Giant Analog CO2 Meter Sweeps Away Doubt

Most of us are aware that trees turn CO₂ into oxygen, but we’d venture to guess that many people’s knowledge of this gas ends there. Is it feast or famine out there for the trees? Who can say? We admire [rabbitcreek]’s commitment to citizen science because he’s so focused on making it easy for people to understand their environment. His latest offering, a giant analog CO₂ meter, might be our favorite so far.

The brains of the operation is an Adafruit Feather Adalogger. It reads the CO₂ sensor that’s mounted close to the business end of the nautilus, and becomes the quill that writes the CO₂ value to a FeatherWing e-ink screen. For the giant needle, this lovely meter uses one of those fiberglass poles you mark your driveway with so you can find it under a blanket of snow. The needle is counter-balanced with washers encased in printed plastic.

As you can see in the GIF, there’s a decent delay between the CO₂ blast and the needle response — we like to imagine the CO₂ spiraling slowly through the nautilus like a heavy, ill wind on its way to gravely move the needle.

Want a way to monitor air quality that’s a bit more discreet? Slip this portable meter into your pocket.

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.

Handheld LoRa Joystick For Long-Range Bots

Wanting a simple tool to aid in the development of LoRa controlled robotic projects, [Jay Doscher] put together this very slick one-handed controller based on the 900 MHz Adafruit Feather M0. With a single trigger and a miniature analog joystick it’s a fairly simple input device, but should be just enough to test basic functionality of whatever moving gadget you might find yourself working on.

Wiring for this project is about as simple as you’d expect, with the trigger and joystick hanging off the Feather’s digital ports. The CircuitPython code is also very straightforward, though [Jay] says in the future he might expand on this a bit to support LoRaWAN. The controller was designed as a barebones diagnostic tool, but the hardware and software in its current form offers an excellent opportunity to layer additional functionality on a known good base.

Everything is held inside a very well designed 3D printed enclosure which [Jay] ran off on his ELEGOO Mars, one of the new breed of low-cost resin 3D printers. The machine might be pretty cheap, but the results speak for themselves. While resin printing certainly has its downsides, it’s hard not to be impressed by the finish quality of this enclosure.

While LoRa is generally used for transmitting small bits of information over long distances, such as from remote sensors, this isn’t the first time we’ve seen it used for direct control of a moving object. If you’re not up to speed on LoRa, check out this excellent talk from [Reinier van der Lee] that goes over the basics of the technology and how he used it to build a community sensor network.

Temperature Logging On The Last Frontier

In Alaska, the impact of climate change is easy to see. Already the melting permafrost is shifting foundations and rocking roads. Hotter summers are also turning food caches from refrigerators into ovens.

A permanent food cache. Via Wikipedia

[rabbitcreek]’s friend builds food caches with kids as part of a program to teach them traditional native activities. Food caches are usually inside buried boxes or small cabins raised on poles. Both are designed to keep hangry bears out. As you might expect, monitoring the temperature at these remote sites is crucial, so the food doesn’t spoil. His friend wanted a set-and-forget temperature monitoring system that could collect data for eight months over the winter.

The Alaska Datalogger carried a pretty serious list of requirements. It has to be waterproof, especially as ice and snow turn to water. Ideally, it should sip power and have a long battery life anyway. Most importantly, it has to be cheap and relatively easy for kids to build.

This awesome little data spaceship is designed around an O-ring used in domestic water purifiers. The greased up O-ring fits between two 3D printed enclosure halves that are shut tight with nylon bolts. Two waterproof temperature probes extend from the case—one inside the cache and the other outside in the elements. It’s built around an Adafruit Feather Adalogger and powered by an 18650 cell. The data is collected by visiting the site and pulling the SD card to extract the text file. There’s really no other way because the sites are far out of cell coverage. Or is there?

Though it probably wouldn’t survive the last frontier, this self-sufficient weather station is a simple solution for sunnier situations.

Broken HP-48 Calculator Reborn As Bluetooth Keyboard

Considering their hardware specification, graphing calculators surely feel like an anachronism in 2019. There are plenty of apps and other software available for that nowadays, and despite all preaching by our teachers, we actually do carry calculators with us every day. On the other hand, never underestimate the power of muscle memory when using physical knobs and buttons instead of touch screen or mouse input. [epostkastl] combined the best of both worlds and turned his broken HP-48 into a Bluetooth LE keyboard to get the real feel with its emulated counterpart.

