About the ElectroKev Atomic Clock. (EACP)

This document assumes a foundational understanding of electronics, programming in various languages, horology, and basic mathematical principles.

The EACP (ElectroKev Atomic Clock Project) incorporates an electronic quartz module similar to those found in standard watches and clocks. A conventional quartz crystal oscillates at 32,768 Hz when electrically stimulated, enabling a binary counter to efficiently divide the frequency down to 1 Hz through 15 stages of division. These crystals typically exhibit an accuracy of ±15 parts per million (ppm), resulting in a drift of approximately 15 seconds per month in standard-grade units.

Quartz oscillators are inherently temperature-sensitive, with frequency decreasing in cooler conditions. Standard watch-grade crystals are calibrated for minimal drift at 25°C and are generally used within a -40°C to +40°C range. However, at -40°C, the frequency can drop to 32,766 Hz, leading to a time loss of approximately 4.8 seconds per day.

In contrast, atomic clocks employ high-precision frequency standards such as cesium or rubidium oscillators, which minimise drift over thousands or even millions of years. The EACP utilises a high-stability 10 MHz oven-controlled crystal oscillator (OCXO) to ensure frequency consistency, irrespective of environmental fluctuations. 

The OCXO generates a stable square wave, with built-in circuitry designed to minimise interference and frequency fluctuations through advanced filtering and shielding techniques. Additionally, a dedicated filtered and regulated power supply mitigates potential instabilities caused by power variations.

The 10 MHz output from the OCXO is processed through a series of six 74LS90 integrated circuits, which function as frequency dividers. Each 74LS90 is a decade counter composed of a 4-bit ripple counter, capable of dividing a signal first by 2 and then by 5, effectively achieving a divide-by-10 operation. By cascading six of these ICs, the frequency is progressively reduced to 10 Hz, which is then fed into the GPIO of an ESP32 Dual-Core Microcontroller for further processing.

The ESP32 is a powerful dual-core microcontroller developed by Espressif Systems, featuring built-in Wi-Fi and Bluetooth connectivity. It is based on a Xtensa 32-bit LX6 processor, with clock speeds up to 240 MHz, making it well-suited for high-performance IoT applications. The ESP32 includes multiple GPIOs, analog and digital interfaces, PWM, SPI, I2C, UART, and DACs, providing flexibility for various projects. It supports FreeRTOS, allowing multitasking and efficient resource management. 

The ElectroKev Atomic Clock Project is designed to achieve exceptional timekeeping accuracy with the following objectives:

• Maintain a level of precision surpassing that of conventional electronic clocks.

• Represent time in standardised formats recognised by established technology protocols.

• Provide external public access to accurate time through widely adopted synchronisation methods.

• Continuously reference Stratum 1 clocks to monitor and quantify drift.

• Implement an independent drift compensation mechanism that operates without reliance on external time sources.