This Debug Connector Brings Your Issues To The Edge

Given an unknown PCBA with an ARM processor, odds are good that it will have either the standard 10 pin 0.05″ or 20 pin 0.1″ debug connector. This uncommon commonality is a boon for an exploring hacker, but when designing a board such headers require board space in the design and more components to be installed to plug in. The literally-named Debug Edge standard is a new libre attempt to remedy this inconvenience.

The name “Debug Edge” says it all. It’s a debug, edge connector. A connector for the edge of a PCBA to break out debug signals. Card edge connectors are nothing new but they typically either slot one PCBA perpendicularly into another (as in a PCI card) or hold them in parallel (as in a mini PCIe card or an m.2 SSD). The DebugEdge connector is more like a PCBA butt splice.

It makes use of a specific family of AVX open ended card edge connectors designed to splice together long rectangular PCBAs used for lighting end to end. These are available in single quantities starting as low as $0.85 (part number for the design shown here is 009159010061916). The vision of the DebugEdge standard is that this connector is exposed along the edge of the target device, then “spliced” into the debug connector for target power and debug.

Right now the DebugEdge exists primarily as a standard, a set of KiCAD footprints, and prototype adapter boards on OSHPark (debugger side, target side). A device making use of it would integrate the target side and the developer would use the debugger side to connect. The standard specifies 4, 6, 8, and 10 pin varieties (mapping to sizes of available connector, the ‘010’ in the number above specifies pincount) offering increasing levels of connectivity up to a complete 1:1 mapping of the standard 10 pin ARM connector. Keep in mind the connectors are double sided, so the 4 pin version is a miniscule 4mm x 4.5mm! We’re excited to see that worm its way into a tiny project or two.

We’ve seen plenty of part-free debug and programming connectors before. Have a favorite? Let us know in the comments!

Building An Open Hardware EBook Reader

On the whole, hackers aren’t overly fond of other people telling them what they can and cannot do with the hardware or software they’ve purchased. Unfortunately, it’s becoming more and more difficult to avoid DRM and other Draconian rules and limitations as time goes on. Digital “eBooks” and the devices that are used to view them are often the subject of such scrutiny, which is why [Joey Castillo] has made it his mission to develop a open hardware eReader that truly belongs to the user.

[Joey] has been working on what he calls the “The Open Book Project” for a few months now, and he’s just recently announced that the first reader has been successfully assembled and powered up. As is usually the case, a few hardware issues were identified with this initial prototype. But it sounds like the device was largely functional, and only a few relatively minor tweaks to the board layout and components should be necessary before the hardware is ready for the masses.

An earlier prototype, using the Adafruit Feather

If you’re feeling a bit of déjà vu seeing this, don’t worry. The Open Book Project has taken a somewhat circuitous path to get to this first prototype, and [Joey] had previously developed and built the “eBook Feather Wing”. While they look very similar, that earlier incarnation required an Adafruit Feather to operate and was used to help refine the firmware and design concepts that would go into the final hardware.

The Open Book is powered by a ATSAMD51N19A processor with a GD25Q16 2MB flash chip to hold the CircuitPython code, and a microSD slot to store the actual book files. It also features support for audio output via a standard 3.5 mm headset jack, an RGB status LED, and expansion ports that tap into the I2C interface for adding whatever other hardware you can dream up.

One of the most interesting aspects of this Creative Commons licensed reader is the extensive self documentation [Joey] has included on the silkscreen. Every major component on the back of the PCB has a small description of its purpose and in some cases even a breakdown of the pin assignments. The idea being that it not only makes the device easier to assemble and debug, but that it can also explain to the curious user what everything on the board does and why it’s necessary. It’s a concept that makes perfect sense given the goals of the Open Book Project, and something that we frankly would love to see more of.

[Marc Juul] presented his work on a FOSS operating system for older-model Kindles at HOPE XII as a way to avoid Orwellian monitoring of the user’s reading habits, so it’s interesting to see somebody take this idea to the next level with completely libre reader hardware. Unfortunately none of this addresses the limited availability of DRM-free eBooks, but one step at a time.

Glia Is Making Open Medical Devices, And You Can Help

The Glia project aims to create a suite of free and open-source medical equipment that can be assembled cheaply and easily when and where it’s needed. Even essential tools like stethoscopes and tourniquets can be difficult to acquire in certain parts of the world, especially during times of war or civil unrest. But armed with a 3D printer and the team’s open-source designs, an ad-hoc factory can start producing these lifesaving tools anywhere on the planet.

Glia member [Tarek Loubani] has recently written a blog post discussing the team’s latest release: an otoscope that can be built for as little as $5. Even if you don’t recognize the name, you’ve almost certainly seen one of them in use. The otoscope is used to look inside the ear and can be invaluable in diagnosing illnesses, especially in children. Unfortunately, while this iconic piece of equipment is quite simple on a technical level, professional-quality versions can cost hundreds of dollars.

Now to be fair, you’ll need quite a bit more than just the 3D printed parts to assemble the device. The final product requires some electrical components such as a battery holder, rocker switch, and LED. It also requires a custom lens, though the Glia team has thought ahead here and provided the files for printable jigs that will allow you to cut a larger lens down to the size required by their otoscope. In a situation where you might have to improvise with what you have, that’s a very clever design element.

So far the team is very happy with how the otoscope performs, but they’ve run into a bit of a logistical snag. It turns out that early work on the project was done in the web-based TinkerCAD, which isn’t quite in line with the team’s goals of keeping everything free and open. They’d like some assistance in recreating the STLs in FreeCAD or OpenSCAD so they’re easier to modify down the road. So if you’re a FOSS CAD master and want to earn some positive karma, head over to the GitHub page for the project and put those skills to use.

We’ve previously covered Glia’s work with 3D printed tourniquets to treat gunshot wounds, a project that led to [Tarek] himself being shot by a sniper while attempting to field test the design in Gaza. If that’s not commitment to the principles of open-source hardware, we don’t know what is.

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