Year: 2018

Thermoelectric Generator Shines Where The Sun Doesn’t

March 31, 2018 by 81 Comments

For off-grid renewable electricity, solar seems to make sense. Just throw some PV panels on the roof and you’re all set to stick it to the man, right? But the dirty little secret of the king of clean energy is that very few places on the planet get the sort of sunshine needed to make residential PV panels worth their installation cost in the short term, and the long-term value proposition isn’t very good either.

The drearier places on the planet might benefit from this high-power thermoelectric generator (TEG) developed and tested by [TegwynTwmffat] for use on a wood burning stove. The TEG modules [Tegwyn] used are commercially available and rated at 14.4 volts and 20 watts each. He wisely started his experiments with a single module; the video below shows the development of that prototype. The bulk of the work with TEGs is keeping the cold side of the module at a low enough temperature for decent performance, since the modules work better the higher the difference in temperature is across the module. A finned heatsink and a fan wouldn’t cut it for this application, so a water-cooled block was built to pump away the heat. A successful test led to scaling the generator up to 10 modules with a very impressive heatsink, which produced about 120 watts. Pretty good, but we wonder if some easy gains in performance would have come from using heat sink compound on the module surfaces.

Using thermal differences to generate electricity is nothing new, but a twist on the technique is getting attention lately as a potential clean energy source. And who knows? Maybe [TegwynTwmffat]’s or one of the other Hackaday Prize 2018 entries will break new ground and change the world. What’s your big idea?

Continue reading “Thermoelectric Generator Shines Where The Sun Doesn’t” →

There’s More To MIDI Than Music – How About A Light Show?

March 31, 2018 by 6 Comments

MIDI instruments and controllers are fun devices if you want to combine your interest in music and electronics in a single project. Breaking music down into standardized, digital signals can technically turn anything with a button or a sensor into a musical instrument or effect pedal. On the other hand, the receiving end of the MIDI signal is mostly overlooked.

[FuseBerry], a music connoisseur with a background in electronics and computer science, always wanted to build a custom MIDI device, but instead of an instrument, he ended up with a MIDI controlled light show in the shape of an exploded truncated icosahedron ([FuseBerry]’s effort to look up that name shouldn’t go unnoticed). He designed and 3D-printed all the individual geometric shapes, and painstakingly equipped them with LEDs from a WS2818B strip. An Arduino Uno controls those LEDS, and receives the MIDI signals through a regular 5-pin DIN MIDI connector that is attached to the Arduino’s UART interface.

The LEDs are mapped to pre-defined MIDI notes, so whenever one of them is played, and their NoteOn message is received, the LEDs light up accordingly. [FuseBerry] uses his go-to DAW to create the light patterns, but any software / device that can send MIDI messages should do the trick. In the project’s current state, the light pattern needs to be created manually, but with some adjustments to the Arduino code, that could be more automated, something along the lines of this MIDI controlled Christmas light show.

Continue reading “There’s More To MIDI Than Music – How About A Light Show?” →

You Bring It, This Blings It: Retrofitting A Hot Foil Stamping Machine

March 31, 2018 by 15 Comments

Hot foil stamping is a method often used to embellish and emboss premium print media. It’s used on things like letterhead and wedding invitations to add a touch of luxury. The operation is actually quite simple, where a custom die is heated, pressed into a heat transfer foil, and then transferred on to the print media. Some of the very first manuscripts used gold leaf embossing to decorate intricate calligraphy. You can also see it often used to decorate the sides of religious texts.

Professional foil stamping machines are often pricey and the cheaper ones you can get from eBay are usually poorly made. [Lindsay Wilson] found this out when he purchased a low-cost hot foil stamping machine that was too difficult to use reliably. It got shelved for years until he had another hot foil stamping project. This time he was prepared. He took the machine apart and robust-ified it by attaching it to a heavy-duty arbor press. He also retrofit the heating assembly with his own temperature controller to improve the accuracy for the foils he wanted to use.

