How to use heiken ashi candles???

Heiken ashi is not a part of MT4. Normally heiken ashi candels are generated by an indicatot. There are two ways to handle these candles.

1. You calculate the values yourself

2. You use iCustom to get the values from an indicator.

The EA don't need heiken ashi candels on the chart.

Here jt27, tweak it to your heart's delight and turn it to an EA. Good Luck! ;-)

//+------------------------------------------------------------------+
//|                                                  Heiken Ashi.mq4 |
//|                   Copyright 2006-2014, MetaQuotes Software Corp. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright   "2006-2014, MetaQuotes Software Corp."
#property link        "https://www.mql5.com"
#property description "We recommend the following chart settings (press F8 or select menu 'Charts'->'Properties...'):"
#property description " - on 'Color' Tab select 'Black' for 'Line Graph'"
#property description " - on 'Common' Tab disable 'Chart on Foreground' checkbox and select 'Line Chart' radiobutton"
#property strict

#property indicator_chart_window
#property indicator_buffers 4
#property indicator_color1 Red
#property indicator_color2 White
#property indicator_color3 Red
#property indicator_color4 White
#property indicator_width1 1
#property indicator_width2 1
#property indicator_width3 3
#property indicator_width4 3

//---
input color ExtColor1 = Red;    // Shadow of bear candlestick
input color ExtColor2 = White;  // Shadow of bull candlestick
input color ExtColor3 = Red;    // Bear candlestick body
input color ExtColor4 = White;  // Bull candlestick body
//--- buffers
double ExtLowHighBuffer[];
double ExtHighLowBuffer[];
double ExtOpenBuffer[];
double ExtCloseBuffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//|------------------------------------------------------------------|
void OnInit(void)
  {
   IndicatorShortName("Heiken Ashi");
   IndicatorDigits(Digits);
//--- indicator lines
   SetIndexStyle(0,DRAW_HISTOGRAM,0,1,ExtColor1);
   SetIndexBuffer(0,ExtLowHighBuffer);
   SetIndexStyle(1,DRAW_HISTOGRAM,0,1,ExtColor2);
   SetIndexBuffer(1,ExtHighLowBuffer);
   SetIndexStyle(2,DRAW_HISTOGRAM,0,3,ExtColor3);
   SetIndexBuffer(2,ExtOpenBuffer);
   SetIndexStyle(3,DRAW_HISTOGRAM,0,3,ExtColor4);
   SetIndexBuffer(3,ExtCloseBuffer);
//---
   SetIndexLabel(0,"Low/High");
   SetIndexLabel(1,"High/Low");
   SetIndexLabel(2,"Open");
   SetIndexLabel(3,"Close");
   SetIndexDrawBegin(0,10);
   SetIndexDrawBegin(1,10);
   SetIndexDrawBegin(2,10);
   SetIndexDrawBegin(3,10);
//--- indicator buffers mapping
   SetIndexBuffer(0,ExtLowHighBuffer);
   SetIndexBuffer(1,ExtHighLowBuffer);
   SetIndexBuffer(2,ExtOpenBuffer);
   SetIndexBuffer(3,ExtCloseBuffer);
//--- initialization done
  }
//+------------------------------------------------------------------+
//| Heiken Ashi                                                      |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
   int    i,pos;
   double haOpen,haHigh,haLow,haClose;
//---
   if(rates_total<=10)
      return(0);
//--- counting from 0 to rates_total
   ArraySetAsSeries(ExtLowHighBuffer,false);
   ArraySetAsSeries(ExtHighLowBuffer,false);
   ArraySetAsSeries(ExtOpenBuffer,false);
   ArraySetAsSeries(ExtCloseBuffer,false);
   ArraySetAsSeries(open,false);
   ArraySetAsSeries(high,false);
   ArraySetAsSeries(low,false);
   ArraySetAsSeries(close,false);
//--- preliminary calculation
   if(prev_calculated>1)
      pos=prev_calculated-1;
   else
     {
      //--- set first candle
      if(open[0]<close[0])
        {
         ExtLowHighBuffer[0]=low[0];
         ExtHighLowBuffer[0]=high[0];
        }
      else
        {
         ExtLowHighBuffer[0]=high[0];
         ExtHighLowBuffer[0]=low[0];
        }
      ExtOpenBuffer[0]=open[0];
      ExtCloseBuffer[0]=close[0];
      //---
      pos=1;
     }
//--- main loop of calculations
   for(i=pos; i<rates_total; i++)
     {
      haOpen=(ExtOpenBuffer[i-1]+ExtCloseBuffer[i-1])/2;
      haClose=(open[i]+high[i]+low[i]+close[i])/4;
      haHigh=MathMax(high[i],MathMax(haOpen,haClose));
      haLow=MathMin(low[i],MathMin(haOpen,haClose));
      if(haOpen<haClose)
        {
         ExtLowHighBuffer[i]=haLow;
         ExtHighLowBuffer[i]=haHigh;
        }
      else
        {
         ExtLowHighBuffer[i]=haHigh;
         ExtHighLowBuffer[i]=haLow;
        }
      ExtOpenBuffer[i]=haOpen;
      ExtCloseBuffer[i]=haClose;
     }
//--- done
   return(rates_total);
  }
//+------------------------------------------------------------------+

Just get the value(s) of the indicator(s) into EA/indicator (using iCustom) and do what you want with it.

You should encapsulate your iCustom calls to make your code self-documenting.
          take candle color hekin ashi - MQL4 and MetaTrader 4 #8-9 or #1 2018.02.21