2R Hardware & Electronics: Arduino Ethernet Shield with PoE Module

Wednesday, December 02, 2015

Arduino Ethernet Shield with PoE Module

Shield Arduino ethernet latest version of the module that has been integrated PoE (power-over-Ethernet). Based Wiznet W5500 ethernet chip which has the ability to interface ethernet with TCP and UDP protocols include internal 32K buffer. PoE module allows Arduino shield along to be able to operate in standalone utilizing active Ethernet data path as its power supply. Additional features of the shield is the presence of a micro-SD slot which can be used for file storage that can be accessed via ethernet. Ethernet library already included in the Arduino IDE so it will be very easy to start using.

It also includes a reset controller, to ensure that the W5100 Ethernet module is properly reset on power-up. Previous revisions of the shield were not compatible with the Mega and need to be manually reset after power-up. The reset button on the shield resets both the W5100 and the Arduino board.

Arduino communicates with both the W5100 and SD card using the SPI bus (through the ICSP header). This is on digital pins 11, 12, and 13 on the Duemilanove and pins 50, 51, and 52 on the Mega. On both boards, pin 10 is used to select the W5100 and pin 4 for the SD card. These pins cannot be used for general i/o. On the Mega, the hardware SS pin, 53, is not used to select either the W5100 or the SD card, but it must be kept as an output or the SPI interface won’t work.

Note that because the W5100 and SD card share the SPI bus, only one can be active at a time. If you are using both peripherals in your program, this should be taken care of by the corresponding libraries. If you’re not using one of the peripherals in your program, however, you’ll need to explicitly deselect it. To do this with the SD card, set pin 4 as an output and write a high to it. For the W5100, set digital pin 10 as a high output.