11

FIELD TEST

dding lots of LEDs in a
Charlieplexed arrangement is fairly
simple, though a little tedious,
when you are using through-hole
components like 5 mm LEDs.
But what happens when you want
those LEDs to be really small and packed together
so you can create a higher-resolution display? That’s
where the LED Charlieplexed Matrix comes in handy.
We can’t imagine soldering all those LEDs in place,
especially when they are that close together.
To control this many LEDs effectively, you need
a backpack, or a breakout board like Adafruit’s 16×9
Charlieplexed PWM LED Matrix Driver. Although this
matrix needs another driver board to work, it’s well
worth the additional hardware. Once connected,
you have complete control over each individual LED,
including its brightness, which is not something you
see that often in a Charlieplexing array. This allows for
some smooth animations and effects. The LED array
is available in six colours, and Adafruit has a great
tutorial including code examples and more!

A

CHARLIEPLEXED $6.95 adafruit.com

SPARKFUN $8.95 sparkfun.com

LED Charlieplexed Matrix

vs SparkFun LED Array – 8×7

Making LED grids easy to control

LED

Charlieplexed

Matrix

Great price, but

be aware that it

needs a

driver board.

SparkFun

LED Array

You can control

all 56 LEDs with

only eight pins.

9

8

/ 10

/ 10

VERDICT

he SparkFun LED Array is a set of 56

red LEDs arranged in a nice

8×7 grid. This little board requires

eight pins, while the library supports

any ATmega168- or 328-based Arduino

device. The SparkFun LED Array

was developed to be used in conjunction with the

BadgerStick as a fun and interactive way for people

to learn about soldering, and engage with SparkFun

products at the multiple trade shows they appeared

at. Now this array is available to everyone!

The SparkFun LED Array relies on the

Charlieplexing to control individual LEDs. This is a

very popular technique that allows you to control all

56 LEDs with just eight pins of your microcontroller.

The layout of the board makes it a perfect addition

to the BadgerStick, now known as the SparkFun

RedStick. As mentioned, SparkFun has developed

a library for the array, supporting both ATmega168-

and 328-based Arduino platforms, making it easy to

implement into your next project.

T

Left

56 LEDs neatly

organized in an

8×7 grid

Below

144 LEDs. What’s not

to love?