Archive for May, 2015

Network cable tester

Build a network cable tester with just two cheap integrated circuits and a few parts from the ‘junkbox’.
This cable tester, tests all the 8 wires in a network cable in one move, if one of the 8 LEDs does not lit up, it means that the wire corresponding to that LED is faulty.

You need:

  • 1 x 4017 decade counter,
  • 1 x 555 timer,
  • 8 x LEDs,
  • 2 x 8P8C modular connector (RJ45),
  • 8 x 100Ω resistor,
  • 1 x 10KΩ resistor,
  • 1 x 15KΩ resistor,
  • 1 x 4,7µF capacitor.

network-tester

The yellow LED has no special significance, I only had 7 green LEDs.

CSS propeller

Just for fun!

See demo CSS3 Keyframe Animation Propeller

<html>
  <head>
    <title>CSS3 Propeller</title>
  </head>
  <body>
    <div class="propeller"></div>
  </body>
</html>
.propeller {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  margin: auto;
  
  width: 0px;
  height: 0px;
  border-width: 200px;
  border-style: solid;
  border-color: #fff #00f #fff #00f;
  border-radius: 50%;

  -webkit-animation-duration: 0.2s;
  -moz-animation-duration: 0.2s;
  -o-animation-duration: 0.2s;
  animation-duration: 0.2s;

  -webkit-animation-name: rotateCircle;
  -moz-animation-name: rotateCircle;
  -o-animation-name: rotateCircle;
  animation-name: rotateCircle;

  -webkit-animation-iteration-count: infinite;
  -moz-animation-iteration-count: infinite;
  -o-animation-iteration-count: infinite;
  animation-iteration-count: infinite;

  -webkit-animation-timing-function: linear;
  -moz-animation-timing-function: linear;
  -o-animation-timing-function: linear;
  animation-timing-function: linear;
}

@-webkit-keyframes rotateCircle {
  from {
    transform: rotate(0deg); 
  }

  to {
    transform: rotate(360deg);
  }
}

@-moz-keyframes rotateCircle {
  from {
    transform: rotate(0deg); 
  }

  to {
    transform: rotate(360deg);
  }
}

@-o-keyframes rotateCircle {
  from {
    transform: rotate(0deg); 
  }

  to {
    transform: rotate(360deg);
  }
}

@keyframes rotateCircle {
  from {
    transform: rotate(0deg); 
  }

  to {
    transform: rotate(360deg);
  }
}

More on CSS animations you can find here:
https://developer.mozilla.org/en-US/docs/Web/CSS/animation
https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Using_CSS_animations
https://css-tricks.com/almanac/properties/a/animation
https://css-tricks.com/snippets/css/keyframe-animation-syntax