cocoa

 function dig()
    if turtle.getItemCount(15) > 0 then
        turtle.select(1)
        turtle.placeUp()
        slot = 2
        for x=1, 15 do
            turtle.select(slot)
            turtle.dropUp()
            slot = slot + 1
        end
        turtle.select(1)
        turtle.digUp()
        turtle.select(2)
    end
    turtle.dig()
end

function place()
    for bean=2, 16 do
        if turtle.getItemCount(bean) > 0 then
            turtle.select(bean)
            turtle.place()
            return
        end
    end
end

 function row()
     for x=1, 8 do
        dig()
        place()
        if right == true then
            turtle.turnRight()
            turtle.forward()
            turtle.turnLeft()
        else
            turtle.turnLeft()
            turtle.forward()
            turtle.turnRight()
        end
    end
    dig()
    place()
end

function harvest()
    right = true
    row()
    turtle.up()
    right = false
    row()
    turtle.up()
    right = true
    row()
    turtle.up()
    right = false
    row()
    for x=1, 3 do
        turtle.down()
    end
end

while true do
    harvest()
    sleep(600)
end