Wednesday, September 14, 2011

Mini projects II

5 LEDs ready to shine

When you don't have time to do a real project you make up one. While doing some microcontroller tests I was using four separate LEDs. This was a bit messy with all the current limiting resistors. What would be better would be a small set of LEDs with resistors in one handy single block.

Ideally I wanted to use a SIL resistor array but didn't have anyone selling them locally (Little Bird Electronics now do). So it was going to be individual resistors and 3mm LEDs and some tight soldering. Also I wanted long header pins but no luck. Of course 3 days after I had finished Little Bird Electronics started selling long header pins.

My breadboard has two rows of holes above and below the normal breadboard area (ie for power rails). These power rail blocks have five hole groupings (instead of a continuous row of holes) so my LED stack would be five pins wide. That way I could plug in the block of LEDs into either the positive or ground rail depending on the circuit. As I am normally running 5 volts on my breadboard I used ?? resistors to limit the current to the LEDs.

The base for the project was a cut down piece of prototype board. Some tight soldering of header pins, LED, resistors and everything was done. I also had to file down the solder on the LED and resistor pins as the normal size header pins meant there wasn't much room underneath to ensure a good fit into the breadboard. Now the 5 bit loving can began.

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