2×2 LED matrix


Breadboard layout for the 2×2 matrix with rows and cols labelled
Laid the circuit out on a cardboard simulation of the breadboard, with wires taking the place of the breadboard rows and columns.
It’s unorthodox, but it helped me to do this to see the flow of the current. I tried to do it from the breadboard, but it was a bit easier for me to understand when I could move the wires around a bit.
I also really like the look of the wires and the components in this “soft” circuit. I guess this could be a really funky sewable electronics project if we wanted it to be!

(above) Finally able to decipher what it did, and got Joe the Bro to help explain it.

Note: the 2N2222 transistor is a NPN (not pointing in) BJT (bipolar junction transistor). Collector is negative, base is positive, emitter is negative. Technically, the flow of current is from positive to negative in a diode, but the application of a current to the base AND a current being applied to the collector will enable saturation of the middle layer of the transistor sandwich and permit flow from the collector to the emitter.

Circuit explained.

The two transistors are acting as switches.  A voltage applied to the base  will cause the base layer to become saturated with electrons and cause the current to flow from the collector to the emitter .  This permits a flow of the current through the 2 LEDs connected to each transistor.

Unplugging one of the transistor bases will prevent the related collector-emitter flow, and will turn off those LEDs attached to the transistor.

Disconnecting the wires attached to either of the 220 ohm resistors will break the circuit for the two LEDs connected to that resistor.

Next up: add 4 single input, single output switches on each of the resistors.

Long Beach AFOL – February 2013

Our first meeting of the Long Beach AFOL will be on Wednesday, February 27th, 2013 at the Cultural Alliance, 727 Pine Street.  6:45 to 8:00.

Adults are welcome to bring one child.

Danny Tsoi-A-Sue will present his personal creations, many of which are military style vehicles and take inspiration from actual military models.

Trish Tsoiasue will share the opportunities provided by the Hailfire Droid gear, possibly the largest LEGO piece ever made.

How do you Sort Your LEGO?

LEGO comes in hundreds, possibly thousands of shapes, and you could probably say the same of its colors!  For most builders it suffices to have one – or several – giant tubs.  If a specific part is needed, the builder will rake through the tubs, one by one, searching for that perfect LEGO part.

The basic brick shapes and colors are 2×2 and 2×4 bricks bright yellow, blue, red, green – but there are so many colors and shapes beyond that!  Delicious Easter greens, pinks, yellows that appeal to the girl in us.  Shades of sand and grey for walls.

I’ve had a personal preference for the educational benefit of LEGO, and have gathered many, many LEGO Technics parts: beams, pins, gears, gearboxes, motors of various kinds.  As of yesterday, my sorting was by shape.  All LEGO rounded beams in one drawer of the caddy specially purchased for LEGO. All LEGO pins and axles in another, Squared LEGO beams in another, gears separated out.

Today, I’m thinking about LEGO for design.  This is what most folks who use LEGO see in it.  The potential for a myriad of designs in all of those colors! So today, I turn my sort to the non-technics bricks that have remained in the bins.

I’m specifically thinking about Valentines day designs, and I’m seeking the color red.  But while I do this, I’m thinking about the potential for designs within designs, and for that I need more colors.

So, I’m sorting my LEGO bricks… the non-technics varieties… by color.

It’s truly a sight to see so many red bricks stacked together!  All different shapes bunched together, the only distinction is the color.  Reds in one pile, blues in another, regardless of shape.  Car hoods and sloped bricks, 1x1s, 2x2s and 2x4s all in the same pile.

A variation – I’m thinking that I will put all translucent bricks together (regardless of color) and that I will put all 1×1 and 1×2 plates together, as they will have a special purpose.. that of creating the designs within designs.  The 1×1 and 1×2 plates are tiny enough to let you create shapes, and curves, without taking up too much space.

It’s a very personal thing, the LEGO sort system.  I don’t think that anyone will ever have the perfect system.

Do you have the perfect system?  How do you sort your LEGO?