功能完整的1602LCD时钟实验

//按K1按键进入设定状态

//按K2,依次进入闹钟功能是否启用，闹钟时,分秒,年,月,日及时间时,分,秒的设置,直到退出设置状态

//按K3,调整是否起用闹钟和调节闹钟时,分,秒,年,月,日,时间的时,分,秒的数字

//LCD第二排中间显示小喇叭，表示启用闹钟功能，无则禁止闹钟功能（可在调整状态进行设置）

//正常状态,LCD上排最前面显示自定义字符,LCD下排最前面闪动 RICHMCU

//设置状态,LCD上排最前面显示 P ,下排最前面在设置闹钟时间时显示 alarm: ,其它状态显示 time

//年代变化2000 2099,星期自动转换-Fully functional experiment 1602 LCD clock

//press K1 button to enter setting state

//by K2, which in turn into the alarm clock function is enabled, the alarm clock, minutes, year, month, day and time when points, second set, until the exit setting state

//in K3, adjust whether use and adjust the alarm clock, alarm clock, seconds, year, month, day, time, and the number of seconds

//LCD among the second row shows little horn, says enable alarm clock function, without which prohibit the alarm clock function, can be set in the state of adjustment)

//normal state, the front on the LCD display custom characters, discharge the front LCD flashing　RICHMCU

//set the state, the front on the LCD display　P , the front bottom when set the alarm clock time display　alarm: , other state display　time

/ change/s 2000-2099, the automatic conversion