Laser Crown Shines At Night

September 16, 2019 by Lewin Day 6 Comments

Sometimes you need something really flashy to complete an outfit. Whether it’s a sparkly pair of earrings or a stylish necklace, accessories are key to competing on the fashion battlefield. For those who want to bring some serious firepower, [p3nguin’s] laser crown might be just what the doctor ordered.

At the outset, we should state the crown only uses lasers in its construction, for cutting felt and acrylic. The light source is a Neopixel ring from Adafruit, capable of bringing the vibrant colors without risk of eye damage. The ring is then assembled with a series of snap-together acrylic parts and a felt cap, with slots for hair pins to keep the crown in place on the wearer’s head. A Trinket drives the show, with a LiPo battery used as a lightweight power supply.

It’s a nice build that’s sure to draw plenty of attention. We see some great wearables around these parts; this EL jacket is a particular favorite. Video after the break.

Continue reading “Laser Crown Shines At Night” →

Writing Characters Straight To The Linux Framebuffer

September 16, 2019 by Lewin Day 15 Comments

These days, working with a display in software is fairly easy. Thanks to the convenience of the modern OS, we’re blessed with graphical user interfaces, where things such as buttons and windows and text are all taken care of for us. Of course, once you start to wander off the beaten track, particularly in embedded systems with no GUI, things can get a little more difficult. For these situations, [JSBattista] wrote some code to blast text directly to the Linux framebuffer.

It’s a project borne out of necessity. Working with a Raspberry Pi with no X server, it was found that the console text size made it difficult to display data. By writing directly to the framebuffer, it would be possible to display text of a larger size without having to implement a full GUI, and overheads could be kept to a minimum.

Working in this manner comes with some limitations. Glyphs are taken from an array in bitmap format, rather than font files. In this case, a font akin to that of the Alien sentry gun interface was chosen, for an attractive sci-fi look. Lowercase characters are currently unimplemented. Testing thus far has been on Raspberry Pi and Beaglebone non-GUI systems, with performance varying depending on platform.

It’s a project we suspect might prove useful to the developers of lightweight embedded systems. It’s something that may take some tweaking and experimentation to implement, but the hacker set rarely shy away from a challenge. If you’re eager to get down and dirty with some heavy programming, this tutorial on Linux graphics will help.

Name Stone Helps You Greet Coworkers

September 16, 2019 by Lewin Day 17 Comments

When starting a new job, learning coworkers names can be a daunting task. Getting this right is key to forming strong professional relationships. [Ahad] noted that [Marcos] was struggling with this, so built the Name Stone to help.

The Name Stone consists of some powerful hardware, wrapped up in a 3D printed case reminiscent of the Eye of Agamotto from Doctor Strange. Inside, there’s a Jetson Nano – an excellent platform for any project built around machine learning tasks. This is combined with a microphone and camera to collect data from the environment.

[Ahad] then went about training neural networks to help with basic identification tasks. Video was taken of the coworkers, then the frames used to train a convolutional neural network using PyTorch. Similarly, a series of audio clips were used to again train a network to identify individuals through the sound of their voice, using MFCC techniques. Upon activating the stone, the device will capture an image or a short sound clip, and process the data to identify the target coworker and remind [Marcos] of their name.

It’s a project that could be quite useful, given to new employees to help them transition into the new workplace. Of course, pervasive facial recognition technology does have some drawbacks. Video after the break.

Continue reading “Name Stone Helps You Greet Coworkers” →

Grey Water Toilet Helps Keep You Flush

September 16, 2019 by Kristina Panos 43 Comments

The average first world household swims in an ocean of non-potable water from things like HVAC condensation, shower drains, and periods of rain. All of it just goes to waste. These same households pay the city to deliver drinkable water to places that don’t need it, like the toilet tanks. Isn’t it time to put all that perfectly good grey water to use? With a zero city water toilet, you can give that slightly-used H₂O one last hurrah before flushing it down the drain.

When the toilet is flushed, an ultrasonic sensor in the toilet tank monitors the change in water level and triggers a pump to fill the toilet back up from a barrel in the basement. A clear plastic tube inserted into the toilet tank does double duty as both the water source and tank overflow drain point.

The 55-gallon plastic barrel in the basement collects water from both a shallow well and condensation from [nodemcu12ecanada]’s gas furnace. A NodeMCU controls the 12V submersible pump to send water up to the toilet, and another ultrasonic sensor monitors the water level in the barrel.

