redstone.setOutput("right",true)
redstone.setOutput("back",false)
local close = false
while close == false do
    local event, param = os.pullEvent()
    if event == "redstone" then
        local param1 = redstone.getInput("bottom")
        if param1 == true then
            print("Train detected")
            redstone.setOutput("right",false)
            sleep(3)
            print("Letting train go")
            redstone.setOutput("back",true)
            sleep(0.01)
            redstone.setOutput("back",false)
            sleep(2)
            redstone.setOutput("right",true)
        end
    else
        if param == "q" then
            close = true
        end
    end
end
redstone.setOutput("back",true)