Add Explosive Power To Your Hi-five

December 22, 2010 by Mike Szczys 58 Comments

It’s been a while since there was any advances made in the field if celebratory high-five-ing. [Eli Skipp] just finished her contribution, moving the art forward by adding the sound of explosions to her high-fives. Ignore the audio sync problems in the video after the break to see her Arduino and Wave Shield based offering. It uses a flex sensor to detect a high-five and has a bit of software filtering to avoid misfires when moving your hand or setting it down on a flat surface. It may look a bit ridiculous right now because of the bulk, but we could see a sleeker, cheaper version hitting toy and novelty stores everywhere.

Less useful than a sign-language translating glove, but easier to code and some would say more fun too. Continue reading “Add Explosive Power To Your Hi-five” →

Keep Your Kids In Line With A Time Clock

December 19, 2010 by Mike Szczys 68 Comments

When the cat’s away the mice will play, but a least you’ll know when they came home if you use this time clock. It’s called the Kid-e-log and [John Boxall] developed it to help a friend who wanted to keep track of their teenage children’s after school activities while they were still at work. He figured having them punch a time clock would at least let you know if they came straight home as they were supposed to. An RFID tag was issued to each (no, they didn’t implant the tags) and used to record the time. To keep fraud to a minimum the hardware has a battery back-up for its real-time clock, and the tag read events are stored to EEPROM for retention between power cycles. This doesn’t prevent common tricks like taking the reader with you, or sending your tag with a sibling, but it’s a start. See it in action after the break.

Continue reading “Keep Your Kids In Line With A Time Clock” →

DIY Breathalyzer May Be The Hit Of The Party

December 16, 2010 by Mike Szczys 25 Comments

Okay, this may not be saving any lives, but it makes for a fun novelty at your next rager. Most Breathalyzers aim to keep you from driving when you’ve had too many. The Squidalyzer encourages party-goers to drink more and more by treating a high blood-alcohol-content with great fanfare. An Arduino, a gas sensor, and Processing all come together for this hack. A television interface tells you when to blow into a cup which houses the sensor, and gives a reading of what it measures. Blow higher than the last guy and you’ll break the record. Watch the demo after the break to see the fun [Geoff] had with it. And remember, friends don’t let friends solder drunk.

Continue reading “DIY Breathalyzer May Be The Hit Of The Party” →

Garage Monitor Has An Extra Arduino

December 14, 2010 by Devlin Thyne 57 Comments

[Jody] wanted to know when his garage door was open. He details his setup which uses a temperature sensor read by an Arduino to send over XBee radio to a computer running a Windows Service. We have seen this twice before, and is noteworthy as a lesson. The XBee radios have the ability to read analog data, relay digital signals, and a lot more. This means the Arduino is completely unnecessary. For example, the Tweet-a-Watt uses two of an XBee’s ADCs to measure voltage and current in a Kill-a-Watt power meter. Programming an XBee is really simple, with the help of tutorials from SparkFun and Adafruit. A bit of programming and soldering should get [Jody] back his Arduino. We hope this note will help you find more creative uses of XBees without microcontrollers.

[Via Make]

AVR HV Rescue Shield 2

December 14, 2010 by Mike Szczys 10 Comments

[Jeff Keyzer] has a new version of the HV Rescue Shield available. This tool allows you to use an Arduino to reset the fuse bits on AVR microcontrollers. This is necessary if you make a mistake and disable the reset pin, or choose the incorrect clock settings (this will probably happen to you at some point). In order to bring the chip back to life you’ll need to use High Voltage Programming. The last version of the shield only worked with High Voltage Parallel Programming (HVPP) but this rendition can also use High Voltage Serial Programming (HVSP) for 8-pin chips that don’t have enough inputs for parallel communications.

As we talked about in our AVR Programming Tutorials this is no replacement for a high-end programmer like the STK500 or an AVR Dragon, but if you already have an Arduino a kit will only cost you $20 (or you can etch and build it yourself). We would have liked to see a breakout header for the HVP signals for off-board use. The absence of a breakout header doesn’t preclude this, but since you need the on board boost converter for the 12V signals, and because this shield can’t be used with a breadboard due to pin spacing, it’s hard to patch into signals for non-DIP use. We also think some clever firmware hacking and this could be used for HV programming, like we needed for that LED light bulb.

Jacob’s Ladder Using EL Wire

December 12, 2010 by Mike Szczys 19 Comments

For Halloween [Paul] wanted to build a Jacob’s Ladder without the peril that working with high voltage might bring. He was inspired by a sequencer board for electroluminescent wire and decided to build a Jacob’s Ladder simulator using the glowing material. What he ended up with is quite convincing. Eight segments of EL wire have been mounted between two diverging towers. When a PIR sensor detects motion in the room, an Arduino switches on the simulation, playing a recording of the classic sizzling voltage sound while using the sequencer board to flicker the wires from bottom to top. See for yourself in the video after the break. We give [Paul] bonus points for constructing the base out of Lego.

But if you’re not one for being cautions, there’s always this real Jacob’s Ladder build. Or maybe you just want to make something glow with the EL wire.

Continue reading “Jacob’s Ladder Using EL Wire” →

Using Analog Voltage References With Arduino

December 11, 2010 by Mike Szczys 31 Comments

Little Bird Electronics posted an article about using an analog voltage reference with Arduino. This is a tool available when using an analog-to-digital converter. By setting up either an internal or external AREF, you can better use the ADC considering its resolution limitations. For instance, if you are measuring a signal that you know will always be below 2V, an external circuit, such as a voltage divider or an adjustable regulator, can give you a reference voltage just above that upper limit; say 2.5V. This way the 1024 divisions of resolution will be spread across your signal’s range, rather than just the lower half of the ADC readings.

Analog references are common to microcontrollers that have ADCs. Even if you’re not working with an Arduino, read through the article and use what you learn with your uC of choice.