Description:
1. extension of 14 digital IO ports (12 servo interface) and power;
2. six analog IO ports and power;
3. one digital external power port terminal;
4. Digital-port external power supply and an onboard power supply automatic switching;
5. one External power input terminal and an input pin;
6. RS485 interface;
7. reset button;
8. xbee/Bluetooh Bee Bluetooth wireless data transmission interface;
9. APC220/Bluetooh V3 Bluetooth wireless data transmission interface;
10. IIC/I2C/TWI interface;
11. 3.3V output port;
12. SD card module interface