan] has a lot to teach for anyone looking to bring their old tablet up to date!

The hardware files are open-source, paving the way for others to reuse parts for their own retrofits, and we absolutely would like to see more rebuilds like this one. This project is part of the Hack it Back round of the 2022 Hackaday Prize, and looks like a perfect fit to us. If you were looking for an excuse to start a similar project, now is the time.

Hackaday Prize 2022: Turning Big Box Trash Into Art Student Treasure

June 17, 2022 by Kristina Panos 11 Comments

How can the big box store mix the perfect shade of English Wedgwood right before your eyes? The answer is in highly-concentrated pigments that come in many different sizes up to a whopping five gallons. Now, just imagine the amount of watercolor, acrylic, or other types of paint that could be made by simply scraping the walls of an empty 5-gallon tub, which you know is just getting thrown away with all that usable pigment inside.

Not only is [technoplastique] making watercolors and other paints out of these pigments, but their true focus is on creating an easily-reproducible process for turning not just pigments into paint, but other things as well, like dried turmeric, charcoal, or any other feasible material.

The process will likely take the form of an open-source three-roller milling machine, which are commonly used in paint manufacture. Basically you have three rollers that process the pigment and binder, and the mixture is run through as many times as necessary. Although they are fairly simple machines in design, building them to work well requires adherence to precise technical specs.

We can’t wait to see what [technoplastique] comes up with to use for the stainless steel rollers. The rest of the plan involves a Raspberry Pi Pico, one DC motor per roller, a motor shield, and a power supply, but the rollers are pretty crucial. If you have any ideas other than steel rolling pins (the kitchen kind) or pipe couplings (which are too short, anyway), let us know in the comments!