資料來源：https://www.seeedstudio.com/Seeeduino-V4.2-p-2517.html

Description
Seeeduino V4.2 is an Arduino-compatible board, which is based on ATmga328P MCU. There're so many Arduinos and Arduino-compatible boards in the world, and we think that Seeeduino V4.2 is one of the best Arduinos, Seeeduino V4.2 is much more stable, easy-to-use and even good looking.

Seeeduino V4.2 is based the Arduino UNO bootloader, and with an ATMEGA16U2 as a Uart-to-USB converter, which means that the board can basically work like a FTDI chip. You can program the board via a micro-USB cable, if you have an Android phone, you can find a micro-ISB cable easily. Also you can power the board via a DC Jack input, 7 to 15V is acceptable. There's a switch to choose the system supply voltage, 3.3V or 5V, which is very useful if you want to set the system to 3.3V to save power.

Finally, the three on-board Grove interface can make your board connect to Groves easily. Want to make something awesome, maybe just a Seeeduino V4.2 and some Groves is enough. 

Features

ATmega328P microcontroller

Arduino UNO bootloader

14 Digital I/O Pins (6 PWM outputs)

6 Analog Inputs

ISP Header

Arduino UNO-R3 Shield Compatible

Micro USB programming and power supply

3 on-board Grove connectors

3.3/5V system operation power switch

Seeed Fusion has launched special offer for Duino customize service for over 1000 units. It is only $6900 in total for 1000 units Duino (you can design your own logo on Seeedunio). If you are interested in our special offer or have more questions regarding this service, please contact us at [email protected].  

Technical Details
Dimensions    115mm x 78mm x 25mm
Weight    G.W 41g    
Battery    Exclude
3 on-board Grove connectors
DC Current per I/O Pin    40 mA
DC Jack Input    7v-12v
Flash Memory    32 KB
RAM    2 KB
EEPROM    1 KB
Clock Speed    16 MHz
Part List
Seeeduino V4.2    1
Documents
Seeeduino V4.2 in EAGLE file
Seeeduino V4.2 in PDF
ATmega328P
ATmega16U2
Learn

[Wiki]Seeeduino V4.2
Seeeduino v4.2 is an Open Source, Arduino-compatible ATmega328 MCU development board. We think Seeeduino v4.2 is one of the best Arduino derivatives/compatibles available. Seeeduino v4.2 is feature rich, much more stable, easy-to-use and even good looking