Description Arduino compatible layout, based on atmega328p, aslo arduino programming compatible. Board choose arduino UNO. The key feature of this board is board Power VCC can be supplied by 5V or 3.3V, choose by switch. Output IO also same either 5V or 3.3V. Choose either voltage can program. Many devices use 3.3V as power supply, for example GPS, bluetooth, wifi esp8266, etc. Switch to use 3.3V can connect to 3.3V devices directly. On Board USB-TTL serial convert chip is CH340, when USB plugged on PC, the port can be found on IDE. On board LED indicator, power LED and pin D13 LED. All pins lead out again by side, and extra pins include: 2*4 VCC, GND pins VCC, GND, RX, TX, RST pins GND, VCC, SDA, SCL pins. R2 New Features: On board SD Card Slot, direct read and write, only on 3.3V select. On board XH2.0mm power jack, can attach rechargeable battery, supply to VCC to MCU directly. On board Infrared receiver on pin D2 and transmitter on pin D3, simple, common, mature and the cheapest wireless solutions.
