Mixed I/O Testing Module

Needing to test the display interface for a multitude of different sensors [Fileark] built himself this analog and digital input/output simulator. Along the bottom is a double row of trimpots that adjust analog voltages. Each voltage is measured by the Arduino inside and its value is displayed on the graphic LCD screen to confirm that the hardware you’re testing is making correct measurements. There’s also digital I/O in two different forms. To the upper left are momentary push buttons but the DIP switch bank below that allows the same connections to be toggled on and off. It’s not an automated test bed, but if you’ve got a lot of I/O, or a lot of hardware to test this will save you some real time.

Don’t miss the demonstration video after the break.

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Arduino Asteroids

[nootropic] has a new game out for hackvision, “Asteroids”! We covered the hackvision back when it first started appearing in October of 2010, and hardware wise it has not changed. It is still an Arduino (software) compatible system sporting a atmega328, video and audio out connections (uses the TV-out library), all on a nice printed circuit board that, with the buttons, resembles a game controller.

While its impressive enough to run arcade inspired games like space invaders, pong, and tetris while using Arduino and a library, Asteroids takes the game up a notch.

Features that make Asteroids well, Asteroids include a mod of the TV-out library so that bitmaps can fly over each other without erasing the pixels under them to give that old time vector arcade feel, and “point in polygon” style collision detection, which is a fantastic / efficient way of collision detection against irregular shapes, limited platform or not.

Last but not least, [nootropic] used the set_vbi_hook() function of the tv out library in sound design, going from simple “beeps” and “boops”, to “beeps” and “boops” on a constant 60Hz refresh (in the case of NTSC) that allows him to build more complex sound effects that give a nice arcade sound of explosions and laser blasts.

Join us after the break for a quick video, and remember, this is Arduino based so if you already have an Arduino, you can add the supporting hardware (buttons, resistors, and RCA jacks) and run any of the games currently offered, or make your own.

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Simple RFID Access System Clone

rfidbboards

A few months back, [John] was reading an article about a simple RFID security system kit, and decided he would like to build one himself.  While many of the system’s details, including full schematics were provided, he was dismayed to find that the source code for the project was not published as it was held under copyright by the manufacturer.  Believing that open source is better, he modified the original design, replacing their PIC controller with an ATmega328 armed with an Arduino bootloader.

His system replicates all of the original kit’s functionality, while offering plenty of opportunity for modification beyond the initial design.  The article contains a complete parts list, wiring schematic, and the Arduino code required to get things up and running.  He even has a video of his clone at work, demonstrating the acceptance and rejection of RFID tags as well as the system’s learning mode.

Going Cellular With Your Arduino Projects

You can add a huge measure of extensibiltiy to a project by using a cellular connection. Anywhere the device can get service you can interact with it. In the past this has been a pretty deep slog through datasheets to get everything working, but this tutorial will show the basics of interacting with phone calls and text messages. It’s the 26th installment of what is becoming and mammoth Arduino series, and the first one in a set that works with the SM5100B cellular shield.

We love the words of warning at the top of the article which mention that a bit of bad code in your sketch could end up sending out a barrage of text messages, potentially costing you a bundle. But there’s plenty of details and if you follow along each step of the way we think you’ll come out fairly confident that you know what you’re doing. Just promise us that you won’t go out and steal SIM cards to use with your next project. Find part two of the tutorial here and keep your eyes open for future installments.

Charging Timer For R/C Batteries

arduino_controlled_socket

Santa brought [Quinten’s] son a shiny R/C truck for Christmas, but this new toy had one drawback – its batteries could only be connected to the charger for a maximum of 6 hours, lest he turn his house into a pile of smoldering ash.  With grave warnings from the manufacturer dancing in his head, he searched around for a timer that would allow him to cut power to the battery after charging for its allotted time.  Coming up empty, he decided to create his own timed electric socket regulated by an Arduino he had sitting around.  He grabbed a project box and wired up a nice looking socket timer, complete with an LCD status display.  To make things easy for his son, he added two buttons to the front of the controller – one for selecting the amount of charging time, and one to set the timer in motion.  As with his previous hacks, [Quinten] has provided plenty of documentation in the form of pictures, code, and even a video of the timer in action.

Inaccurate Breathalyzer Is Still Quite Nice

Sure, [Hunter Scott’s] Breathalyzer can only differentiate between hammer and sober, but look how nice it came out. He’s using an MQ-3 alcohol sensor which, from previous projects, we know is very difficult to accurately calibrate. But if you want to monkey around with embedded systems you’ve got to have a goal. [Hunter] chose a gorgeous aluminum project enclosure, adding a big LCD display to the to the lit. The switch on the bottom selects between on, off, and charging modes. He’s using a USB charger from Adafruit to top off the lithium battery inside. Everything runs on 3.3V with the exception of the sensor which gets its 5V supply from a boost converter. An Arduino is the brains that pulls everything together.

See [Hunter’s] video description of the project embedded after the break.

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Yet Another Cat Door

Cat Flap Fever

RFID cat flaps are one of those projects we see all of the time. They are generally pretty simple to rig up, not too expensive, and have a good “wow” factor for any non-technical friends or family, not to mention tremendously useful. Why did we decide to share this one? Well, for one, it is simple. It doesn’t tweet, email, or text message, it just gets the job done. Two, it is excellently documented, including a detailed parts list and a step by step schematic just about anyone could use to build their own. [landmanr] does mention that he recommends some sort of project enclosure to protect the electronics from damage, which would be bad for the poor cat stuck outside.