51太阳能跟随系统，用户可选用 MCU 的外部中断连接 END_CALCU 引脚来检测 ASTRO 是否完成解算， 从而读取解算结果-51 solar energy to follow the system, the user can choose the MCU external interrupt to connect END_CALCU pin to detect the the ASTRO completion solver, which reads the solver resul