Day: June 3, 2021

Lamp Sheds Light On Air Quality

June 3, 2021 by 4 Comments

It can be difficult to appreciate when the air quality is decent and when it’s poor, unless conditions are so bad that you can literally see the smog hanging in the air. Rather than try to digest a bunch of air quality numbers, [guillaume_slizewicz] built Canari — a lovely lamp that sheds light on the air pollution problem by taking local air quality data and turning it into light patterns.

Canari is of course named after the brave birds that once alerted miners to dangerous air conditions before they were forced to switch to carbon monoxide sensors. This bird has a Raspberry Pi Zero W that gets air quality data from a public API and controls the lights with a PWM bonnet based on the concentration of particulates in the air. The more particulates, the dimmer the LEDs are, and the faster they fade in and out.

The main piece of data that Canari grabs is the amount of particulate matter, and the display can switch between representing the level of PM2.5 (particulate matter with diameter less than 2.5 micrometers)  in the air and PM10. Check out the demo and setup video after the break.

More of a numbers person? All you really need is a microcontroller, an air quality sensor, and a display.

Continue reading “Lamp Sheds Light On Air Quality” →

Gdbdiff: Diff-ing A Real RP2040 MCU Against An Emulated MCU

June 3, 2021 by 15 Comments

What to do when developing an RP2040 emulator but validating the emulator instruction by instruction is a slow and tedious process? Why, automatically compare it against the real hardware if you’re [Uri Shaked], of course. This is the purpose of gdbdiff. This project uses the GDB remote serial protocol via OpenOCD to run test firmware step by step.

During a livestream (video linked via the above link), this allowed [Uri] to find a number of instruction bugs in the emulator this way. These issues involved issues such as incorrect flags in the APSR register and an edge case in the LSRS register. This gdbdiff livestream is part of an entire series of live-coding sessions during which [Uri] writes an RP2040 emulator from scratch.

We applaud [Uri] for creative thinking here, and assume that this way the livestream was probably more entertaining to watch than when doing instruction-level debugging purely by hand :)

Radio Build Goes Outside The Box

June 3, 2021 by 4 Comments

It’s easy to get caught up in a build and forget that the final version usually needs some sort of enclosure, especially things with sensitive electronics in them. The [Director of Legal Evil] at the LVL1 Louisville Hackerspace notes as much in his recent radio build. It seems as though the case was indeed an afterthought, but rather than throwing it in a nondescript black project enclosure it was decided to turn the idea of a project enclosure itself inside-out.

The radio build is based on an SI4732 radio receiver which is a fairly common radio module and is easily adaptable. It needs a microcontroller to run though, so a Maple STM32 platform was chosen to do all of the heavy lifting. The build includes a screen, some custom analog controls, and a small class D audio amplifier, but this is the point it begins to earn its name: the Chaos Radio. While playing around with the project design in CAD, a normal design seemed too bland so one was chosen which makes the radio look like the parts are exploding outward from what would have been a more traditional-style enclosure.

While the project includes a functioning radio receiver, we have to complement the creator for the interesting display style for this particular set of hardware. It can get boring designing the same project enclosures time after time, so anything to shake things up is often welcomed especially when it puts all of the radio components on display like this. In fact, it’s reminiscent of some of [Dmitry]’s projects, an artist known for deconstructing various common household appliances like this CD Player.

Thanks to [Jose] for the tip!

Air Extractor Automatically Gives AC A Boost

June 3, 2021 by 39 Comments

Portable air conditioning units are a great way to cool off a space during the hot summer months, but they require some place to blow the heat they’ve removed from your room. [VincentMakes] got a portable AC unit for his home, but he found that the place he wanted to put it was too far from the only window he could use to dump the hot air. Having too long of a duct on the hot air exhaust increases the back pressure on the fan which could cause it to prematurely fail, so [Vincent] used an extractor fan to automatically give is AC unit’s exhaust a boost on its way to the window.

Because his AC can operate at low, medium, and high speeds, he chose an extractor fan that also supported multiple speeds and took care to match the airflow of the AC and extractor fan to avoid putting too much strain on either fan. He designed a system to automatically set the speed of the boosting fan to match that of the AC using a Hall effect current sensor to measure the AC unit’s power draw and an Arduino Nano for control. A custom PCB interfaces the Nano to the Hall Sensor and control relays, and we have to applaud [Vincent] for keeping the +5V DC and 230V AC far, far away from each other. In addition to this fine electronics work, [Vincent] also built an enclosure for the fan controller that allows the fan to be mounted on top at an angle, which helps avoid having hard bends in the exhaust duct.

