In this tutorial, we’ll cover how to get up and running with the SparkFun Ethernet Shield. Requirements, hardware, assembly, and programming will all be covered. Follow along, and your Arduino should be skimming Twitter and hosting webpages in no time!
The SparkFun Ethernet Shield is comprised of two stand-out components - a Wiznet W5100 TCP/IP embedded Ethernet controller and a µSD socket.
The W5100 is a powerful little chip, which implements all sorts of complex network protocols - TCP, UDP, ICMP, IPv4, ARP, IGMP, PPPoE, and the physcial Ethernet layer. This alleviates a lot of programming stress on us and memory stress on the Arduino. All of the communication between the W5100 and the Arduino is SPI-based and handled using the Ethernet library, which we’ll discuss in the firmware section below.
The W5100 is supported by a number of components - capacitors, a crystal, reset monitors - but most especially an Ethernet jack, actually a MagJack. Inside that little RJ-45 jack are a number of transformers and magnetics required for isolating Ethernet signals (you could say this jack is…more than meets the eye). There are even some LEDs poking out the end.
The µSD socket extends near the edge of the shield, where the card should be inserted. The socket sits next to a 74HC4050 (high-to-low level shifter), which handles all of the 5V-to-3.3V voltage shifting (those delicate µSD cards shouldn’t be subjected to 5V signals).
Some of the less spectacular components (don’t tell them I said that) on the Ethernet Shield include a reset button, 3.3V regulator, and a number of blinky LEDs. The reset button works just like the one the Arduino itself, though it’ll also reset the W5100. The LEDs include a power indicator LED, as well as a number of status LEDs (Ethernet receive/transmit, collision, and speed) tied to the W5100, which will appear to have a mind of their own.
위즈네트 칩(W5300, W5200, W7100, W7500) 개발자