Arduino Parking Lot Attendant

Here’s an automatic parking gate for toy cars. There’s no need to press a button, the electronics detect the presence of a vehicle on either side of the gate, raising it after verifying that the lot is not already full. It’s the same idea as counting how many people enter a room in order to switch the lights but the hardware is just a bit different.

The system is controlled by a pair of sensors in the paper which serves as the parking lot. There are three sheets of heavy stock, the top and bottom both have aluminum foil on them, with the center layer  as a separator. There are holes cut in the separator where the hash marks are seen above. By adding a little pressure to the car when you drive it up to the gate this completes a circuit instructing the Arduino that there’s a vehicle in position.

You can see a demonstration, as well as the guts of the build, in two videos after the break.

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Arduino Voice Changer Turns You Into [Vader]

Halloween is just around the corner, so of course we’re looking forward to a bunch of awesome costumes put together by Hackaday readers. In an effort to match his voice to his costume, [Phil Burgess] over at Adafruit (and former Hackaday alumnus) put together an Arduino-powered voice changer to give his voice the gravitas of [James Earl Jones] or the lightheartedness of a member of the Lollipop Guild.

If you’ve ever played with a turntable, you’ll know playing a 33 RPM record at 45 or 78 RPM turns your treasured copy of Dark Side of the Moon into a lighthearted aural experience with a pitch that is much too high. Likewise, playing a single at 33 or 16 RPM means those once dulcet tones are now recordings of tormented souls in an acoustic hell.

[Phil]’s voice changer operates on the same principle by recording sounds from a microphone into a circular array and playing them back at a different rate; faster if the desired effect is a Munchkin, and slower if this year’s Halloween costume will be a Sith lord.

The completed build incorporates a 10k pot to dynamically change the timbre of the voice changer, as well as an Adafruit Wave Shield to play back a few pre-recorded sounds of lightsabers clashing. In all, a very cool project for your Halloween costume that’s also a very good introduction to DSP and real-time audio modifications with a microcontroller.

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Malting Kiln Controller For Preparing Beer Brewing Grains

A quick primer is in order: when it comes to hobby brewing there’s two main types, extract brewing and all-grain brewing. The former uses a syrup that has been extracted from the grains at a factory while the latter adds the steps to do this yourself. But in both cases the brewing grains have already been malted. This is a careful process of soaking the grains and then kiln drying them. [Richard Oliver] built his own malt kiln controller to add the preliminary step to his home brewing ritual. Now the only thing he’s not doing himself is growing the grains (and perhaps culturing the yeast).

His original design used a food dehydrator for the drying step, but this didn’t work because the temperature wasn’t at the correct level. The new build uses the ceramic heating element from a 300W hot air gun. A blower directs air through the element and into the wooden box that serves as the kiln. An Arduino monitors the heated air to keep it right in the sweet spot. He’s included a graphing GUI for easy monitoring, which is shown in the video after the break.

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Building A Better PID Smoker Controller

[Matt] wanted to have more control over his meat smoker so he built this advanced PID smoker controller. It uses the solid state relay seen in the bottom-right of this image to switch the smoker’s heating element. But all of the other goodies that are included add several features not usually found in these builds.

This is a replacement for the commercial PID unit he used on the original build. That monitored the temperature in the smoker, using predictive algorithms to maintain just the right heat level. But this time around [Matt] is looking for extra feedback with a second sensor to monitor meat temperature. Using an Arduino with an SD shield he is able to data log the smoking sessions, and his custom code allows him to specify temperature profiles for resting the meat after it has hit the target temperature. It kind of reminds us of a reflow oven controller… but for food.

Using Arduino Shields With The Raspi

With hundreds of Arduino shields available for any imaginable application, it’s a shame they can’t be used with the Raspberry Pi. Breaking out the Raspi GPIO pins to Arduino-compatible headers would allow makers and tinkerers to reuse their shields with a far more capable computing platform.

The folks over at Cooking Hacks realized a Raspi to Arduino shield bridge would be an awesome device, so they made their own, complete with a software library that allows you to port your Arduino code directly to the Raspberry Pi.

There are a few limitations with the Raspberry Pi’s GPIO headers; the Raspi doesn’t have analog inputs, so the Cooking Hacks team added an 8-channel ADC. Along with analog inputs and the headers required to pop a shield on the board, there’s also a socket for an XBee module.

The software library contains most of the general Arduino functions such as digitalWrite() and digitalRead(). There Serial, Wire, and SPI libraries are also implemented, allowing any device that communicates through UART, I2C, or SPI to talk directly to the Raspberry Pi.

While the Raspi Arduino bridge doesn’t allow for PWM in the same capacity as an Arduino, you’re always welcome to whip up a servo or LED shield for this neat little adapter.

Single Sided Arduino Is A Great Introduction To PCB Etching

After you’ve taken the plunge and decided to learn how to etch your own circuit boards, you’ll quickly find even the simplest boards are still out of your grasp. This is due mostly to the two-layer nature of most PCBs, and turn making a homemade Arduino board an exercise in frustration and improving your vocabulary of four-letter words.

After looking around for an easy-to-manufacture single-sided Arduino board, [Johan] realized there weren’t many options for someone new to board etching. He created the Nanino, quite possibly the simplist Arduino compatible board that can be made in a kitchen sink.

Billing it as something between the Veroduino and the Diavolino, [Johan]’s board does away with all the complexities of true Arduinos by throwing out the USB interface and FTDI chip. A very small parts count makes the Nanino much less expensive to produce in quantity than even the official Arduino single sided board.

For an introduction to etching your own PCBs at home, we couldn’t think of a better first board. As an Arduino, you’re guaranteed to find some use for it and the ease of manufacture and low parts count makes it the perfect subject for your hackerspace’s next tutorial series.

Wrapping Up Maker Faire With [Ben Heck], Giant Arduinos, And An Apple Lisa

All good things, and apparently our coverage of Maker Faire, must come to an end. Here’s a few more things we saw in New York this last weekend that piqued our interest:

A 10x scale Arduino

[Robert Fitzsimons] of Part Fusion Electronics made a gigantic Arduino. It wasn’t quite functional, but [Robert] did manage to make a few 10:1 scale LEDs (with built-in circuit protection), 1 inch pitch headers, and a few other miscellaneous components out of foam and paint.

Since he’s from Dublin, Ireland, [Robert] didn’t want to take this giant board home with him. He graciously gave it to me in the hopes of turning it in to a proper working Arduino. I’ll do my best, [Robert].

There are hundreds of Lisas buried in a landfill in Utah.

Tekserve, an indie Apple store located in the heart of Manhattan, really knows how to put on a good show. For the entirety of their stay at Maker Faire, they had people showing off one of the first digital cameras, Apple Newtons, and an awesome collection of vintage Macs. No, your eyes do not deceive you; that’s a real Lisa there in the bunch.

Sadly, they didn’t have the boot disk to turn any of these on. Pity.

Yes, there were celebrities at Maker Faire

Well, celebrities to the Hackaday crowd, at least. [Ben Heck] showed off the electronic automatic sunglasses he built. It’s a pair of lensless glasses, a servo, light detector, and a pair of clip-on sunglasses. When [Ben] is out in daylight, the sunglasses swivel down. Inside, the amount of light received by the detector decreases and the shades rotate up.

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