startup.lua

print("Staring Wither Spawn Controller!")

function pulse( _nSide,  _nTime )
    print("Sending Redstone Pulse")
    redstone.setOutput( _nSide, true)
    sleep(_nTime)
    redstone.setOutput( _nSide, false)
end

while true do
    sleep(0.1)
    if redstone.getInput("top") == true then
        if redstone.getAnalogInput("right") == 0 then
           pulse("back", 1)
        else
           sleep(2)
        end
    end
end