In a nutshell, the DEFCON 17 badge
is based around a Freescale MC56F8006
16-bit digital signal controller, a Knowles
Acoustics SPM0408LE5H amplified MEMS
microphone, and a Kingbright RGB LED. The
design is meant to be stark, simple, and elegant.
There are very few external components and no
buttons or switches for user interface control.
The only input is the microphone and the only
output is the LED.
The badge operates using a very simple state
machine. Its three modes are determined solely
by the sound level received by the microphone:
• RGB Blend a.k.a., Idle: The LED slowly
blends through a pattern of colors. Occurs
when the sound level is below a pre-defined threshold.
• Color Organ a.k.a., Party: The multicolor
LED changes color and brightness,
depending on audio input volume and
frequency. The LED will “pulse” along to
spoken voice or to the beat of music.
Occurs when the sound level is above a pre-defined
• Sleep: Occurs when the sound level is below a pre-defined threshold for 15 seconds.
All seven badge
styles form the
Two undocumented modes occur when the audio
input meets certain specifications (we’ll disclose those later
in this article).
Other features include multi-badge communication via
a wired interface and a static serial bootloader for in-the-field firmware upgrades. A single CR2032 3V Lithium coin
cell battery provides the required power. The printed circuit
board (PCB) features complicated mechanical outlines,
multiple layers of non-standard silkscreen colors, and a
small 0.1” pitch arrangement of pads that serve as a
prototype area for badge hacking. All components are
mounted on the back of the badge which makes the front
side clean and completely available for artistic elements.
Seven unique badge shapes were used to denote the
types of DEFCON clientele: Human, Goon, Press, Speaker,
Vendor, Contest Organizer, and Uber (awarded to the
winners of official DEFCON contests). Each shape serves as
a puzzle piece and the puzzle can be completed by
placing the seven badges in the correct positions.
D1, MK1, C3,
and BT1 (not
digital converter; two programmable gain amplifiers; three
analog comparators; programmable interval timer; serial
communication interface/UART; real time counter; I2C and
SPI ports; and up to 22 general-purpose I/O lines — all
crammed into a 32-pin LQFP with a 7 mm x 7 mm
footprint. The part supports 1.8V- 3.6V operation, and clock
speeds up to 32 MHz. The DEFCON badge is configured
to run at 8 MHz.
The heart of our badge (U1) is the Freescale
MC56F8006 digital signal controller ( www.freescale.com
which combines the processing power of a digital signal
processor with the functionality and peripherals of a
microcontroller. The MC56F8006 is part of the 56800/E
family and is extremely powerful. It features — among other
things — 16 KB of Flash; 2 KB of RAM;
a six-channel PWM module; 18-channel 12-bit analog-to-
D1 is a Kingbright ( www.kingbrightusa.com)
AAA3528SURKQBDCGKC09 surface-mount RGB LED. This
device features three individual diodes (red, green, and
blue) in a single four-pin, 3. 5 mm x 2. 8 mm package. The
package comes in a rear-mounting configuration which
allowed me to mount the part on the back side of the PCB
and drill a small hole through to the front side for light to
pass. Luminous intensity is 200 mcd, 80 mcd, and 90 mcd
at 20 mA for red, green, and blue, respectively.