Initially implemented as USB device, [epostkastl] opted for a wireless version this time, and connected an nRF52 based Adafruit Feather board to the HP-48’s conveniently exposed button matrix pins. For the software emulation side, he uses the Emu48, an open source HP calculator emulator for Windows and Android. The great thing about Emu84 is that it supports fully customizable mappings of regular keyboard events to the emulated buttons, so you can easily map, say, the cosine button to the [C] key. The rest is straight forward: scanning the button matrix detects button presses, maps them to a key event, and sends it as a BLE HID event to the receiving side running Emu84.

As this turns [epostkastl]’s HP-48 essentially into a regular wireless keyboard in a compact package — albeit with a layout that outshines every QWERTY vs Dvorak debate. It can of course also find alternative use cases, for examples as media center remote control, or a shortcut keyboard. After all, we’ve seen the latter one built as stomp boxes and from finger training devices before, so why not a calculator?

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The Bluetooth LCD Sniffer You Didn’t Know You Needed

At one time or another, we’ve all suffered through working with a piece of equipment that didn’t feature a way to export its data to another device. Whether it was just too old to offer such niceties, or the manufacturer locked the capability behind some upgrade, the pain of staring at digits ticking over on a glowing LCD display and wishing there was a practical way to scrape what our eyes were seeing is well known to hackers.

That was precisely the inspiration for DoMSnif, the dot matrix LCD sniffer that [Blecky] has been working on. Originally the project started as a way to record the temperature of his BRTRO-420 reflow oven, but realizing that such a device could have widespread appeal to other hardware hackers, he’s rightfully decided to enter it into the 2019 Hackaday Prize. If perfected, it could be an excellent way to bolt data capture capabilities to your older devices.

The first phase of this project was figuring out how to capture and parse the signals going into the device’s KS0108 LCD. Getting the data was certainly easy enough, he just had to hook a logic analyzer up between the display and the main board of the device. Of course, figuring out what it all means is a different story.

After running the oven for a bit with the analyzer recording, [Blecky] had more than enough data to get started on decoding it. Luckily, the layout of this fairly common 128×64 pixel display is well documented and easy enough to understand. With a little work, he was able to create a tool that would import the captured data and display it on a virtual LCD.

Unfortunately, the Bluetooth part is where things get tricky. Ultimately, [Blecky] wants to ditch the logic analyzer and use a Adafruit Feather nRF52 Bluefruit to capture the signals going to the LCD and pipe them to a waiting device over Bluetooth. But his testing has found that the nRF52’s radio is simply too slow. The display is receiving data every 14us, but it takes the radio at least 50us to send a packet.

[Blecky] is looking at ways around this problem, and we’re confident he’ll crack it. The solution could be in buffering and compressing the data before sending it out, though you’d lose the ability to monitor the display in real-time. Even if he has to abandon the Bluetooth aspect entirely and make the device wired, we still think there would be a market for an easy to use hardware and software solution for scraping LCD data.

The Feather “FAUXBERRY” Is Now A Real Thing

Last month we featured an interesting project from Hackaday.io that was essentially trying to recreate the iconic Blackberry form factor for use with Adafruit’s line of Feather development boards. This would let you drop in modules for everything from LTE to packet radio, opening up a nearly limitless possibilities for handheld hacking. The only problem was, it didn’t actually exist yet.

But recently creator [arturo182] wrote in to tell us that not only had all the parts arrived, but that he’d completed assembly of the first prototype. He even put together a video about the current status of the device, which you can see after the break. The short version is: it works, and it looks fantastic.

For those who might not have seen this project the first time around, the front features a 2.6 inch 320×240 touch screen display, four general purpose buttons, a RGB NeoPixel LED for visual status display, a five way joystick, and what’s arguably the star of the show, a QWERTY keyboard originally designed for the Blackberry Q10. Around the back it has an SD card slot, a socket for the Feather module of your choice, and some handy GPIO expansion pads you can attach your own hardware onto.

[arturo182] says he’s looking at a couple cosmetic changes, but on the whole, everything works and he considers the PCB essentially done. He’ll soon be sending out a handful of test units to individuals who’ve expressed interest in helping him develop the project and then…well, he’s not really sure what’s going to happen then. Some kind of commercial release seems like the logical conclusion given the interest he’s already seen in the project, but he hasn’t quite worked out whether that will be a kit or as assembled devices.

Until then, anyone who’s looking for a pocket sized device that will let them bang out some Python with a physical keyboard will have to stick with their TI-83s.

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