This is a port of an indicator I wrote for MT4 several years ago. At the time it was the only thing available that could accurately plot support/resistance lines in an automated way. Now there are many that do similar things, but I still think this is one of the cleanest and most straightforward ones to use.
Parameters:
Signal Bars - Number of candles to look back for the high and low.
Peak Bar - Which of the candles must be the high or low to be used as the support or resistance level.
Notes:
Setting Peak Bar to 3 gives the most accurate results. Lower values will give false signals and higher values might be late in generating a useful signal.
Adjust your Signal Bars according to the timeframe you use. For example, 20 days worth of candles on 1-hour or higher charts will produce strong entry signals.