Automatic MtG Card Sorter Separates Rags from Riches

Like many of us, [Michael Portera] was an avid trading card collector as a kid. Also like many of us, life got in the way, and the collections sat ignored in boxes until our mothers threatened to get rid of them (or skipped the threat altogether and sold them at a garage sale for next to nothing).

[Michael] was recently reunited with his collection of Magic cards, which vary in value as much as baseball or any other kind of collectible card. Now that his Friday nights are otherwise occupied, he decided to sell them off. But first, he had to know how much they’re worth.

Manually sorting and pricing hundreds of cards would take longer than he’d like, so he built a sorter to automate the process. It takes a stack of MtG cards and uses servos and little tires to move them, one by one, into position. A short Python script runs the servos, tells a Raspi 3 camera take a picture of each one, and uploads it to Amazon AWS. Once the pictures are there, [Michael] uses a second script to grab the card title text from the picture and fetch the value through TCGPlayer’s pricing API.

This machine probably isn’t for purists or people with a bunch of originals and re-issues of the same card. We probably should have mentioned that he took out all the Black Lotuses and other obviously valuable cards first. Someone still has to assess the condition of each card, but at two seconds per card, it’s quite the time twister saver. Time Walk past the break to see it in action.

Tired of using dice or scratch paper for your life counter? Summon some Nixie tubes and make a cooler one.

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Making Custom Silicon For The Latest Raspberry Pi

The latest Raspberry Pi, the Pi 3 Model B+, is the most recent iteration of hardware from the Raspberry Pi Foundation. No, it doesn’t have eMMC, it doesn’t have support for cellular connectivity, it doesn’t have USB 3.0, it doesn’t have SATA, it doesn’t have PCIe, and it doesn’t have any of the other unrealistic expectations for a thirty-five dollar computer. That doesn’t mean there wasn’t a lot of engineering that went into this new version of the Pi; on the contrary — the latest Pi is filled with custom silicon, new technologies, and it even has a neat embossed RF shield.

On the Raspberry Pi blog, [James Adams] went over the work that went into what is probably the most significant part of the new Raspberry Pi. It has new, custom silicon in the power supply. This is a chip that was designed for the Raspberry Pi, and it’s a great lesson on what you can do when you know you’ll be making millions of a thing.

The first few generations of the Raspberry Pi, from the original Model B to the Zero, used on-chip power supplies. This is what you would expect when the RAM is soldered directly to the CPU. With the introduction of the Raspberry Pi 2, the RAM was decoupled from the CPU, and that meant providing more power for more cores, and the rails required for LPDDR2 memory. The Pi 2 required voltages of 5V, 3.3V, 1.8V, and 1.2V, and the sequencing to bring them all up in order. This is the job for a power management IC (PMIC), but surprisingly all the PMICs available were more expensive than the Pi 2’s discrete solution.

The MXL7704, with four switching power supplies. The four symmetric gray and brown bits are inductors.

However, where there are semiconductor companies, there’s a possibility of having a custom chip made. [James] talked to [Peter Coyle] of Exar in 2015 (Exar was then bought by MaxLinear last year) about building a custom chip to supply all the voltages found in the Raspberry Pi. The result was the MXL7704, delivered just in time for the production of the Raspberry Pi 3B+.

The new chip takes the 5V in from the USB port and converts that to two 3.3V rails, 1.8V and 1.2V for the LPDDR2 memory, 1.2V nominal for the CPU, which can be raised and lowered via I2C. This is an impressive bit of engineering, and as any hardware designer knows, getting the power right is the first step to a successful product.

With the new MXL7704 chip found in the Raspberry Pi 3B+, the Pi ecosystem now has a simple and cheap chip for all their future revisions. It might not be SATA or PCIe or eMMC or a kitchen sink, but this is the kind of engineering that gives you a successful product rather than a single board computer that will be quickly forgotten.

Circuit-Sword Delivers Retro Justice

You can’t search for “retro gaming” without hitting a plethora of single board computers attached to all manner of controls, batteries, etc. Often these projects have an emphasis on functionality above all else but [Kite]’s Circuit-Sword is different. The Circuit-Sword is the heart of a RaspberryPi-based retro gaming machine with an enviable level of fit and finish.

Fundamentally the Circuit-Sword is a single board computer built around a Raspberry Pi Compute Module 3. We don’t see many projects which use a Compute Module instead of the full Pi, but here it is a perfect choice allowing [Kite] to useful peripherals without carrying the baggage of those that don’t make sense for a portable handheld (we’re looking at you, Ethernet). The Circuit-Sword adds USB-C to quickly charge an onboard LiPo (rates up to 1.5A available) and the appropriate headers to connect a specific LCD. The Compute Module omits wireless connectivity so [Kite] added an SDIO WiFi/Bluetooth module. And if you look closely, you may notice an external ATMega mediating a familiar looking set of button and switches.

Optional Drill Holes

We think those buttons and switches are the most interesting thing going on here, because the whole board is designed to fit into an original GameBoy enclosure. It turns out replacement enclosures are available from China in surprising variety (try searching for “gameboy housing”) as are a variety of parts to facilitate the installation of different screen options and more. One layer deeper in the wiki there are instructions for case mods you may want to perform to make everything work optimally. The number of possible options the user can mod-in are wide. Extra X/Y buttons? Shoulder buttons on the back? Play Station Portable-style slide joysticks? All detailed. For even more examples, try searching the SudoMod forums. For example, here’s a very visual build log by user [DarrylUK].

