Init commit with many years of arduino sketches and projects. I dont know if the esp8266 includes much, but there are also libraries. I hope they dont have crazy automatic versioning through the Arduino IDE.

Projects/ST_Two_Small_Clock/ST2_Sleep/ST2_Sleep.ino

@@ -0,0 +1,137 @@
+//*******************************************************************************************************************
+// 								                                 Enter Sleep Mode
+//*******************************************************************************************************************
+
+void GoToSleep()
+{
+      //  SLEEP_MODE_EXT_STANDBY
+
+   // PORTB = (PORTB & B10000000);                           // Clear ROWs and De-select Demux chip
+    UltraPowerDown(false);
+
+    attachInterrupt(0, MinuteUP, FALLING);
+    set_sleep_mode(SLEEP_MODE_PWR_DOWN);                                        //   was   (SLEEP_MODE_EXT_STANDBY);
+    cli();
+    //      if (some_condition)
+    //      {
+    sleep_enable();
+    //       sleep_bod_disable();
+    sei();
+    sleep_cpu();
+//    _NOP();
+//    _NOP();
+    sleep_disable();
+    //      }
+    sei();
+
+    detachInterrupt(0);
+    
+    UltraPowerDown(true);
+    
+    blinkFlag = false;                                                         // Incase sleep started during time set
+//    MODEOVERRIDEFLAG = false;
+    NextStateFlag = false;
+    
+    NextStateRequest = false;
+    NextSUBStateRequest = false;
+    
+    SetTimeFlag = false;
+//    SetDigit = 4;
+    
+    STATE = 0;
+    SUBSTATE = 0;
+    JustWokeUpFlag = true;
+    
+//    CheckAlarm();
+ //   if(ALARM1FLAG)
+//    {
+//      ALARM1FLAG = false;
+//      EnableAlarm1(false);
+//      STATE = 90;
+//    }
+    
+//    displayString("Wake");
+//    delay(1000);
+//    clearmatrix();
+    
+    SleepTimer = millis();
+  
+  
+}
+
+//*******************************************************************************************************************
+// 								                                MAX power Savings
+//*******************************************************************************************************************
+void UltraPowerDown(boolean onoff)
+{
+  if(onoff)                                                    // True = full power mode = ON
+  {
+//  pinMode(4, OUTPUT);                                      // DeMux A
+//  pinMode(5, OUTPUT);                                      // DeMux B
+//  pinMode(6, OUTPUT);                                      // DeMux C
+//  pinMode(7, OUTPUT);                                      // DeMux D  
+    
+   power_timer1_enable();                                       // Used for LED matrix refresh
+   power_timer0_enable();                                       // Seems required (for delay ?)
+   power_timer2_enable();                                       // Seems required for tone (crashes without)
+   
+   power_twi_enable();
+  }
+  else                                                        // False is LOW Power mode
+  {
+    // LED MATRIX
+    //
+    // Port C: C0 to C3 set to high. Columns 17 to 20 of LED matrix - Cathode connection
+    PORTC = (PORTC & B11110000) | B00001111;
+    
+    // Port B: Unselect the MUX chip
+    PORTB = (1<<PORTB7);
+    // Port B: Set all the ROWs to high: High on both cathode and annode = no current ?
+    PORTB = PORTB | B01111111;     // Could be PORTB =B11111111;
+    
+ // pinMode(4, INPUT);                                      // DeMux A // Set these to inputs to lower current on mux inputs
+ // pinMode(5, INPUT);                                      // DeMux B
+ // pinMode(6, INPUT);                                      // DeMux C
+//  pinMode(7, INPUT);                                      // DeMux D 
+
+    PORTD = (PORTD & B00001111) | B11110000 ;                     // SET all address pins
+    
+    
+    // Other Peripherals
+    //
+   power_timer1_disable();                                       // Used for LED matrix refresh
+   power_timer0_disable();                                       // Seems required (for delay ?)
+   power_timer2_disable();                                       // Seems required for tone (crashes without)
+   
+   power_twi_disable();
+   
+   PORTC = PORTC | 1 << PORTC4;                                  // Set SDA and SCL to high so they do not pull current from external pull-up
+   PORTC = PORTC | 1 << PORTC5; 
+ 
+  DDRC = DDRC | 1 << PORTC4;                                      // Make SDA and SCL inputs = lower current
+  DDRC = DDRC | 1 << PORTC5;                                      //
+  }
+  
+}
+
+//*******************************************************************************************************************
+// 								 WAKE-UP - Called by Interrupt 0 on Digital pin 2
+//*******************************************************************************************************************
+
+void MinuteUP()
+{
+  MINUP = true;
+}
+
+/*
+void MinuteDOWN()
+{
+
+}
+*/
+
+void ResetSleepCount()
+{
+      SleepTimer = millis();
+}     
+