Arduino Hacks

3063 Articles

“That’s Not A Knife…”

April 21, 2016 by 38 Comments

[Robin Baumgarten] likes to play dangerously. His latest creation, Knife To Meet You cuts to the quick of cooperative gaming. 3 humans play together against the machine. The object of the game is to hold your button down as long as possible. The game makes this difficult by sweeping a knife across the play field, right at finger level. (Video below.)

Knife to meet you is controlled by a flesh eating Arduino. In addition to reading the controls and driving a servo to move the knife, the Arduino also displays encouraging messages on a 2×20 character LCD.

The idea is to scare people, not to actually slice them up. To this end, the knife is actually a capacitive sensor. When the game detects the knife has contacted soft human flesh, it stops the knife before blood starts flowing. The game indicates a player has been defeated by making several chopping motions toward the loser. If the losing player still has all their digits, a new round begins.

The project was created as part of a 24 hour game jam. The final product is quite nice, built into a wood case that closes up for travel. It even has a carrying handle, so you can bring it to parties and find fresh victims players.

We’re not sure what it is about knives and Arduinos. It was only a few months ago that we saw an Arduino driving a knife wielding tentacle. Could the world’s friendliest microcontroller board be turning on us?
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Bluetooth Water Cannon Junk Build Shoots Into Our Hearts

April 19, 2016 by 9 Comments

We’ve seen a few remote controlled turret builds in the past, but this one from [Noel Geren] is pretty neat: it shoots water and uses Bluetooth Low Energy (BLE) for control. Check it out in action in the video below.

[Noel] used the guts of a Nerf Thunderstrike water gun for the firing mechanism, combined with a 3D-printed enclosure and a servo that rotates the turret top. The pump from the gun is connected to a simple relay that replaces the trigger. Both the relay and the servo are connected to an RFDuino with a servo shield, which is programmed to respond to simple commands to rotate and fire.

It’s a nice junk build, and [Noel] has released all of the files for download if you want to build your own. It would make a nice weekend build or a project to do with the kids.

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Morse Code Waterfall Is Cooler Than Your Fifth Grade Science Fair Project

April 19, 2016 by 36 Comments

For her science fair project, [David]’s daughter had thoughts about dipping eggs in coffee, or showing how dangerous soda is to the unsuspecting tooth. Boring. Instead she employed her father to help her build a Morse Code waterfall.

A more civilized wea-- tool from a more elegant age. Young Jed--engineer.
A more civilized wea– tool from a more elegant age. Young Jed–Engineer.

[David] worked with his daughter to give her the lego bricks of knowledge needed, but she did the coding, building, and, apparently, wire-wrapping herself. Impressive!

She did the trick with two Arduinos. One controls a relay that dumps a stream of water. The other watches with an optical interrupt made from an infrared emitter and detector pair to get the message.

To send a message, type it in the keyboard. The waterfall will drop spurts of water, and then show the message on the decoder display. Pretty cool. We also liked the pulse length dial. The solution behind the LEDs is pretty clever. Video after the break.

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Alarm System Upgrade Tips The Functionality Scale

April 18, 2016 by 29 Comments

Residential-grade commercial alarm systems are good at a few things but terrible at others, like keeping pace with telephone technology. So what to do when a switch to VOIP renders your alarm system unable to call in reinforcements? Why not strip out the old system and roll your own value-added alarm and home automation system?

Generally, the hardest part about installing an alarm system is running the wires to connect sensors to the main panel, so [Bill Dudley] wisely chose to leverage the existing wiring and just upgrade the panel. And what an upgrade it is. [Bill]’s BOM reads like a catalog page from SparkFun or Adafruit – Arduino MEGA 2560, Ethernet shield, a sound board, stereo amplifier, X10 interface, and a host of relays, transformers, and converters. [Bill] is serious about redundancy, too – there’s an ESP8266 to back up the wired Ethernet, and a DS3231 RTC to keep the time just in case NTP goes down. The case is a bit crowded, but when closed up it’s nicely presentable, and the functionality can’t be beat.

Rehabilitating old alarm systems is a popular project that we’ve covered plenty of times, like this Arduino upgrade for a DSC 1550 panel. But we like the way [Bill] really went the extra mile to build add value to his system.

The AAduino Is An Arduino In An AA Battery

April 18, 2016 by 35 Comments

You might think that there could be no form factor that has not as yet had an Arduino fitted in to it. This morning a new one came our way. [Johan Kanflo]’s AAduino is an Arduino clone with an onboard RF module that fits within the form factor of an AA battery. Putting the Arduino inside its own battery pack makes a very neat and compact self-contained unit.

At the heart of the board is an ATmega328 clocked at 8MHz to reduce power consumption and fused to drop out at 1.7V. The radio module is a HopeRF RFM69C which as supplied is a little bit too big for the AA form factor so [Johan] has carefully filed away the edge of the PCB to make it fit. Enough room is left within the shape of an AA cell for a couple of DS18B20 temperature sensors and an indicator LED. He provides a handy buyer’s guide to the different versions of a 3xAA box with a lid, and all the files associated with the project are available in his GitHub repository.

Especially with the onboard radio module we can see that the AADuino board could be a very useful piece of kit. Perhaps for instance it could be used as a very low power self-contained UKHASnet node.

We’ve featured quite a few Arduino clones over the years that try to break the size mould in some way. This stripboard Arduino almost but not quite equals the AAduino’s size, as does this PCB version barely wider than the DIP package of its processor. But the AADuino is a bit different, in that it’s a ready-made form factor for putting out in the field rather than just another breadboard device. And we like that.

Using Rapid Prototyping To Make A Clock

April 17, 2016 by 10 Comments

[Markus] is attending the Royal Institute of Technology in Stockholm. For his Advanced Prototyping class he had to make something using rapid prototyping technology — i.e. 3D printers, laser cutters, and breadboards. He chose to make a fantastic looking clock.

He started by designing the entire thing in CAD. The base is 3D printed on a Ultimaker. The world clock display is a piece of laser engraved acrylic which he heated up and curved to fit. Using an Arduino and a 16×2 LCD matrix he created a simple clock program with the ability to show different time zones. The way you select them is very clever.

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Minions Turn Your Keyboard Into A Bluetooth Keyboard

April 14, 2016 by 22 Comments

Evil geniuses usually have the help of some anonymous henchmen or other accomplices, but for the rest of us these resources are usually out of reach. [Evan], on the other hand, is on his way to a helpful army of minions that will do his bidding: he recently built a USB-powered minion that turns a regular PS/2 mouse and keyboard into a Bluetooth mouse and keyboard.

[Evan] found his minion at a McDonald’s and took out essentially everything inside of it, using the minion as a case for all of the interesting bits. First he scavenged a PS/2 port from an old motherboard. An Arduino Nano is wired to an HC-05 Bluetooth chip to translate the signals from the PS/2 peripherals into Bluetooth. The HC-05 chip is a cheaper alternative to most other Bluetooth chips at around $3 vs. $40 for more traditional ones. The programming here is worth mentioning: [Evan] wrote a non-interrupt based and non-blocking PS/2 library for the Arduino that he open sourced which is the real jewel of this project.

Once all the wiring and programming is done [Evan] can turn essentially any old keyboard and mouse into something that’ll work on any modern device. He also put an NFC tag into the minion’s head so that all he has to do to connect the keyboard and mouse is to swipe his tablet or phone past the minion.

If you’re looking for an interesting case for your next project, this McDonald’s Minion toy seems to be pretty popular. PS/2 keyboards are apparently still everywhere, too, despite their obsolescence due to USB. But there are lots of other ways to get more use out of those, too.

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