The case mod instructions are worth a glance even if you have no intent to build a device. There are some clever techniques to facilitate careful alignment of buttons and accurate hole drilling. Predicting their buyers might want a variety of options, [Kite] added reference drill holes in the PCB for the builder to re-drill for mounting buttons or joysticks. To facilitate adding status LEDs externally there is a tiny PCB jig included. There are even instructions for adding a faux game cartridge for the complete look.

If you want to buy one (we certainly do!) [Kite] does group buys periodically. Check out the wiki for links to the right interest form.

Thanks [Speednut Dave] for the tip!

Yellow Robot Wheels Rolling Out

Small wheeled robots are great for exploring robotics and it’s easier than ever to get started, thanks to growing availability and affordability of basic components. One such component is a small motorized wheel assembly commonly shown when searching for “robot wheel”: a small DC motor mounted in a gearbox to drive a single plastic wheel (inevitably yellow) on which a thin rubber tire has been mounted for traction. Many projects have employed these little motor + gearbox + wheel modules, such as these three entries for 2018 Hackaday Prize:

BoxBotics takes the idea of an affordable entry point and runs with it: build robot chassis for these wheels out of cardboard boxes. (Maybe even the exact box that shipped the yellow wheels.) Cardboard is cheap and easy to work with, making cardboard projects approachable to any creative mind. There will be an audience for something like a Nintendo Labo for robotics, and maybe BoxBotics will grow into that offering.

Cing also intends to make a friendly entry point for robotics and they offer a different chassis solution. Instead of cardboard, they use a circuit board. The yellow gearbox is mounted directly to the main circuit board making it into the physical spine, along with its copper traces serving as the spinal cord of the robot. While less amenable to mechanical creativity than BoxBotics, Cing’s swappable modules might be a better fit for those interested in exploring electronics.

ROS Starter Robot caters to those who wish to go far beyond simple “make it move” level of robot intelligence. It aims to lower the barrier to enter the world of ROS (robot operating system) which has historically been the domain of very capable (but also very expensive) research-oriented robots. This project could become the bridge for aspiring roboticists who wish to grow beyond hobbyist level software but can’t justify the cost typical of research level hardware.

All three of these projects take the same simple motorized wheel and build very different ideas on top of them. This is exactly the diversity of ideas we want to motivate with the Hackaday Prize and we hope to see great progress on all prize contestants in the month ahead.

Raspberry Pi Gets Faster CPU and Better Networking in the New Model 3 B+

While the Raspberry Pi’s birthday (and the traditional release date for the newest and best Pi) was a few weeks ago, Pi Day is a fitting enough date for the introduction of the best Pi to date. The Raspberry Pi 3 Model B+ is the latest from the Raspberry Pi foundation. It’s faster, it has better networking, and most interestingly, the Pi 3 Model B+ comes with modular compliance certification, allowing anyone to put the Pi into a product with vastly reduced compliance testing.

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The Sensor Array That Grew Into a Robot Cat

Human brains evolved to pay extra attention to anything that resembles a face. (Scientific term: “facial pareidolia”) [Rongzhong Li] built a robot sensor array with multiple emitters and receivers augmenting a Raspberry Pi camera in the center. When he looked at his sensor array, he saw the face of a cat looking back at him. This started his years-long Petoi OpenCat project to build a feline-inspired body to go with the face.

While the name of the project signals [Rhongzhong]’s eventual intention, he has yet to release project details to the open-source community. But by reading his project page and scrutinizing his YouTube videos (a recent one is embedded below) we can decipher some details. Motion comes via hobby remote-control servos orchestrated by an Arduino. Higher-level functions such as awareness of environment and Alexa integration are handled by a Raspberry Pi 3.

The secret (for now) sauce are the mechanical parts that tie them all together. From impact-absorption spring integrated into the upper leg to how its wrists/ankles articulate. [Rongzhong] believes the current iteration is far too difficult to build and he wants to simplify construction before release. And while we don’t have much information on the software, the sensor array that started it all implies some level of sensor fusion capabilities.

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DIY Text-to-Speech with Raspberry Pi

We can almost count on our eyesight to fail with age, maybe even past the point of correction. It’s a pretty big flaw if you ask us. So, how can a person with aging eyes hope to continue reading the printed word?

There are plenty of commercial document readers available that convert text to speech, but they’re expensive. Most require a smart phone and/or an internet connection. That might not be as big of an issue for future generations of failing eyes, but we’re not there yet. In the meantime, we have small, cheap computers and plenty of open source software to turn them into document readers.

[rgrokett] built a RaspPi text reader to help an aging parent maintain their independence. In the process, he made a good soup-to-nuts guide to building one. It couldn’t be easier to use—just place the document under the camera and push the button. A Python script makes the Pi take a picture of the text. Then it uses Tesseract OCR to convert the image to plain text, and runs the text through a speech synthesis engine which reads it aloud. The reader is on as long as it’s plugged in, so it’s ready to work at the push of a button. We can probably all appreciate such a low-hassle design. Be sure to check out the demo after the break.

If you wanted to use this to read books, you’d still have to turn the pages yourself. Here’s a BrickPi reader that solves that one.

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