Arduino Parking Lot Attendant

October 15, 2012 by Mike Szczys 25 Comments

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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Controlling A Robot With Your Mind

October 15, 2012 by Brian Benchoff 16 Comments

For [Ern]’s MEng group project, his group had to develop a robotics platform capable of achieving some end goal. Because innovation is a large part of the grade, [Ern] convinced his team members to work with a brain controlled interface and build a mind controlled robotics platform.

For wont of having an easy build, [Ern] and his team chose a Lynxmotion Tri-Track robot capable of moving around the classroom while receiving commands from a computer. The mind-control portion of the build comes from a NeuroSky MindWave Mobile, a cheap and fairly open EEG system that reads alpha, beta, and delta waves generated by a user’s brain and sends that data over to a computer for processing.

After a bit of testing that included an Arduino to move the robot forward if the MindWave’s ‘attention’ value was over 60%, [Ern] and his team looked for a way to implement multi-directional control.

In order to get the robot moving left, right, and backwards in addition to moving forwards, the team looked at the included ‘blink detection’ abilities of the MindWave to cycle through a few commands. This technique turned out to be far too sensitive – the blink detection of the MindWave is simply too good. To get around that problem, the team used the signal strength of the received EEG signals. The theory being when a user blinks their eyes, the EEG contacts will move slightly, degrading the signal received by the hardware.

The team finally got a reasonable mind-controlled robot up and working, as demonstrated in the video after the break. Check out how each blink allows [Ern] and his colleagues to cycle through driving modes. Pretty neat for controlling something with your mind.

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Waterfall Swing Set

October 14, 2012 by Jeremy Cook 21 Comments

[Doped Boron] wrote in to tell us about this waterfall swing by [Dash 7]. Naturally, we had no idea what a “waterfall swing” was. Shown at the World Maker Faire in 2011, the device is a swing set capable of accommodating one or two people using it at a time. What makes it interesting, is that water comes out of the top support bar, forming a wall of water for the riders to pass through. This wall is then broken when the swing user flies through it making for a dry experience.

According to the article, 273 solenoid valves are used to control the wall of water. These solenoids are controlled by a computer with sensors that detect where the riders are in the air and what speed they are going. As with most good hacks, it may not serve a “grown-up” purpose, but a set would definitely make a trip to the park more interesting!

Be sure to check out the videos after the break. The first shows the swing in its traditional role, but the second may be even more interesting, showing full control of the swing solenoids for water writing! Continue reading “Waterfall Swing Set” →

Tens Of Thousands Saved By Building A BAM Microscope Out Of LEGO

October 1, 2012 by Mike Szczys 35 Comments

A Brewster Angle Microscope (BAM) can run you around $100,000. If you don’t have that lying around you could just use some LEGO pieces to build your own. Having been faced with no budget to buy the hardware, and needing the data to finish his PhD, [Matthew] figured out a way to build something passable on the cheap.

These microscopes bounce a light source off of a pool of water and into the lens of a camera. The thing is the angle of the sender and receiver must be just perfect at 53.1 degrees. [Matthew] was able to afford a used camera, and started experimenting with some lab equipment to mount the rig. But he just couldn’t get the adjustments right. Since he had to move the mounting hardware by hand it was impossible not to over or under shoot the corrections. But then he had a eureka moment. LEGO pieces have very accurate tolerances, and you can get geared and motorized parts. He leveraged the quality of the toy into a BAM whose alignment can be tweak with great precision.

It may not look like much, but you can see stearic acid floating through the microscope’s field of vision in the clip after the break. This is exactly the type of observations he needed to perform. Of course if you just need a microscope you can use a laser and a drop of water.

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Hand Cranked Electric Toy Has No Batteries Or Power Supply

September 28, 2012 by Mike Szczys 20 Comments

We think this hand cranked robot design is nothing short of absolute brilliance. The toy is remote-controlled through a short section of wire. It can drive forward and turn, but not at the same time. Still that’s impressive considering it uses no battery or power supply and, of the two servo motors, only one is actually in the robot itself.

The second servo, which is visible to the right, acts as a dynamo. When you crank it electricity is generated. The inputs of that servo are connected to the inputs of the one in the robot to power it. If you crank in one direction the colorful toy will drive forward. But there is a one-way catch on one of the side wheels so when the servo is cranked backward the little guy actually executes a reverse turn. The magic of building a project like this is perfect for a weekend activity with the kids. Don’t miss the demo embedded after the jump.

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Rubik’s Cube For The Blind

September 27, 2012 by Mike Szczys 18 Comments

Check out this Rubik’s Cube for the blind. The idea didn’t start off as an accessibility hack, but instead as a way for [Brian Doom] to figure out where the face of each cube goes when manipulating the puzzle. It gave him tactile feedback and his ability to use it in dim lighting was when it dawned on him that this could be useful to others.

Now when we first thought of a puzzle for the blind the term ‘Braille’ immediately jumped to mind. But this doesn’t use it. That’s great, because not all visually impaired people can understand Braille. Instead, this uses dimension and texture to identify each of the puzzle faces. There are mushroom-shaped knobs, Phillips screws, adhesive rubber bumpers, raised text label maker labels, and a few other items that go along with each color. This doesn’t prevent those with sight from playing either. It’s something of one Rubik’s cube for all. Well, all except for the robots made to solve a stock cube.

[via Dvice]

Motorized Wheelchair Built From LEGO Pieces

September 26, 2012 by Mike Szczys 18 Comments

You’re certainly not going to sneak up on anyone if using this LEGO motorized wheelchair. The high-pitched whine of all those tiny motors sounds like an army of robotic mosquitoes out for blood.

Six of the LEGO Mindstorm bricks are used to drive the motors, with a seventh acting as the master. It’s not pictured above, but there is a joystick on the right hand side which allows the rider to navigate. The master brick monitors the four sensors on that joystick. It then uses a pair of motors to actuate switches monitored by the slave bricks. Each slave has one switch for forward, and another for backward and drives two motors. To get around problems with angular velocities dues to turning, all of the wheels are multidirectional.

The plan is to add Bluetooth control in the near future. The master/slave setup should make that relatively easy as it only affects one of the bricks. The idea is to facilitate Android control to the chair like we’ve seen in other Mindstorm builds.

Don’t miss the demo embedded after the break.

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