In this review we take a look at what is possibly the most fully-featured Arduino compatible board on the market today – the Freetronics EtherMega. This board combines the functionality of an Arduino Mega2560, a microSD card shield, and an Ethernet shield that supports power over Ethernet with optional 802.3af standard. So instead of having these three mashed together at a great expense:
… you can have this:
Which saves space, time and money. Firstly, the specifications:
- 100% compatible with the Arduino Mega2560. So you have the ATmega2560 microcontroller, 54 digital I/O pins with 14 PWM-capable, 256KB of flash memory, 8KB of SRAM and 4KB of EEPROM to play with, the Atmel 16u2 micrcontroller taking care of the USB interface;
- However unlike the original, the EtherMega contains a switchmode power supply that allows operation from a DC power supply of between 7 and 28VDC without overheating;
- Complete c0mpatibility with the Arduino Ethernet shield, using the Wiznet W5100 controller just like the original;
- Network status LEDs on both the socket and the PCB;
- Fixed SPI behaviour on Ethernet chipset;
- Complete microSD card compatibility with SD library, and chip-select is on digital pin 4 so Ethernet and microSD can work together on the same sketch;
- optional 802.3af power over Ethernet support at up to 48V using the optional regulator board which mounts on the EtherMega;
- mini USB connector instead of the larger standard USB socket which can interfere with shields – and a USB cable is included
Furthermore there are a few modifications to make using the EtherMega easier or simpler. The first of these is the onboard prototyping area allowing you to add your own circuitry:
Also notice that the I2C pins have been brought out alongside the 5V and GND pins on the right. The only difference to take note of are the jumpers that are used to select either USB or DC socket power:
However that is a small price to pay compared to the convenience of the wide voltage-handling capability. Finally, unlike the original Arduino Mega2560 the designers have placed the TX/RX indicators at the top-left of the EtherMega so they are still visible when extra shields have been mounted:
The overall design and quality of the EtherMega is top notch, with a thick PCB, rounded corners, descriptive silk-screening, and packaging that can be reused as Mega or other part storage.
If you are looking for an Arduino Mega2560 and could use Ethernet, power-over-Ethernet, a microSD card interface and full, 100% Arduino compatibility you could do a lot worse than getting yourself an EtherMega. If you are interested in learning how to use Arduino and Ethernet – check out our tutorial here. Or to get your Arduino tweeting, visit here.
And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a fourth printing!) “Arduino Workshop”.