2022 FPV Contest: Get The Train Driver’s View In Your N-Scale Railway

December 28, 2022 by Robin Kearey 23 Comments

Model railroaders typically observe their project from high above. It would be neat to see what the world looks like to the residents of your little town, but getting down to their point of view is difficult, especially if you’re working in one of the smaller scales. For those working in the N scale, there’s now an easy way of observing your project as the train driver would see it: [Vassily98] managed to squeeze a wireless camera into an N-scale railcar.

The main challenge here was the extremely limited space available: the track in N-scale layouts is 9 mm wide, meaning that the whole system had to fit in just 23 x 20 mm², the frontal area of a typical train car. One of the few cameras that fit within that profile was the RunCam Nano 4, which [Vassily98] connected to an ultra-tiny Team BlackSheep 5.8 GHz video transmitter.

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This WiFi Signal Strength Meter Ain’t Afraid Of No Ghosts

December 23, 2022 by Dan Maloney 5 Comments

The original Ghostbusters movie is a classic that’s still delivering nearly 40 years after its release — just let that sink in for a minute. Almost every aspect of the film, from hand props to quotes, is instantly recognizable, even to people who haven’t based their lives on the teachings of [Venkman], [Stantz], and [Spengler]. To wit, we present this PKE meter-style WiFi scanner.

Of course, [Kevin McAleer]’s project is strictly in the “Just for Fun” category. But that doesn’t mean it’s not at least somewhat useful. The design is pretty close to the original PKE meter, with a little bit of creative license taken to make it easier to build. Guts include a Raspberry Pi Pico W and a generous 320×240 LCD display. The body of the meter is entirely 3D printed; design files are of course available. The meter’s arms are geared together to move with a single hobby servo.

On the software side, [Kevin]’s GUI lets users see a list of WiFi hotspots in the area and select one from the list. From there, the position of the arms is determined by the RSSI for the hotspot, similar to how the prop was supposed to indicate the proximity to a spook, specter, or ghost. There’s perhaps a bit of a missed opportunity by not adding LEDs to the arms, but we’ll let that slide.

The video below has full design and build details, but fair warning that it’s a bit on the long side. That’s probably just a reflection of how much work [Kevin] put into this, though. Of course, you may rather build a PKE meter that “actually” detects ghosts, in which case we’ve got you covered.

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More Detail On That Fantastic Lego OLED Brick

December 20, 2022 by Dan Maloney 38 Comments

It’s always great when we get a chance to follow up on a previous project with more information, or further developments. So we’re happy that [“Ancient” James Brown] just dropped a new video showing the assembly of his Lego brick with a tiny OLED screen inside it. The readers are too, apparently — we got at least half a dozen tips on this one.

We’ve got to admit that this one’s a real treat, with a host of interesting skills on display. Our previous coverage on these bedazzled bricks was disappointingly thin on details, and now the original tweets even seem to have disappeared entirely. In case you didn’t catch the original post, [James] found a way to embed a microcontroller and a remarkably small OLED screen into a Lego-compatible brick — technically a “slope 45 2×2, #3039” — that does a great job of standing in for a tiny computer monitor.

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A Simple High-Fidelity DIY Mic Pre Amp

December 16, 2022 by Lewin Day 13 Comments

If you’re doing any serious work with microphones, you’ll typically find yourself in want of a dedicated preamp. [ojg] needed just such a thing for acoustic measurement duties, and set about working up a cheap DIY design by the name of ThatMicPre.

The design is based around the THAT1510 preamp IC, known for its good frequency response and low harmonic distortion and noise. The design is also compatible with THAT1512, SSM2019, and INA217 chips as well. [ojg] gave the design switch-controlled gain levels, providing greater accuracy than a potentiometer adjustment, and the ability to supply phantom power for mics that require it. The PCB is designed to rely on through-hole parts and common connectors for easy assembly.

