1960s Clock Revived with ESP32

Alex Samorukov found a centrally-controlled clock built back in 1960. Atomic clocks were still in their infancy, and the idea of using the Network Time Protocol (NTP) was still many years away. The clock is designed for use in factories, schools, and the like, where everyone internally (even then) needed to be on one coordinated schedule, and utilized a central master clock to actuate each face simultaneously.

To drive the clock, Samorukov adapted an ESP32 dev board with an OLED screen to act as the master device. The clock face is controlled by 12V impulses of different polarities, so he cleverly implemented an L298N DC motor driver to output the impulses as needed. It’s a perfect setup, as the two discreet signals are controlled by transistor logic, and the driver also provides a 5V source to power the ESP32 board.

No real-time clock (RTC) module is used in the setup, as the ESP32 gets time off of the network as a precise NTP source, and the Timezone library taking care of geographic considerations. A special “int” mode allows you to set the clock to 12:00 in order to synchronize the clock’s revolution, and the OLED on the controller features a screen saver mode to save wear and tear on the unit. Code is available on GitHub.