Year: 2012

Vitamin C Used To Detect The Presence Of Vanillin

August 28, 2012 by 36 Comments

[Markus Bindhammer] recently made a discovery while conduction chemistry experiments in his home lab. Ascorbic acid can be used to detect the presence of Vanillin. The reaction starts as a color change, from a clear liquid to a dark green. When he continued to heat the mixture he ended up with the surface crystallization seen above.

Vanillin is an organic compound which you will commonly find in vanilla extract, with the synthetic variety being used in imitation extract. Ascorbic acid is a type of vitamin C. When [Markus] first observed the color change he though it could be due to metallic contamination, but running the experiment again without the use of metal tools or probes, produced the same result.

You can see in the clip after the break that it doesn’t take long to turn green. The vanillin must be heated to 130 degrees C before adding the ascorbic acid or the color change will not occur. He believes this can be a reliable way to detect the presence of Vanillin in a substance.

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Inebriator Servers Up All The Cocktails

August 28, 2012 by 39 Comments

The robotic bartender, lovingly named the Inebriator, is a work of mastery. We think you’ll be surprised by the simplicity and grace of its beverage dispensing system.

The most obvious part is the lineup of nine liquor bottles across the top with LED backlight for style. Each has a valve on it that is meant to be pressed on by the rim of a glass in order to dispense its payload. To dose the glass with alcohol the Inebriator drives a trolley along one axis beneath the line of bottles. When in position it has an actuator arm the rises up and depresses the bottle’s valve mechanism. Once all the liquor is in the glass it moves to the left side to be topped off with mixers. These are stored in bottles in a cooler under the table. They are pressurized with nitrogen, and an electronically actuated value lets the liquid flow. Drinks are selected on a character display, and there’s a weight sensor in the trolley to ensure that a drink isn’t mixed without a vessel to receive it.

You don’t want to miss seeing this in action after the break.

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Bluetooth Control In A Power Strip

August 28, 2012 by 16 Comments

[Mansour] had a ceramic space heater mounted near the ceiling of his room. Since heat rises this is not the best design. He upgraded to an infrared heater which works a lot better, but lacks the timer function he used on the old unit. His solution wasn’t just to add a timer. He ended up building a Bluetooth module into a power strip in order to control the device wirelessly. He ends up losing all but two outlets on the strip, but everything fits inside the original case so we think it’s a reasonable trade-off.

He uses relays on both the live and neutral wires to switch the two outlets. These are driven via MOSFETs to protect the ATmega168 which controls the board. The microcontroller and Bluetooth module both need a regulated DC power source, so he included a transformer and regulator in the mix. After the break you can see him demonstrating the system using two lamps. There’s even a terminal interface which lets you select different control commands by sending the appropriate character. This interface makes script a breeze.

At least this power strip doesn’t spy on you.

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Turning On PC Speakers Whenever There Is Music Playing

August 28, 2012 by 44 Comments

If you’re like a lot of people, most of the time your computer speakers are on without actually playing any music. This wastes a bit of power, and [Bogdan] thought he could create a circuit to cut down on that wasted electricity. The result is a very tiny auto-on circuit able fit inside a pair of speakers.

The circuit is built around the ATtiny13, very nearly the smallest microcontroller available with an on-board ADC. When music is played on the computer, the ATtiny senses a bit of voltage in the audio line and switches a relay to power the speaker.

Of course, there is always the problem of music with a high dynamic range; if the sound played from the computer has too low of a volume, the ATtiny might turn the speakers off even if music is playing. [Bogdan] solved this problem by adding a timer to his code; if nothing is detected by the ADC for three minutes, the speakers turn off.

Robo Doc Reads Children’s Pulses Without Scaring Them

August 28, 2012 by 25 Comments

[Markus] recently took his 14-month-old daughter to the pediatrician for a routine checkup. During the examination, the doctor needed to measure her pulse and quickly clamped an infrared heart rate monitor onto her finger. Between the strange device clamped to her finger and incessant beeping of machines, [Markus]’ daughter got scared and started to cry. [Markus] thought these medical devices were far too scary for an infant, so he designed a funny robot to read an infant’s heart rate.

[Markus] liked the idea the Tengu, a robot with a LED matrix for facial expressions, and used it as inspiration for the interface and personality of his RoboDoc. To read a child’s pulse rate, [Markus] used a photoplethysmography sensor; basically an IR LED and receiver that reflects light off a finger bone and records the number of heartbeats per minute.

The build is tied together with a speaker allowing the RoboDoc to give the patient instructions, and a servo to turn the head towards the real, human doctor and display the recorded heart rate.

We think the RoboDoc would be far less disconcerting for an infant that a huge assortment of beeping medical devices, and we can’t wait to see [Markus]’ next version of non-scary doctor’s tools.

Soft Robots Given Veins The Let Them Change Their Stripes

August 28, 2012 by 21 Comments

If it were alive this robot would be classified as an invertebrate. It lacks a backbone and interestingly enough, all other bones are missing as well. The Harvard researchers that developed it call it a soft robot. It’s made out of silicone and uses pathways built into the substance to move. By adding pressurized air to these pathways the appendages flex relative to each other. In fact, after the break you can see a video of a starfish-shaped soft robot picking up an egg.

Now they’ve gone one step further. By adding another layer to the top, or even embedding it in the body, the robot gains the ability to change color. Above you can see a soft robot that started without any color (other than the translucent white of the silicone) and is now being changed to red. As the dye is injected it is propagating from the right side to the left. The team believes this could be useful in a swarm robotics situation. If you have a slew of these things searching for something in the dark they could pump glowing dye through their skin when they’ve found it. The demo can be seen after the jump.

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Learning The Ins And Outs Of USB With A Simple Dev Board

August 28, 2012 by 17 Comments

We can’t count the number of projects we’ve seen on Hackaday with a USB port.  Unfortunately, most of these builds – from RepRap controllers to wireless data loggers – don’t use the full capabilities offered to them with USB. [Ben] came up with a very cool USB breakout board that allows you to explore the USB protocol with just a single inexpensive ATtiny.

Instead of relying on an FTDI chip or otherwise sending serial data down a USB pipe, [Ben]’s project is meant to be the hardware compliment to his book on programming USB devices. His hardware board is exceedingly simple, just an ATtiny 2313, a USB port, and a handful of other components, but allows [Ben] to receive data on eight pins on a breadboard and send them over USB to a computer.

[Ben] had sent in his USB figure eight controller, a board that displays the numbers 0 through 9 according to what data is received via USB, a while ago. It’s a truly useless build aside from learning how USB works, but an excellent tool if you’d like to program your own USB device.