The design is open source, and has already been built by others on the DIYAudio forums. Built into a simple case, it looks like a handsome and well-built piece of audio equipment. We’ve featured quite a few unique preamps over the years, and if you’ve been building your own, we’d love to see those too!

Building A Lamp To Help With Seasonal Depression

December 13, 2022 by Lewin Day 13 Comments

The sun plays a big biological role in our lives, regulating our circadian rhythms and doing a whole bunch more as well. Some people find the reduced sunlight of the winter months to have negative emotional effects, and rely on artificial lighting to counteract this. [Samasrinivas] built a lamp of their own design for this very purpose.

The lamp is constructed around an abstract sculptural form made in air-dry clay. Light is provided via a string of Neopixel RGBW LEDs. Run by an Adafruit Feather Huzzah, they’re programmed to trigger with the sunrise to provide a bright light in the morning on grey days when the outside world isn’t quite delivering the same. The Adafruit queries an online weather API to get the right sunrise time every day without requiring user intervention. The lamp can also be programmed to provide warm light during later hours.

We’ve featured a few circadian lighting projects before, including one that goes for a whole-of-house effect with smart bulbs. For some, they’re a valuable way to help boost mood and maintain consistent sleep cycles. Video after the break.

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Crazy Bike Frame Made Out Of 147 Nuts

November 16, 2022 by Lewin Day 39 Comments

Bike frames are most commonly made out of steel. If you’ve got money for something nicer though, you might go with something in aluminium or carbon fiber. [The Q] went completely off-the-wall with this build, though, constructing a bicycle frame out of 147 nuts.

Yes, a variety of nuts in various sizes were laid out and welded together to make the frame. The overall layout is a conventional diamond frame, albeit constructed out of many nuts stuck together rather than with tubes. Notably though, several important areas aren’t made in this way. The front and rear dropouts are made of sheet steel, and the bottom bracket, seat post mount, and headstem are all made of steel tube. After welding, the bike was given an attractive coat of grey paint. It was then laced up with the usual running gear and given a set of chunky mountain bike tires.

We wouldn’t want to push this frame too hard over bumps and jumps. The video only shows the nuts being joined with tack welds, and the front forks look particularly fragile. One suspects a decent shock loading could snap parts of the frame apart. Overall, though, it’s an eye-catching bike that has plenty of easy places to attach a lock. For an ultra-fashionable city-bound cruiser, it would be hard to beat.

We’ve featured some weird and wonderful bikes over the years, including this tasteful plywood design. Video after the break.

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Circadian Lighting For The Home Via Home Assistant

November 13, 2022 by Lewin Day 10 Comments

Artificial lighting is great, in that it lets us work and live well into the night. However, our bodies are dependent on the natural lighting cycles of the sun as part of their basic operation, and artificial lighting can interfere with this. [Tyler Cipriani] decided to use Home Assistant with some smart lights to try and make home lighting more suitable for our natural circadian rhythms.

The basic intent was to give the home bright white/blueish light during the day, matching the sun’s output. The light would then be altered to warmer yellow/red tones in the evening. The eye has cells that respond to blue light to regulate our circadian rhythms with the presence of the sun, so reducing blue light at night may help reduce disruption to sleep and other body processes.

Home Assistant has a Circadian lighting component available built specifically for this task. It’s a useful smart home tool for achieving such a job, too, as it readily works with a wide variety of hardware from different vendors. In [Tyler]’s case, light switches are Zigbee devices that talk to Home Assistant via a Zigbee2MQTT hookup and a Combee Zigbee gateway. Lights around the home are a mixture of Philips Hue devices and other brands of smart lights.

[Tyler] states the effects are “subtle but noticable.” He notes that it’s easier to feel sharp and work during the day, but harder to continue the lighting warms and dims at night. He points out that this is a design feature to help keep him on a healthy sleep schedule.

We’ve seen other circadian rhythm lights before. In fact, NASA uses them on the ISS, but you can build your own for a lot less than they spent. If you’ve got your own circadian lighting hacks, don’t hesitate to drop us a line!