Cobalt: apps and an SDK for Kobo e-readers

Cobalt is an open source application platform for Kobo e-readers, published at bandarlabs.github.io. It includes a launcher, a signed app store, a Rust SDK, and a runtime that keeps each app in its own unprivileged process. Install it once over USB, then install, update, and remove apps on the reader itself over WiFi. A reboot returns to the stock Kobo reader.

The app list covers reading and utilities: an arXiv preprint reader that handles sections, math, tables, and figures, an OPDS client for Project Gutenberg and Standard Ebooks, a Hacker News client with full comment threads, a Zotero browser, a terminal, Sudoku, and a tool that sends Morse code using the front light. Every package is verified before it opens, and an interrupted install leaves the working version in place.

Developers can start a Rust app, run it in the Cobalt simulator, test on a supported reader, and submit it to the Store without waiting for a platform release. Supported profiles are the Clara BW, Clara Colour, Clara HD, Elipsa 2E, Libra 2, and Libra Colour, each at specific firmware and kernel versions. Cobalt does not replace Kobo’s boot chain, and it is not affiliated with Rakuten Kobo.

See more at bandarlabs.github.io and code on GitHub.

from Adafruit Industries – Makers, hackers, artists, designers and engineers! https://ift.tt/OHWQuPJ
via IFTTT

Continue Reading

Hacking IKEA furniture

Wanting a workbench that had the practicality of a shop surface but the look of living room furniture, a maker documented turning IKEA Kallax shelving units into a pair of sturdy office workbenches. Custom furniture came in around 1,000 € per unit and kitchen cabinets did not offer good-looking sides or a workable layout, so the build started with two 2×2 Kallax units plus drawer and door inserts, MDF boards cut to size at the hardware store, screws, decorative foil, and rubber sheets. The top surface came from an old desk that had been sitting in the basement after failing to sell on eBay: a 160 cm by 80 cm desktop cut into two 80 cm by 60 cm pieces, with the cut edges hidden against the wall.

Assembly happened upside down, stacking the desktop, a 3 mm rubber sheet to damp vibration from a 3D printer and pen plotter, an MDF board, another rubber sheet, and then the Kallax, with a final MDF board screwed to the bottom of the shelving unit. Test drilling on an older unit showed that hollow IKEA panels will blow out if screws are overtightened, and paper templates plus drilling through matched pieces kept every hole aligned.

The two headaches were replacement shelf boards cut 355 mm wide instead of 335 mm, and shelf holes that turned out not to be symmetrical, solved on the second try by using inverted clamps to hold the shelf at the exact height and marking the holes directly instead of measuring. The finished benches feel dramatically more solid than a loose board resting on a cabinet, with only a slight lateral wobble when pushed around, and the whole project came in well under the cost of anything comparable off the shelf.

See more at greenlightning.eu.

Ed. note: around my house, we have several excellent IKEA hacks done by my spouse.

from Adafruit Industries – Makers, hackers, artists, designers and engineers! https://ift.tt/hvOkMmT
via IFTTT

Continue Reading

An NFC energy-harvesting PCB business card with a microcontroller

Wilson Harper set out to learn KiCad and ended up with a battery-free PCB business card that lights up 21 LEDs when tapped against a phone, powered entirely by harvested NFC energy.

The card pairs an NXP NTAG I2C Plus, which routes excess DC voltage out to external hardware, with a 3mm x 3mm ATtiny816 chosen for its QFN package and 17 GPIOs. Six of those pins drive 20 Charlieplexed LEDs plus a simple indicator LED.

The rectangular spiral antenna fills the whole card and was sized with STMicro’s inductance calculator to land near 2.75uH for resonance at 13.56MHz, generated by a KiCad Python script included in the repo since no existing plug-in could make the shape. Routing avoided a closed loop, and a ground plane, so eddy currents would not kill the antenna, and all traces are mirrored onto the back silkscreen alongside a block diagram and BOM.

Three exposed pads on the back at breadboard spacing allow programming over UPDI with a pogo pin clip, with a TVS diode protecting the MCU from wallet static. After a Pico-based programmer failed to produce any signal on the scope, an Adafruit UPDI Friend worked instantly. The main loop is bare-metal C at 1MHz to minimize flicker, the tag was written with NXP TagWriter, and thirty RoHS-compliant, credit-card-thin boards were ordered from JLCPCB. A second version is under consideration with different LED colors and maybe a button or two for arcade-style games.

See more at wilsonharper.net and content on GitHub.

from Adafruit Industries – Makers, hackers, artists, designers and engineers! https://ift.tt/RHZn4b0
via IFTTT

Continue Reading

Ben Eater’s Digital Clock

Bust out the breadboards because Ben Eater is showing you how to build a really cool digital clock.

from Adafruit Industries – Makers, hackers, artists, designers and engineers! https://ift.tt/Xn7kQSR
via IFTTT

Continue Reading

Tour the Fall Sky with the Amateur Astronomers Association

 

The AAA offers classes, including this free virtual class scheduled for Tuesday 9/22 at 7pm:

We’ll learn the constellations seen in the northeast of the U.S. roughly between 8 PM and 1 AM. That part of the sky contains 10-12 of the 44 Northern constellations. We’ll review their outlines, allegorical representations, myths, history, key stars, and unique deep sky objects located within them.

Our instructor is Lydia Maria Petrosino, AAA resource on astronomy history and sky myths, and former presenter at NYC’s Hayden Planetarium.

If you can’t make this class check out Gothamist’s Septmber star guide or learn how to let NASA do all the work filling your digital PyPortal picture frame with images from space!

from Adafruit Industries – Makers, hackers, artists, designers and engineers! https://ift.tt/5ob1az8
via IFTTT

Continue Reading

An MIT graduate student helped a team of young scientists test their experiment at CERN

Last spring, MIT physics graduate student Manu Srivastava got an email from six high school students in India he’d never met. They were entering Beamline for Schools — an international competition that lets secondary students run experiments on particle accelerator beams — and needed a mentor. He usually declines such requests, which typically arrive through companies charging families for access to scientists. This one came straight from the students, so he said yes. Team attoPION was one of five teams chosen from a record 712 entries across 89 countries.

They settled on measuring pion charge exchange: a positive pion hits a neutron and produces a neutral pion and a proton. It matters to DUNE, the Deep Underground Neutrino Experiment, because pion interactions feed into estimates of a neutrino’s flavor and energy. DUNE co-spokesperson Dave Newbold calls it real experimental particle physics, not a classroom demonstration, and rates it far above anything he considered in high school.

At CERN the team spent two weeks on detectors and data acquisition. Preparation revealed the reaction is extremely rare, forcing hard thinking about detecting it at all with just 12 days of beam time. Support scientist Berare Göktürk was candid that a DUNE-useful result would be ambitious — her priority is that the students understand the journey of a scientist. Srivastava, a theorist who grew up in India, didn’t know what CERN was in high school. These students, he says, are just that good.

Read the full story – MIT News. Competition results – CERN.

from Adafruit Industries – Makers, hackers, artists, designers and engineers! https://ift.tt/I5YzFcx
via IFTTT

Continue Reading

Hand-Crank Flashlight

You can never be too prepared for a situation that requires light.CrazyScience shared how they built a hand-crank flashlight.

For this project, I took a small SG90 micro servo, modified it for continuous rotation, and turned it into the heart of a compact hand-crank flashlight.

You can check out the details of their build on instructables.

from Adafruit Industries – Makers, hackers, artists, designers and engineers! https://ift.tt/AWaPZLo
via IFTTT

Continue Reading