Time Server

(last updated: 2009-02-05)

Purpose: The Timer Server is a device that provides time and date information, that is synchronized to the WWVB atomic clock, to devices on an Ethernet network. It is very useful in secure networks that either don't allow, or severly restrict, a connection to the Internet. This project was an entry for the Circuit Cellar "WIZnet iEthernet 2007" design contest - honorable mention award (link). Included as an article in the November 2008 Circuit Cellar Ink magazine (link).

Overview

The NIST radio station near Fort Collins, CO transmits a signal that represent the time and date from an atomic clock. This signal is used by electronic clocks all over the United States to automatically set their time and date. The Time Server receives this signal using the CMAX Time Solutions CME6005 device (with attached antenna). The output of this device is a stream of pulses that represent the time and date. The pulses are decoded by a Freescale MC9S08QG8 microcontroller. The microcontroller runs a local real-time clock, and this clock is synchronized to the WWVB time whenever the time code signal is decoded. The interface to the Ethernet is managed using the WIZnet W5100. The W5100 manages Ethernet transactions up to the TCP/IP level, and the microcontroller takes care of the SNTP, TIME, and DAYTIME protocols.

The hardware for this project is suitable for a first-level prototype. It uses module boards for CMAX's CME6005, Freescale MC9S08QG8, and WIZnet W5100. The software found here is also first-level prototype; though production-level code is available through special arrangement.

Download (see Attachments):

TimeServer_doc.doc - hardware and software design description

TimeServer_code.zip - project files for the IAR EWARM C compiler/IDE/debugger; (as submitted for contest)

Note: An even more recent version of the Timer Server code is available that includes robustness features and error handling. This version is not freely available since it is production ready, so it has significant value. Any party interested in working out an agreement per the Terms of Use may contact me.

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