Sluggy Wind Speed Sensor

Sometimes when we look at a hack, its to see how someone chose those parts for the project. In this case, it would have been hard to see it coming. [Janne Jansson] decided to combine a set of measuring cups, a hacked Linksys NSLU2 NAS, and a PS/2 Mouse together to make a self-contained Wind Speed Sensor for his roof. … Read the rest

Motion activated wildlife camera (or a spy device)

Now you can capture pictures of our furry friends by building a motion activated wildlife camera. [Doug Paradis] took his Air Freshener hack and used it to trigger a camera. The white dome in the picture above is the PIR sensor from an Air Wick Freshmatic, along with a cheap keychain camera and an MSP430 microcontroller. He used one … Read the rest

Arduino + Java + Joystick

Interfacing your own hardware with a Java app couldn’t be easier than this example. [Pn] created this proof-of-concept using an Arduino, an analog joystick from a gaming controller, and a few lines of Java code. The Arduino reads an ADC value from the joystick’s x-axis and transmits it over the serial connection ten times a second. The Java program … Read the rest

Playing piano with optical sensors

[Sebastian] is trying to improve the responsiveness of an electric keyboard. He was unsatisfied with the lack of adequate sensitivity to keystroke. The first step in his process was to measure how fast the quickest keystroke actually is. By setting up an LED and phototransistor and taking some measurements he found that sampling at 1 kHz would be more than … Read the rest

Projectile speed sensor

[Mike] built a sensor rig to measure projectile speed. The setup uses a tunnel with two sensors in it. Each consists of a laser diode on one side focused on a photodiode in the other. The two are monitored by an op amp and measured by an ATmega128 microcontroller. When the beams are broken the elapsed time between the … Read the rest

Pressure mapping sensor mat

[imsolidstate] built his own pressure sensitive mat. It utilizes two discs of copper clad board with a piece of foam in between for each of 64 sensors. As the foam gets compressed, the capacitance between the two pieces of copper changes, a measurement that is fairly easy to make with an analog to digital converter. The mat is being used

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Modem used in an alarm system

This alarm system senses motion and then alerts you by phone. [Oscar] had an old external modem sitting around and, with some wise hardware choices, he came up with a simple circuit to use it. First up is the PIC 16F628A chosen because it doesn’t require an external crystal. This connects with the modem via a DS275 RS232 transceiver … Read the rest