Meccano model of the Chappe semaphore controlled by Arduino 

I have constructed a model of the Chappe optical telegraph that was used between 1793 and 1850. The Chappe system consists of masts that are mounted on towers, between 10 and 15 kilometres apart. On top of the mast is a moveable crossbar with two arms. The positions of the crossbar and arms represent a symbol or a code. My Meccano model simulates the operation of a Chappe mast. The model uses three small servomotors. These motors are controlled by a Wemos board, programmed in Arduino code. The message to be transmitted can be sent by WiFi from a computer or smartphone.