Continue reading “You Bring It, This Blings It: Retrofitting A Hot Foil Stamping Machine” →

Simple Decoder Serves As Solo Ham’s Test Buddy

March 31, 2018 by 11 Comments

For a hobby that’s ostensibly all about reaching out to touch someone, ham radio can often be a lonely activity. Lots of hams build and experiment with radio gear much more than they’re actually on the air, improving their equipment iteratively. The build-test-tweak-repeat cycle can get a little tedious, though, especially when you’re trying to assess signal strength and range and can’t find anyone to give you a report.

To close the loop on field testing, [WhiskeyTangoHotel] threw together a simple ham radio field confirmation unit that’s pretty slick. It relies on the fact that almost every ham radio designed for field use incorporates a DTMF encoder in the microphone or in the transceiver itself. Hams have used Touch Tones for in-band signaling control of their repeaters for decades, and even as newer digital control methods have been introduced, good old analog DTMF hangs in there. The device consists of a DTMF decoder attached to the headphone jack of a cheap handy talkie. When a DTMF tone is received, a NodeMCU connected to the decoder calls an IFTTT job to echo the key to [WTH]’s phone as an SMS message. That makes it easy to drive around and test whether his mobile rig is getting out. And since the receiver side is so portable, there’s a lot of flexibility in how tests can be arranged.

On the fence about ham as a hobby? We don’t blame you. But fun projects like this are the perfect excuse to go get licensed and start experimenting.

Continue reading “Simple Decoder Serves As Solo Ham’s Test Buddy” →

Sharpening With Bluetooth

March 31, 2018 by 21 Comments

Few things are as frustrating in the kitchen as a dull knife. [Becky] and her chef friend collaborated to build a Bluetooth module to tell you when you are sharpening a knife at the optimum angle. That might sound a little specialized, but the problem boils down to one that is common enough in a lot of situations: how do you tell your exact orientation while in motion? That is, with the knife moving rapidly back and forth over the sharpening stone, how can you measure the angle of the blade reliably?

Looking for a challenge, [Becky’s] first attempt was to just use an accelerometer. It worked, but it wasn’t very precise. Her final answer turned out to be a full inertial measurement unit — the BNO055 — that combines an accelerometer, a magnetometer, and a gyroscope along with enough smarts to fuse the data into actual position data.

Continue reading “Sharpening With Bluetooth” →

Giving A 6th Generation IPod A New Lease On Life

March 30, 2018 by 13 Comments

It can be disheartening when a favoured device begins to break-down. Afflicted by an all-but-dead battery and a fritzing-out hard drive, Redditor [cswimc] sensed the imminent doom creeping up on their 6th generation iPod, and responded by reviving and upgrading the decrepit device instead!

It’s no easy task to crack open one of these things, so they found themselves taking their time and carefully wedging the pry tool between the front and back covers, working their way around the exterior. Once separated, gingerly disconnecting the few ribbon cables allowed the iPod to be opened fully. From there, they turned to  swapping out the original hard drive for an iFlash dual SD card board — one of the cards turned out to be a dud, but 128GB is still a step up from 80GB — and a new 3000mAh battery. Combined with replacing the power-hungry HDD, the battery life has been overwhelmingly increased over the original’s 650mAh capacity!

Continue reading “Giving A 6th Generation IPod A New Lease On Life” →

The Internet Of Three-Pointers

March 30, 2018 by 1 Comment

When tossing something into the rubbish bin, do you ever concoct that momentary mental scenario where you’re on a basketball court charging the net — the game’s final seconds ticking down on the clock — making a desperate stretch and flicking some crumpled paper perfectly into the basket only for no one to notice your awesome skills? Well, now you can show off how good you are at throwing out garbage.

Well, not strictly garbage. The genesis of this IoT basketball hoop was in fact an inflatable ball on [Brandon Rice]’s desk that he felt would be more fun to fidget with if he could keep score. The hoop and backboard were laser cut on his Epilog cutter, and sport a Particle Photon to track and upload his running point tally to the Internet. An Arduino and IR sensor detect objects passing through the hoop — ultrasound proved to be too slow to keep up with [Rice]’s shots.

Continue reading “The Internet Of Three-Pointers” →