Two shared wires
SDA and SCL form an I²C bus. Multiple devices can share those two lines because each device is identified by an address. A connector can therefore carry both power and a conversation.
Reference 01
International Morse code
Morse represents letters, numbers, punctuation, and control signals with groups of short and long signals. The signal might be heard, seen, or simply timed; the spacing between groups matters too.
A
·—B
—···C
—·—·D
—··E
·F
··—·G
——·H
····I
··J
·———K
—·—L
·—··M
——N
—·O
———P
·——·Q
——·—R
·—·S
···T
—U
··—V
···—W
·——X
—··—Y
—·——Z
——··1
·————2
··———3
···——4
····—5
·····6
—····7
——···8
———··9
————·0
—————Punctuation & control signals
.
·—·—·—Start of message
—·—·—,
——··——?
··——··Standard timing
Dot1 unit
Dash3 units
Inside a letter1-unit gap
Between letters3-unit gap
Between words7-unit gap
Pattern note: a pause can carry as much information as a pulse. A repeated sequence is usually easiest to separate at its longest pause.
Reference 02
The SAO connector
The badge includes a six-pin SAO-style connector. SAOs—often called Simple Add-Ons—can be decorations, electronic accessories, or small devices that exchange data with a badge.
3V3
SDA
GPIO1
GND
SCL
GPIO2
Red marks the 3V3 / pin-one side. Follow the badge silkscreen.
What the labels mean
- 3V3
- 3.3-volt power supplied by the badge.
- GND
- The common electrical reference.
- SDA
- The data line commonly used by I²C devices.
- SCL
- The clock line commonly used by I²C devices.
- GPIO1/2
- General-purpose signal pins; behavior depends on the badge and add-on.
Before connecting anything: power the badge off, match 3V3 and GND, and never feed 5V into the connector. Some 2×3 plugs can physically fit backward.
Orientation matters
“Top view” and “bottom view” mirror each other. Trust the printed labels and the 3V3 marker on the actual boards—not the direction that looks convenient.
Reference 03
Light, distance & base stations
Electronic devices can communicate with light outside the range people can see. Infrared—IR for short—is common in remote controls, sensors, and short-range links.
Invisible does not mean inactive
IR emitters often look dark to the eye. Many phone cameras can see them as a faint white or purple flicker, although some cameras filter IR more strongly than others.
Line of sight matters
Distance, angle, bright sunlight, reflective surfaces, and objects between two devices can all change how reliably an optical signal is received.
The end of a badge containing the emitter or receiver generally works best when it has a clear view of the station target.
A change in light or sound can acknowledge a signal. Some stations also need a short moment before they are ready again.
If something seems offline, ask event staff for help rather than unplugging, moving, or resetting the station.
Reference 04
Small nudges
Open only if useful. These are observations, not instructions.
About the artwork and labels
On a purpose-built circuit board, silkscreen labels, symbols, arrows, component placement, and unusual empty space may all be part of the documentation.
About short and long signals
A light can express the same short–long pattern as a buzzer. “On” and “off” time both contribute to the rhythm.
About the six-pin port
Power is only two of its six connections. Four pins remain—and two of those form a bus designed for addressed devices.
About the base stations
A station may be listening even when it appears idle. Alignment, timing, and a clean line of sight are usually more important than force or repetition.