Development board functions and resource description: 1. Onboard low frequency 32.768khz 8m high frequency oscillator. 2. Onboard 8 bright red water lights and equipped to enable jumpers. 3. 4-way independent quality key input can be achieved such as separate buttons or adjust the DS1302. 4. Onboard RS232 serial communication circuit you can communicate with the computer. 5. DS1302 real-time clock and leads to the clock backup battery interface. 6. VS1838 infrared receiver the remote control can be carried out experiments. 7. RS485 communication circuit effectively improve the communication distance and multi-machine data transfer. 8. Buzzer sound circuit do all kinds of sound experiments. 9. Onboard BSL downloads support USB direct download to MCU. 10. External power supply 5.5 x 2.1 USB pin can supply. 11. Providing 3.3v and 5v power output. 12. Using the standard 14-pin JTAG interface support for hardware simulation. 13. Minimum system board removable for easy replacement of the same type chip. 14. All-pin lead by a double row of needles marked clearly. 15. To support the expansion NRF905 wireless module. 16. To support the expansion NRF24L01/CC1100 modules. 17. Temperature sensor circuit simply insert the sensor to work. 18. 2-channel AD converter circuit can be realized analog to digital conversion experiments. 19. 1602 LCD support. 20. Supports 12864 image LCD. 21. Onboard resettable fuse improving experimental safety.