Portable Pi Teensy Thumboard

Even on the go, there is no substitute for a physical keyboard with buttons that move and click. Sure, you could solder a bunch of tactile switches to some perfboard, but how about going all out and making something robust as [Anthony DiGirolamo] did for his Teensy Thumboard. Everything is insertion-mount so it is an approachable project for anyone who knows the dangerous end of a soldering iron, and that also makes it easy to hack on.

Each pin of the Teensy has an adjacent empty hole tied to it for easy access, and the serial data pins are exposed at the top of the board. All the holes use standard 0.1″ (2.54mm) spacing. The I/O points used by the keyboard are labeled, and the rest of them can use the space under the controller where proto-board style holes add some extra space for an IMU or whatever sensors suit your slant.

Most impressive is the shell, which is freely available on Thingiverse, where you can also find a bill of materials with links to everything you will need in case you don’t have drawers full of those tactile switches.

If this looks familiar, you have probably seen the PocketCHIP, and it is no secret that this project is an homage to that versatile pocket computer. We appreciate this kind of love for PocketCHIP, especially since they are now a limited commodity.

The Smaller, More Powerful Raspberry Pi 3 Model A+

It’s that time of year again, and the Raspberry Pi Foundation has some new hardware for you. This time, it’s an improved version of the Raspberry Pi Model A, bringing it the speed and power of its bigger brother, the Raspberry Pi Model 3 B+.

The Raspberry Pi Model A is the weird middle child of the Raspberry Pi lineup, or maybe it’s the Goldilocks choice. It’s not as powerful and doesn’t have the USB ports or Ethernet jack found in the latest revision of the family, the Raspberry Pi Model 3 B+, and it’s not as small or as cheap as the Raspberry Pi Zero W. If you’re running a Pi as just something that takes in power and spits out data on the GPIO pins, the Model A might be all you need.

The full specs include:

  • Broadcom BCM2837B0 Cortex A-53 running at 1.4GHz
  • 512 MB of LPDDR2 SRAM
  • 2.4 GHz and 5 GHz 802.11 b/g/n/ac wireless LAN, Bluetooth 4.2/BLE
  • Full size HDMI
  • MIPI DSI display port / CSI camera port
  • Stereo Output and composite video port

In short, we’re looking at a cut-down version of the Raspberry Pi Model 3 B+ released earlier this year, without an Ethernet port and only one USB port. The wireless chipset is hidden under a lovely embossed can, and until we get our hands on this new model and a pair of pliers, we’re assuming this is a CYW43455, the Cypress chipset found in the Pi 3 B+.

The price of the Raspberry Pi 3 Model A+ will be $25 USD, with availability soon at the usual retailers. Since there’s no such thing as a Pi Zero 3 yet, if you’re looking for a powerful Linux computer, with wireless, in a small form factor, you’re not going to do much better than this little guy. You could of course desolder a Pi 3 B+, but for now this is the smallest, most powerful single board computer with good software support.

GTA: San Andreas Radio Earns Six-Star Wanted Level

[Raphaël Yancey] wanted to be able to jam to Bounce FM and Radio:X all the time, without having to steal a car or a street sweeper in San Andreas. As people who like to put on the sad piano building music from The Sims and write Hackaday posts, we can totally relate.

But this isn’t just another one of those jam-a-Pi-into-a-vintage-radio-and-call-it-a-sandwich projects (not that there’s anything wrong with those). This thing acts like a real radio. All the stations play continuously whether you’re tuned in or not, and they bleed into each other as you go up and down the dial.

After much trial and error, [Raphaël] found a Python mixer that would work, but it was no longer maintained. He forked it, squashed a bug or two, and wrote a module for KY040 rotary encoders to make them play nice with the Pi. The snake charming doesn’t stop there: the rock star of this project is [Raphaël]’s virtual radio software, which handles the audio blending as he tunes between stations. A step-by-step tutorial is coming soon, so watch [Raphaël]’s site for updates. Tune past the break to give it a listen.

Adventures in Raspi radio-ing don’t have to be one-way. Here’s how you can turn one into an AM/FM+ transmitter using a DVB-T dongle and SDR.

Continue reading “GTA: San Andreas Radio Earns Six-Star Wanted Level”

A Cartoon-ifying Camera for Instant Absurdism

We take photographs as a way to freeze moments in time and to capture the details that get blurred by our unreliable memories. There is little room for interpretation, and this is kind of the whole point.

[Dan Macnish]’s latest project, Draw This, turns reality into absurdity. It’s a Raspberry Pi-based instant camera that trades whatever passed in front of the lens for a cartoon version of same. Draw This uses neural networks to ID the objects in the frame, and then draws upon thousands of images from Google’s Quick, Draw! dataset to provide a loose interpretation via thermal printer. Seems to us like the perfect camera to take to DEFCON (or any other part of Las Vegas).

If you have a Raspi3, a v2 camera, and a thermal printer, you can make your own crowd-sourced, cartoonified memories using the code in [Dan]’s repo. Still into recording reality? You can use Pi cameras to see in the dark or even explore a body of water.

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.

Continue reading “Automatic MtG Card Sorter Separates Rags from Riches”

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!