WWVB Clock Built on PIC16F628 Microcontroller

Overview

The project utilizes a PIC16F628 microcontroller in order to create radio controlled clock that originates from NIST Radio Station WWVB that broadcasts on a frequency of 60kHz.

Details

The time display can be seen in 12-hour format with 6-digit display of hours, minutes, and seconds using 1” 7-segment LED displays. It auto synchronizes the internal time with WWVB time and employs a WWVB sync indicator. It receives broadcast from WWVB and maintains local time when WWVB signal is lost. For Daylight Savings Time, it performs auto detects/corrects as this version is for Pacific Standard Time. C language is used to write the software since all the tools are available for download on the web for free. For both receiver samplingand internal time propagation, 32 interrupts/sec is set to be provided.

The decoded time data is sequentially outputted from the PIC16F628 microcontroller running at 4MHz to the 7-segment decoder/driver on a 4-bit data bus. The data is outputted sequentially as seconds, 10s of seconds, minutes, 10s of minutes, hours, and 10s of hours. To save cost of two separate boards, the design contains the main board and the display board on a single layout.