Posts Tagged ‘LED’


Ping Pong Balls & Electronics

December 21, 2011

Working on a sign for my fortune teller project.  I had forgotten how great ping pong balls with LEDs inside them look.

These will go on top of the actual sign which will be oval shaped.

I like this idea so much i may make another sign for my work area.
I wonder what other uses ping pong balls have in electronics?


New Project – Glowing Recharging Table

September 8, 2011

My next project is a table that glows at night.

I plan to use a photoresistor and about 25 LEDs.

I will need to use a transistor and another power supply for the LEDs, along with the Arduino as the brain. I will connect them to the PWM pins on the Arduino to control how bright they are. 4 LEDs draw too much current for an Arduino pin, so I need the transistor and another power source.  Each Arduino can handle 40 mA of current and each LED has 20 mA of current.

In the photos here I was testing the transistor and LED setup.  I am using 2 2n222 transistors with 4 yellow 20 mA 2.0 V LED’s connected to each transistor. Each LED has a 100 ohm resistor connecting it to the voltage.

Here is some simple test code.  LED Test.

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Purse LED

June 16, 2011

Purse SwitchLast year I had an idea to put an LED inside a purse so you could see inside it at night.

I had a lot of help from the Adafruit forums and ended up with a cool little circuit.

The main idea being you would solder one wire to each side of some magnetic snaps.

The circuit would be closed and turn the light off when the snaps were locked together.  The two wires going off to the left would be soldered onto the snaps.

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