#include  <Ticker.h>
 
#define SlowPin 13 //D7 GPIO13
#define FastPin 12 //D6 GPIO15
#define SwitchTime 0.5

Ticker SwitchTicker;
//https://github.com/esp8266/Arduino/blob/master/libraries/Ticker/src/Ticker.h

enum SwitchState {isoff,isslow,ison};
SwitchState swst = isoff;
SwitchState gost = isoff;

void changeState()
{
  if (swst != gost)
  {
    if (gost == ison) digitalWrite(FastPin, LOW); 
    else              digitalWrite(FastPin, HIGH); 
    swst = gost;
  }
  else
  {
    digitalWrite(SlowPin, HIGH);
    SwitchTicker.detach();
  }
}

void initSlowSwitch() 
{
  digitalWrite(SlowPin, HIGH);
  pinMode(SlowPin, OUTPUT);
  digitalWrite(FastPin, HIGH);
  pinMode(FastPin, OUTPUT);
}


void SlowSwitch(bool switchON)
{
  if (switchON) gost = ison;
  else          gost = isoff;
  if(swst != gost)
  {
    swst = isslow; 
    digitalWrite(SlowPin, LOW); 
    SwitchTicker.attach(SwitchTime, changeState);
  }
}