Invisible WiFi made Visible


WiFi is all around us, the connections made by devices as MAC addresses can be monitored, as can the data itself and also  the density of the signals. The aim of my project is to render one or more of these varying things  as an array of self lit cubes. I will be using ESP8266 or similar to detect WiFi data and if possible, extend the concept to mapping out a large space to convert signal strength of WiFi signal sources.


I have already prototyped the ESP8266 to get the MAC addresses into Arduino IDE serial monitor,using a library developed by Ray Burnette to get a serial stream of Media Access Control (MAC) addresses. These will appear and disappear as mobile phones, laptops enter and leave the space. First 6 digits of the MAC address shows the manufacturer, I will research what else I can derive from the MAC address. More recent iPhones obfuscate their identity by throwing up fake MAC addresses periodically as the ping the WiFi. This could be identified in the installation.

The ESP 8266 will have a serial connection to an Arduin which in turn parses the data coming across so that it can communicatewith an Adafruit 16 channel servo shield. By parsing the serial data sent by the the ESP8266, Arduino will  provide the necessary cues for the operation of the physical installation (the grid of flip up doors), communicating with controlling arduino(s) via a serial bus.

Rendering is a part of the project I have yet to consider but I would want more than just showing LEDs or LCD panel, monitor etc.

It is proposed that a 5 x 3 grid of PLA 3d printed cubes laid out inside a flat MDF laser cut frame will contain the electronics and a small LCD screen to plot the progress of data.  When a new MAC address appears, one of the cubes pops up and the LED will light up. As more connections are made on any particular channel, the resspective cube will move in and out accordingly.

I will build a prototype to show a single cube in action.

Initial sketch:

layout for top of case


Lasercutting plan for case



preliminary Frizing (to be updated)


OpenSCAD Sketch of simple mechanism fot moving cubes off servo



Servo arm may well be just wire connecting to (3d printed) red cube yellow cylinder attached to cube may be same as red cube part. Yellow servo isattached to base, lying on its side. Another printed part to be used to hold servo. See Appendix for my Thingiverse part I created some time ago.

Statistics can also be shown on a small Nokia 5110 LCD in any case to monitor progress, alternatively out to a led 7 segment numeric display.

Power to be supplied via 5v phone charger. The servos may need an independent power supply, yet to be determined.

Further ideas:

Data logging to SD card (MAC adresses, visitors and time in and out).

Integrate with other devices, e.g.  TC35 SMS module to send tweets to twitter…

As well as using Fritzing to design the breadboard layout and the layout for the soldered components, I will use OpenSCad to design the 3D printed components and Tinkercad or for the main MDF enclosure.

References: Expressif/Arduino-esp32

@Igrr IvanGrokhotkov (

The Glass Room Exhibit Oct-Nov 2017

“Unintended Emissions
Julian Oliver & Bengt Sjölén & Danja Vasiliev
The Critical Engineering Working Group
@julianOliver / @bengtsjolen / @k0a1a

As you make your way around the city each day you are constantly emitting data from your devices and being filmed on CCTV. As you stand here, The Critical Engineering Working Group is using radio receiver–like technology to passively scan the exterior pavement for signals from passing devices. Those signals are then being shown to pedestrians passing by The Glass Room in real time. The devices shown live on the screen are detected and located by ‘unintended electromagnetic emissions’, otherwise known as ‘data transmissions’. They are then represented here, creating a kind of livestream of data passing by.”

TFLto track customers MAC addresses

“The trial, which will last four weeks from 21 November, “will help give TfL a more accurate understanding of how people move through stations, interchange between services and how crowding develops,” according to the transport authority.”

Servo holder stl I uploaded a while ago…

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