Design with Mcus

20 March 11 Electronics World ETHERNET IS, BY FAR, the leading wired standard for networking as it enables to connect a very large number of computers, microcontrollers and other computer-based equipment to each other. Ethernet allows devices and equipment to be accessed remotely and provides a cost-effective and reliable means of monitoring or controlling such equipment. Ethernet has traditionally been implemented on PCs and laptops and has been used widely at home, office and industry to access the worldwide Internet and company-wide intranet networks. Internet can nowadays also be accessed using low-cost portable electronic gadgets such as smart mobile phones, PDAs and others. With recent advances in technology and especially in chip manufacturing, Ethernet can now be fully realized through single-chip devices. Several manufacturers offer either single-chip Ethernet controllers, or general purpose microcontrollers with on-board Ethernet controllers. Such controllers can very easily be configured, programmed and used in Ethernetbased embedded applications. Typical applications of embedded Ethernet include: Home automation Access control Environmental monitoring Industrial control Safety and security POS terminals Remote control Lighting control. PIC18F97J60 is an advanced microcontroller chip manufactured by Microchip Inc (www.microchip.com) with built-in 10Base-T Ethernet capability. The device offers 128K flash program memory, 3908 bytes of RAM memory, 70 I/O pins, 16 10-bit A/D channels, timers, counters and many more features. Microchip’s ENC28J60 is a popular 28-pin serial Ethernet chip that can easily be used in microcontroller-based applications to provide Ethernet capability to the application. Several manufacturers offer Ethernet development kits, enabling users to learn and incorporate Ethernet functionalities in their designs. Examples of some development kits are: ETHERNETDK (www.silabs.com) is an Ethernet development kit that provides all the necessary hardware and software to create real-time embedded Ethernet-based applications. The kit contains an 8051 microcontroller-based C8051F120 microcontroller and a CP2200 Ethernet chip with an RJ45 connector. A Silicon Laboratories evaluation kit and application examples are provided on a CDROM distributed with the kit. PIC-MINI-WEB (www.olimex.com) is an embedded Ethernet development board using a PIC18F25J10 chip as the microcontroller and an ENC28J60 Ethernet chip. 1Mbit on board serial flash memory is provided to store web pages. In addition, a mini ICSP/ICD is available on the board for programming and debugging. The Embedded Ethernet Development kit manufactured by CCS (www.ccsinfo.com) is a complete kit based on the PIC18F4620 microcontroller and the ENC28J60 Ethernet chip. The kit provides 30 I/O pins, one potentiometer, LEDs, serial EEPROM, an MMC card reader and RJ45 socket. The development kit is supported by company’s IDE, including a compiler and in-circuit real-time debugging tool. The Serial Ethernet Board manufactured by mikroElektronika (www.mikroe.com) is based on the ENC28J60 Ethernet chip and it can easily be connected to company’s development boards (EasyPIC5 or EasyPIC6). The board is fully supported by mikroElektronika C, Pascal and Basic compilers. This article describes the details of the ENC28J60 Ethernet chip and shows how the chip can be used in a simple microcontroller-based networked home automation system to turn lights ON and OFF.