This setup doesn’t require changes to any of the existing plumbing, and reverting back is easy. We particularly like the use of phone plugs and jacks as quick connectors, and will likely steal the idea. You can get more information about this and [nodemcu12ecanada]’s other home-automation projects here.

Basic Acrylic Bending, No Special Tools Needed

September 16, 2019 by Donald Papp 24 Comments

Acrylic sheets are relatively inexpensive, pretty, and can be heat-shaped very effectively. There are blades and tools made specifically for cutting, heating, and bending acrylic but [Marija] shows that even without them acrylic can be cut and bent with a bit of care and patience.

Acrylic sheets are brittle and crack easily, but a hacksaw is a good way to cut it by hand. After cutting, [Marija] uses a small portable gas stove at its lowest setting to provide gentle heat until the acrylic becomes soft, then it can be formed into different shapes using common shop and household items. It’s a process that requires patience and practice, so she shares some useful tips:

Remove the protective film after cutting, but before heat forming. Otherwise the film will be much harder to remove.
Heating too aggressively will result in bubbles that ruin the acrylic.
Uneven heating will result in a bad bend, or “hot spots” which can result in bubbles as mentioned above.
This heating method naturally softens a wide area, but it’s still possible to get straight and flat bends by using wood forms and letting the acrylic cool before moving it.

[Marija] used this method of heating and bending acrylic to complete an earlier lamp project of hers that we featured in the past. Acrylic might laser-cut beautifully, and there may be inexpensive tools for heating and bending it, but it’s always nice to have some tried and true techniques that don’t require anything special.

Continue reading “Basic Acrylic Bending, No Special Tools Needed” →

Trill: Easy Positional Touch Sensors For Your Projects

September 16, 2019 by Ted Yapo 8 Comments

Creating capacitive touch-sensitive buttons is easy these days; many microcontrollers have cap-sense hardware built-in. This will work for simple on/off control, but what if you want a linear, position-sensitive input, like you’d find on a computer touchpad or your smartphone screen? Not so easy — at least until now. Trill is a family of capacitive touch sensors you can add to your projects as a linear slider, a square touchpad, or by creating your own touch surface.

Trill was created by the same team that designed Bela, an embedded platform for low-latency interactive applications, especially with audio. The new trio of Trill sensors rely on capacitive sensing to track finger movement, and communicate over I2C with your microcontroller or development board of choice. The Trill I2C library targets Arduino and Bela, but should be easy to port to any I2C host.

The hardware and software are both open-source — or will be as the Kickstarter that launched this morning has already met its goal. The firmware for the Cypress CY8C20636A (PDF) controller that powers these sensors will be released CC-BY-NC-SA. But, starting with the controller itself sounds like a lot of work that Trill has already done for you, so let’s have a look at what we know so far, along with a healthy dose of speculation.

Continue reading “Trill: Easy Positional Touch Sensors For Your Projects” →

Software Defined Radio Hack Chat

September 16, 2019 by Dan Maloney 3 Comments

Join us on Wednesday, September 18 at noon Pacific for the Software Defined Radio Hack Chat with Corrosive!

If you’ve been into hobby electronics for even a short time, chances are you’ve got at least one software-defined radio lying around. From the cheap dongles originally intended to watch digital TV on a laptop to the purpose-built transmit-capable radio playgrounds like HackRF, SDR has opened up tons of RF experimentation. Before SDR, every change of band or mode would need new hardware; today, spinning up a new project is as simple as dragging and dropping a few blocks around on a screen, and SDRs that can monitor huge swaths of radio spectrum for the tiniest signal have been a boon to reverse engineers everywhere.

Corrosive is the handle of Harold Giddings, amateur callsign KR0SIV, and he’s gotten into SDR in a big way. Between his blog, his YouTube channel, and his podcast, all flying under the Signals Everywhere banner, he’s got the SDR community covered. Whether it’s satellite communications, aircraft tracking, amateur radio, or even listening in on railway operations, Harold has tried it all, and has a wealth of SDR wisdom to share. Join us as we discuss the state of the SDR ecosystem, which SDR to buy for your application, and even how to transmit with an SDR (hint: you’ll probably want a ham license.)

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, September 18 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.