Save Your Thumbs With This Netflix Password Sender

August 29, 2017 by Dan Maloney 22 Comments

Chances are anyone who has an entry-level to mid-range smart TV knows that setting them up with your streaming account credentials is a royal pain. Akin to the days of texting on a flip phone, using the number pad or arrow keys to compose your user name and password seems to take forever. So why not avoid the issue with this automated Netflix logger-inner?

As if the initial setup wasn’t bad enough, when [krucho5]’s LG smart TV started asking for his Netflix credentials every few days, he knew something needed to be done. An Arduino to send “keystrokes” was the obvious solution, but when initial attempts to spoof the HID on the set proved fruitless, [krucho5] turned to the IR remote interface. He used an IR receiver module to capture the codes sent while entering user name and password, and an IR LED plays it back anytime the TV ask for it. The video below shows how much easier it is now, and the method should work just fine for any other online service accounts.

We like [krucho5]’s build, but the fit and finish are a little rough. Perhaps slipping them into a pair of Netflix-enabled socks would be a nice touch?

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Color Sensor From An RGB LED And A Photocell

August 29, 2017 by Dan Maloney 27 Comments

When you need to quantify the color of an object, you’ve got quite a few options. You can throw a Raspberry Pi camera and OpenCV at the problem and approach it through software, or you can buy an off-the-shelf RGB sensor and wire it up to an Arduino. Or you can go back to basics and build this reflective RGB sensor from an LED and a photocell.

The principle behind [TechMartian]’s approach is simplicity itself: shine different colored lights on an object and measure how much light it reflects. If you know the red, green, and blue components of the light that correspond to maximum reflectance, then you know the color of the object. Their sensor uses a four-lead RGB LED, but we suppose a Neopixel could be used as well. The photosensor is a simple cadmium sulfide cell, which measures the intensity of light bouncing back from an object as an Arduino drives the LED through all possible colors with PWM signals. The sensor needs to be white balanced before use but seems to give sensible results in the video below. One imagines that a microcontroller-free design would be possible too, with 555s sweeping the PWN signals and op-amps taking care of detection.

And what’s the natural endpoint for a good RGB sensor? A candy sorter, or course, of which we have many examples, from the sleek and polished to the slightly more hackish.

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A Flame Diode Pilot Light Sensor For A Burning Man Installation

August 28, 2017 by Jenny List 22 Comments

A naked flame is a complex soup of ionised gases, that possesses an unexpected property. As you might expect with that much ionisation there is some level of electrical conductivity, but the unusual property comes in that a flame can be made to conduct in only one direction. In other words, it can become a diode of sorts, in a manner reminiscent of a vacuum tube diode.

[Paul Stoffregen] has made use of this phenomenon in a flame detector that he’s built to be installed on a Burning Man flame-based art installation. It forms part of a response to a problem with traditional pilot lights: when the wind blows a pilot light out, a cloud of unignited gas can accumulate. The sensor allows the pilot light to be automatically re-ignited if the flame is no longer present.

The circuit is a surprisingly simple one, with a PNP transistor being turned on by the flame diode being placed in its base circuit. This allows the intensity of the flame to be measured as well as whether or not it is present, and all at the expense of a microscopic current consumption. A capacitor is charged by the transistor, and the charge time is measured by a Teensy that uses it to estimate flame intensity and trigger the pilot light if necessary. Interestingly it comes from a patent that expired in 2013, it’s always worth including that particular line of research in your investigations.

All the construction details are in the page linked above, and you can see the system under test in the video below the break.

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Doomed Incandescent Light Blinker

August 28, 2017 by Elliot Williams 10 Comments

[Jānis]’s entry for the Flashing Light Prize was doomed from the start. Or should we say Doomed? It was a complicated mess of Rube-Goldbergery that essentially guaranteed that he’d have no time for making a proper video and submitting and entry. But it also ran Doom. Or at least ran on Doom.

(Note: [Jānis] sent us this hack in the e-mail — there’s no link for this blog post. You’re reading it here and now.)

It starts with a DC motor salvaged from a DVD player that spins a wheel that flips a switch back and forth, which in turn flips the polarity of the power on the motor. It’s like a most-useless machine, but with no human involved. This contraption periodically presses a button on a gutted mouse.