If this has you thinking about smart air conditioners to keep cool this summer, check out this ESP8266-powered smart AC system, or this Raspberry Pi-based system that controls both AC and blinds!

Miss The Predictive Text From Your Old Nokia? Build Your Own T9 Keypad

June 3, 2021 by 23 Comments

Do you miss the mind-blowing typing speed of your old Nokia brick with predictive text turned on? Well, so did [Guy Dupont], so he created a USB keypad with T9 predictive text built-in to turn typing into a one-handed affair. Video after the break.

T9 was the first predictive text technology to gain widespread use in the late ’90s and early 2000s. The goal was to minimize the number of keypresses required for typing on multi-press keypads by matching key sequences to a dictionary of the possible words. It prioritizes words based on the frequency of use and can adapt to user preferences. [Guy] implemented T9 in Circuit Python, mainly for the RP2040 microcontroller used on the Raspberry Pi Pico, which will appear as a normal USB keyboard when plugged into any device. The dictionary is stored in the flash memory and can be updated using a tool also created by [Guy]. It can also change modes for old multi-press typing, numeric pad, or macro pad.

We would be interested to see just how fast it’s possible to type one handed with T9, and what application our readers can imagine. It doesn’t look like this implementation can learn the user’s preferences, which we think would be a worthy feature to add.

We’ve covered several unique custom keyboards recently, some more practical than others. On the silly side, these include a grenade-shaped function pad, a five-button chording keyboard, and a tiny two-key keyboard. Continue reading “Miss The Predictive Text From Your Old Nokia? Build Your Own T9 Keypad” →

How To Get Into Cars: Ice Racing Mods

June 3, 2021 by 6 Comments

Typically, when it comes to inclement weather, ice is the worst of the worst of driving conditions. Regular tyres have little to no grip in such situations, and accidents are common. However, some choose to laugh at such challenges, and take to racing out on frozen lakes and rivers. The sport of ice racing can be a demanding one, though, so you’ll need to prep your car appropriately. Here’s how.

Ice, Ice, Baby

The highest tier of ice racing is the Andros Trophy, conducted in France each year. Competitors in the top class compete in mid-engined V6-powered cars with AWD and four-wheel steering.

Ice racing is largely limited to colder climates where lakes, rivers, or even actual racetracks freeze over in the winter. While some limited ice racing does occur indoors on skating rinks, it’s largely limited to motorcycles and ATVs because such facilities are just too small for cars.

The weather-dependent and esoteric nature of ice racing means that it exists at the fringes of organised motorsport, with most events being community-run at the grassroots level. Often, new competitors will start in a “run-what-you-brung” class, with unmodified street cars competing in limited or no-contact events, such as time trials or drag races. Higher tiers then generally necessitate more serious preparation and safety equipment, such as rollcages and fire extinguishers, and competitive door-to-door racing on larger tracks. However, some professional competitions do exist, running bespoke tube-framed cars built for purpose. The most notable of these is the Andros Trophy, held in the French Alps and run by the namesake jam company. Continue reading “How To Get Into Cars: Ice Racing Mods” →

Retro Useless Clock Eventually Shows You The Time

June 3, 2021 by 8 Comments

It’s true; hackers like clocks. And hackers like useless machines. But would they like an intersection of the two? We’re thinking yes, probably, though we would argue that this QR clock was at no point fully useless. Yes, a QR clock as in, whip out your phone and, ignoring the conveniently-available phone time, open the bar code reader so you can check the time on this thing. So, it’s semi-useless. But at least it doesn’t detect cameras and then hide the QR code. That would be evil.

This project started life as a display piece for the hex wall down at [megardi]’s hackerspace, but, state of the world being what it is, [megardi] hasn’t made it down there yet. And meanwhile this little guy was looking cuter and cuter, so [megardi] decided to make him more useful and freestanding. The ESP32 inside gets the official time from NIST and displays it on the 1.5″ OLED screen. It also has a single alarm now, along with some other non-QR code clock faces that display the time in various ways.

We really like the look of this clock. Honestly, with those uniform tics around the edge, it sort of reminds us of the doomsday clock — you know, the ‘minutes to midnight’ quarter clock face that shows the current perceived threat level of how close we are to destroying the world with the technologies we’ve created. That clock is kind of cute, too, which is a little bit weird considering what it represents.

Speaking of our delicate planet, here’s a gorgeous little Earth clock that casts a shadow on whatever slice of the planet is currently shrouded in darkness.