redstone

local rsSignal = 0
while true do
   rsSignal = rs.getAnalogueInput("back")
   print("Redstone Strength:"..rsSignal)
   if rsSignal <= 7 then
      rs.setOutput ("left", true)
      print("Refueling")
        turtle.turnLeft()
        turtle.drop(1)
        turtle.turnRight()
   else
      rs.setOutput("left", false)
  end
     turtle.select(1)
   if turtle.getItemCount(1) < 1 then
     turtle.suckDown()
     print("Need Coal..")
  end
     print ("Waiting 10 sec..")
     sleep (10)
  end