Small and colorful, Cipherling is a gadget designed for radio enthusiasts. Using a Wi-Fi internet connection, this mini robot can pick up number stations scattered around the world and play their transmissions.

Number stations are encrypted radio broadcasts that have fascinated amateur radio operators, historians, and espionage enthusiasts for decades. Their operation is both simple and mysterious: a synthetic or human voice recites long strings of numbers, letters, or sounds, often accompanied by musical cues. 

These messages—whose meanings remain indecipherable without the correct key—are believed to have been used by governments to communicate with field agents as far back as World War I. During the Cold War, their mystery fueled theories and speculation, but even today, some of these transmissions continue to be detected on radio frequencies, preserving their cryptic allure.

Cipherling features a 3D-printed shell and is powered by an ESP32-based motherboard that controls a small color display, an audio amplifier, and a green LED. On its side, a knob allows users to turn the audio feed on and off or adjust the volume when rotated. The device stands on three small metal legs equipped with rubberized, non-slip feet, and it is powered via a USB-C connector on the back.

As for its functionality, Cipherling updates its feed by receiving information from a remote receiver installed in the United Kingdom. When a radio transmission is detected, the robot signals it with an audio ping and a flashing green LED. Pressing the designated knob starts live playback of the feed. The display provides details about the transmission, such as its origin or the type of code being used. Some broadcasts are encoded in binary, others in Morse code, and some may simply consist of noises that—though seemingly meaningless—likely carry a precise meaning for someone.

Not yet available for purchase, Cipherling was introduced through a crowdfunding campaign on Kickstarter, which successfully reached its goal

Opening image: Tim Burrell-Saward, Cipherling, 2025. Courtesy Tim Burrell-Saward e Kickstarter