This old-school telegraph sounder can tap out tweets

This project connects 19th century technology with today’s cellular networks.

Long distance telegraphy first appeared back in 1792 in the form of semaphore lines, which sent messages to a distant observer through line-of-sight signals. Commercial electrical telegraphs were later introduced in 1837. These devices were physically connected by wires between stations, and operators tapped out messages in Morse code on a small, paddle-like device called a key.


Fast forward 178 years and one Maker is breathing new life into the old-fashioned mechanism. Devon Elliot recently outfitted an old telegraph sounder seated in a wooden resonator with some modern-day electronics so that it could tap out tweets.

“This project was an attempt to connect technology rooted in the 19th- and early 20th-centuries with 21st-century networks,” Elliot writes. “The results bridge those time periods through the technologies used. The telegraph sounder was used as the starting point and is the output of the device.”


To start, the Maker connected an Arduino Uno (ATmega328) to the machine, which was tasked with controlling the sounder by triggering the coils — turning them on and off via one of the board’s digital I/O ports. Elliot used the Arduinomorse library to translate messages into Morse code and activate the sounder. Meanwhile, a handful of other components including a resistor, diode, and transistor were added to protect the digital pin of the Arduino by separating the activation signals from the powering of the coils.

The other main component is a FONA board. This device from Adafruit is an all-in-one cellular phone module that enables Makers to add voice, text, SMS and data to projects in an adorable little package. In this case, Elliot connected the FONA to the Arduino, and programmed the ATmega328 based board to check for SMS messages periodically. If an inbox message was found, it would then translate it into Morse code and tap them out on the sounder.


Rounding out the design, the Maker mounted the electronics onto a piece of black acrylic and attached it to telegraph. “This was convenient as nothing had to be permanently altered to the historic device. Wires were attached to it via the provided screw terminals, so those can be detached and the base unscrewed to remove the electronics,” he adds.

Upon completion, Elliot was left with a standalone telegraph sounder that was not only connected to cellular phone networks, but equipped to receive SMS messages and tap them out in Morse code. The modded device can operate off batteries if necessary, allowing it to work anywhere with cell reception. The machine’s cellphone number is paired with a Twitter account, which was also set up to send an SMS to that number whenever the account is mentioned. If you’d like to activate the telegraph with a Twitter message, go ahead and tweet @ldntelegraphco.

Interested? Head over to the project’s official page here. If you enjoyed this retrofitted device, you may also want to check out this 1930s typewriter social networking machine.

1 thought on “This old-school telegraph sounder can tap out tweets

  1. Pingback: Here are some unbelievable projects to help celebrate Arduino Day | Bits & Pieces from the Embedded Design World

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