Pressing the mouse button on one computer fires a rocket in a multiplayer Doom game, and triggers a light on a wall when it does. A second Doom player, on another computer, sits facing the wall. Solar cells dangled in front of Player 2’s monitor emit high and low voltages as the LCD blinks on and off. That output goes into the ADC of an Arduino clone that drives a transistor that drives a relay that turns on and off a lightbulb.

We had a lot of fun watching all of the entries for the Flashing Light Prize, and we were also stoked by the presence of so many Hackaday regulars in the Honourable Mention list. (Sad to see [Sprite]’s ping-flasher didn’t make the cut!)

If you, like [Jānis] are still sitting on a design, don’t fret. It looks like the prize will make a return next year. Woot!

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Harvesting Copper From Microwave Ovens

August 26, 2017 by Dan Maloney 51 Comments

Obsolete appliances were once a gold mine of parts, free for the taking with a few snips of your diagonal cutters. Times have changed, though, and most devices yield only a paltry supply of parts, so much so that only by harvesting raw materials can you get much value out of them. And so we have this example of reclaiming copper from used microwave ovens.

The primary source of copper in most microwaves is the transformer, which we usually see re-tasked for everything from spot welders to material handling electromagnets. But the transformer is not the only source of the red metal; [eWaste Ben] also harvests it from relay coils and the main coil and shading coils of the fan motor. The bounty is melted down in an electric foundry and cast in a graphite mold into a lovely ingot.

Unless you’re into repeatedly casting copper trinkets, a large bar of reclaimed copper might not be something you have a burning need to possess. But bearing in mind that copper can go for about $2.50 a pound at the scrap yard, there’s some money to be made, especially with dead microwaves essentially free for the taking. As [Ben] points out, taking the extra step to melt and cast the copper harvested from microwaves makes no sense if all you’re going to do is sell the scrap, but it’s nice to know how to do it just the same.

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Determining Kibble Level Via Time-of-Flight

August 26, 2017 by John Baichtal 12 Comments

[WTH] is building an IoT kitty food dispenser. There are a few of these projects floating around that measure out portions very sensibly — some use screws to dispense a set amount of food at a time, some measure the weight of the remaining stockpile. This build is definitely not that. This kitty food monitor uses a time of flight sensor to determine the remaining level of food in a hopper. [WTH]’s feeder lets the cat eat all the grub it wants, then alerts the hooman when kibble levels drop below a certain level.

The project starts with one of those pet food dispensers that consist of a hopper that gravity feeds into the food bowl. As the animal eats that food, more dispenses into the bowl. Attached to the lid is an ESP8266 connected to an Adafruit time of flight sensor. This reports the kibble level in centimeters, which is good enough for [WTH]’s purposes. Sensor data is logged to a Google Drive spreadsheet, published as a graph through M2X (AT&T’s IOT service), and texted to [WTH]’s smart watch via IFTTT.

Look for a plethora of Tweeting, Instagramming, and otherwise automated feeding of the cat overlords right here on Hackaday. Check out automatic cat feeder dispenses noms, wants cheezburger, and a cat feeder made with laminator parts.

Custom Cut Pinwheel Makes A Useful HVAC Duct Flow Meter

August 25, 2017 by Dan Maloney 12 Comments

Everyone is familiar with pinwheels, and few of us haven’t crafted one from a square of paper, a stick, and a pin. Pinwheels are pretty optimized from a design standpoint, and are so cheap and easy to build that putting a pinwheel to work as an HVAC duct flow meter seems like a great idea.

Great in theory, perhaps, but as [ItMightBeWorse] found out, a homemade pinwheel is far from an ideal anemometer. His experiments in air duct flow measurements, which previously delved into ultrasonic flow measurement, led him to try mechanical means. That calls for some kind of turbine producing a signal proportional to air flow, but a first attempt at using a computer fan with brushless DC motor failed when a gentle airflow couldn’t overcome the drag introduced by the rotor magnets. But a simple pinwheel, custom cut from patterns scaled down from a toy, proved to be just the thing. A reflective optosensor counts revolutions as the turbine spins in an HVAC duct, and with a little calibration the rig produces good results. The limitations are obvious: duct turbulence, flimsy construction, and poor bearings. But for a quick and dirty measurement, it’s not bad.

Looking for an outdoor anemometer rather than an HVAC flow meter? We’ve got one made from an old electric motor, or a crazy-accurate ultrasonic unit.

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