A special all-in-one breakout board with various functions:
buzzer switch
5V-3V Converter
IC 5V / 3V
IO level switch 4-way
RJ11 socket (for external module) P0 P1 P2 P8 P12 P13 P14 P15 P16 9
3-row pin IO pins
Slider
Microphone
4 full color LEDs 2
large colored buttons (KEYA, KEYB)
IIC
Ultrasonic socket Infrared receiving element
UART header