autoFell

--program that has a turtle check for trees over an 8x8 square of saplings. It takes wood back to a dump chest when full and picks up fuel when needed. it needs saplings in slot 16 to replant and wood in 15 to compare. Fuel goes in slot 13.

--chops down a tree when the turtle is positioned 1 block above the ground to clear the saplings.
function chopTree()
    if turtle.detect() == true then
        local h = 0
        turtle.dig()
        turtle.forward()
        turtle.digDown()
        turtle.up()
        turtle.select(16)
        turtle.placeDown()
        while turtle.compare(15) == true do
            turtle.digUp()
            h = h + 1
        end
        while h > 0 do
            turtle.down()
        end
    end
end

function patrolLine()
    local i = 0
    while i < 9 do
        chopTree()
        turtle.forward()
        i = i + 1
    end
end

function patrolAll()
    local i = 0
    while i < 4 do
        patrolLine()
        turtle.turnRight()
        turtle.forward()
        turtle.turnRight()
        patrolLine()
        turtle.turnLeft()
        turtle.forward()
        turtle.turnLeft()
        i = i + 1
    end
    i = 0
    turtle.forward()
    turtle.turnRight()
    while i < 8 do
        turtle.forward()
        i = i + 1
    end
end

--dumps logs then refuels from a chest above it if needed
function dumpLogs()
    local i = 0
    while i <= 13 do
        turtle.select(i)
        turtle.drop()
        i = i + 1
    end
    turtle.up()
    if turtle.getFuelLevel() > 200 then
        turtle.select(13)
        turtle.suck(64)
        turtle.refuel()
    end
    turtle.down()
    turtle.turnRight()
end

function getFuel()
    turtle.select(13)
    turtle.refuel()
end

--main
getFuel()
while turtle.getFuelLevel() >=50 do
    patrolAll()
    dumpLogs()
end