Embedded server and client system for home appliances on real-time operating system

Abstract

This paper proposes a small, power saving embedded Web server for home appliances. The proposed device operates with a real-time operating system on a 32 bit RISC microprocessor. A TCP/IP protocol stack, HTTP, FTP, SNTP server and client applications were developed. The prototype server requires one fortieth the power of a general server using a PC. The software resources are about 1.8 MB. Demonstrations of general Web services and functional tests of remote manipulation via the Internet were conducted to verify the prototype system. The verification results showed the texts and images stored in the server were displayed dynamically without stress. The operation of remote controlling the server through a PC connected with a LAN was also confirmed to be stable. Therefore, the proposed Web server can be easily implemented into home appliances, which require space saving, power saving and low price.

Development of Embedded Simple Network Time Protocol Client Clock

“…Moreover, SNTP operates well with other protocols such as HTTP, FTP, Home Network Protocol, and can be implemented on embedded system. Nonaka, et al [4] presents using of SNTP with other protocols for home automation and RTOS (Real-Time Operation System). They show that, the sensor of system can request time from their proposed SNTP system directly which is very convenient.…”

“…Drift time = (1,000,000 x Required Accuracy (second))/frequency tolerance (3) Drift rate = (frequency tolerance/1,000,000) x 100 (4) By this information, we can calculate the drift time of clock as 50,000 seconds. I.e., as time goes by 50,000 seconds (13 hours, 53 minutes, 20 seconds), the time of embedded SNTP client clock will drift by ±1 second or the drift rate is 0.002% per second.…”