Use Atmel Atmega328P-AU singlechip
With 14 digital input/output port RX， TX， D2~D13 (6 for PWM output)
8 analog input A0~A7， ATmega328 running at 16MHz with external resonator
1 pair TTL receive and transmission port RX / TX
6 PWM port: D3， D5， D6， D9， D10， D11
Uart download file
DC input 3.3~12V
9V Battery

Frequently Asked Questions:
Q1. Why are these called "Arduino Compatible"?
A1. The Arduino group demanded us to remove their logos and rename these products so that they do not lead customers to believe they are the same units sold by Arduino
Q2. Are these 100% compatible with the "normal" Arduino's?
A2. Yes， they really are completely compatible with "normal" Arduino's. Build quality looks the same and everything (studio， library， tools， etc) just works