Honorable Mention #6
The well-designed Time Server keeps a master time and date clock that is synchronized to the U.S. WWVB time-code signal. It exists on the Ethernet network and serves time and date information according to the SNTP, DAYTIME, and TIME protocols. Client devices can connect to the system, request the time/date, and synchronize their local clocks. Because the Time Server doesn’t rely on Internet servers, it can be used in secure networks that aren’t connected to the Internet. A WIZnet W5100 provides the interface to the Ethernet network. A Freescale MC9S08QG8 microcontroller is used to decode the time-code pulse stream, update a real-time clock, and serve time/date information to clients on the Ethernet network.
“The Time Server is a fixed-function node on an Ethernet network that provides time and date information referenced from the NIST WWVB time-code radio signal. Once I developed the interface code that set up a socket connection, using the W5100 was very simple. I especially liked that I didn’t have to compile a huge Ethernet stack. The SPI interface was especially important in the Time Server design since I wanted to use a microcontroller with a low pin count. Additionally, since the TCP/IP stack is embedded in the W5100, I don’t have to worry about code integration issues, large flash and SRAM requirements, or license and royalty costs.”—Steven Nickels