Rapid Fire, Remote Controlled Ping Pong Ball Turret

remote-ping-pong-ball-turret

[Andrew] and his brother had some time (and a lot of ping pong balls) on their hands, so they decided to have some fun and built a remote-controlled ping pong ball turret.

Arduino aside, the turret is cheap and easy to build as [Andrew’s] writeup explains. The firing mechanism was constructed using a pair of foam wheels and motors, which is used to launch the ping pong balls much like a baseball pitching machine. The balls are stored above the wheels in a cardboard tube and released by a mechanical flap when triggered.

When [Andrew] is ready to release the turret’s payload, he sends a command to his computer over VNC, which relays the command to the Arduino over a serial connection, triggering the flap. While the control scheme could certainly benefit from direct, wireless phone-to-Arduino communications, it seems to work well enough for [Andrew’s] needs.

Check out the video dramatization below to see [Andrew] “surprise” his brother with a hail of ping pong balls after the jump.

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Reading Diodes To Create A Thermal Imaging System

[Udo Klein] was working with some 1N4148 transistors and was interested in the specs relating to their performance at different temperatures. The forward voltage actually changes quite a bit depending on temperature and wondered if this could be reliably measured. He hacked his own LED shield for the Arduino to use as a 1×20 thermal imaging system.

The screenshot above is mapping the voltage measurements from a row of diodes (see the video after the break to get the full picture). He’s holding an ice pack over the row of diodes and observing the change. The on-screen display is facilitated by a Python script which is pulling data from the Arduino. Since there aren’t enough analog inputs to read all twenty diodes separately they have been multiplexed. Four I/O pins each enable five of the diodes, readings are taken with five analog inputs before moving on to the next set.

What can this be used for? That is precisely the wrong question… sometimes you’ve just got to go where your curiosity takes you. Continue reading “Reading Diodes To Create A Thermal Imaging System”

Weapon Of Mass Graffiti

What uses a fire extinguisher, a bike pump, and provides hours of probation, community service, and possibly jail time? If you said an automatic graffiti writer you’re correct! [Olivier van Herpt] calls this little job the Time Writer. We call it defacing property… but tomato, tomahto.

Details are a bit scarce, but you get a fine overview of the system from the video after the break. [Olivier] tagged the post as Arduino; it’s obviously running the dot matrix printer made up of seven solenoid valves on a metal rod. These are fed ink via a tube connected to a fire extinguisher which serves as the reservoir. The bike pump is used to pressurize the enclosure so that a pump isn’t necessary when out and about.

Obviously you shouldn’t try this at home, but let’s talk about possible improvements as an academic exercise. First off the mix of the ink/paint needs to be reigned in to get rid of the dripping. We’d also like to see the inclusion of some proper spray can nozzles to tidy up the results. That, paired with an IMU board should be able to smooth out the printed designs.

This might make an interesting add-on to that rainbow graffiti writer.

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Telegraph Key Makes For A Fantastic Twitter Input

In the interests of interface archaeology, [Martin] sent in the Tworse Key, a telegraph key that posts to Twitter using Morse code. It’s a fantastic build that nearly looks like something out of the 1900s.

We’ve seen a ton of Morse keyboards over the years, but never one so well-engineered for a single purpose. The guts and brains of the Tworse Key is an Arduino Ethernet that connect to Twitter over the API. The Tworse Key automagically posts all the Morse messages to Twitter. The Tworse Key may have fallen off the table a few times in the past 24 hours, but we do see a few purposeful messages like ‘sos’ and [Bell]’s preferred telephone salutation.

We could say that nobody uses straight telegraph keys anymore, but outside a few hardcore CW HAM radio guys nobody uses Morse anymore. This isn’t meant to be used as an everyday input device, though. It’s more of an exercise in interface archaeology. That being said, an iambic key would be a far more ergonomic solution. Check out the video of the Tworse Key after the break.

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A SOPA We Still Can’t Get Behind

[Brad] had an extremely productive January 18th. Considering how many websites went dark to protest SOPA, we can’t blame him. While considering what he could get done if popular Internet time sinks went dark on command, [Brad] thought of the Stop Online Productivity Avoidance box. This build will redirect all traffic to sites like reddit, hacker news, and (gasp!) hack a day to a simple web page that asks the eternal question, “shouldn’t you be working right now?”

The box has two modes: in SOPA mode, the whole Internet is at [Brad]’s fingertips. In NOPA mode, an Arduino communicates with a Python script running on the router to pull up an Internet blacklist. A simple button would be too easy to override, so there’s a ‘nuclear mode’ that shuts off these time sinks for one hour. The only way around the blacklist is to restart the router, a process that takes 15 minutes and will kill the entire Internet for the duration. Not something you’d like to do if you’re slightly bored.

All the code for the SOPA box is up on github and you can check out [Brad]’s demo of the SOPA box after the break.

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Simulated Dashboard For A Simulated Race

Simulators might have lost their cool for a lot of gamers, but [Fergo] is trying for a comeback. He built an electronic dashboard for a car racing simulator.

[Fergo] spends most of his track time on iRacing, an MMO racing simulator. Possibly due to a little bit of influence from Formula 1 steering wheels, he wanted to add to his dashboard that included Microsoft racing wheel. The dashboard includes RPM lights, a gear indicator, five general buttons, a rotary encoder, and a pit limiter, rev limiter and low fuel indicators.

The build is powered a VB.NET app that connects the iRacing API to an Arduino. To get all those buttons and LEDs talking to the Arduino, [Fergo] used an IO expander that communicates over an I2C bus. It’s a surprisingly simple design that should scale well if [Fergo] ever decides to expand his cockpit. We’re not sure if it could handle controlling a 737, but it would be more than sufficient for a Cessna 172 or Mercury capsule.

Check out [Fergo] tearing around the track with his buttonbox dashboard after the break.

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Sixty4Racer An 8×8 Game

[Pete] has a cool new tutorial creating a re-imagining of the Atari classic “River Raid” for the PIX-6T4 micro controller based game system. The PIX is a netduino on a larger board featuring 2 analog controllers, a speaker, an sd card and an 8×8 monochrome LED display. With a resolution that low, it may make the good ole VCS look like a 360, but there is still a lot to learn about making a game at this low of a level.

The tutorial [Pete] has put together covers concept, gameplay, progression goals, screen handling and a boat load of code to show how it all goes together. Though this is for a C# based system many of the basics apply to just about any system you can imagine. So if you’re looking to learn how to handle graphics in C, sprite animation, collision, or randomly putting levels together out of tile blocks then you should take a look.

Join us after the break for a quick video.

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