Trading indicators - bollinger bands & SuperTrend & Volume

 study(shorttitle="BB_Vol_ST", title="BB_Vol_ST", overlay=true)

Factor=input(3, minval=1,maxval = 100)

Pd=input(7, minval=1,maxval = 100)

Up=hl2-(Factor*atr(Pd))

Dn=hl2+(Factor*atr(Pd))

TrendUp=close[1]>TrendUp[1]? max(Up,TrendUp[1]) : Up

TrendDown=close[1]<TrendDown[1]? min(Dn,TrendDown[1]) : Dn

Trend = close > TrendDown[1] ? 1: close< TrendUp[1]? -1: nz(Trend[1],1)

Tsl = Trend==1? TrendUp: TrendDown

linecolor = Trend == 1 ? green : red

plot(Tsl, color = linecolor , style = line , linewidth = 2,title = "SuperTrend")

plotshape(cross(close,Tsl) and close>Tsl , "Up Arrow", shape.triangleup,location.belowbar,green,0,0)

plotshape(cross(Tsl,close) and close<Tsl , "Down Arrow", shape.triangledown , location.abovebar, red,0,0)

//plot(Trend==1 and Trend[1]==-1,color = linecolor, style = circles, linewidth = 3,title="Trend")

plotarrow(Trend == 1 and Trend[1] == -1 ? Trend : na, title="Up Entry Arrow", colorup=lime, maxheight=60, minheight=50, transp=0)

plotarrow(Trend == -1 and Trend[1] == 1 ? Trend : na, title="Down Entry Arrow", colordown=red, maxheight=60, minheight=50, transp=0)

length = input(20, minval=1)

src = input(close, title="Source")

mult = input(2.0, minval=0.001, maxval=50)

basis = sma(src, length)

dev = mult * stdev(src, length)

upper = basis + dev

lower = basis - dev

plot(basis, color=red)

p1 = plot(upper, color=blue)

p2 = plot(lower, color=blue)

fill(p1, p2)