farm.lua

--- Setup
-- This program requires Tuttle: https://gist.github.com/znepb/72981ce3e7a2e1f4e3423ed0b2ca9510
-- The turtle's home should have a chest below (the output chest) and a chest above (the fuel chest).
-- As well as this, there should be NO OBSTACLES within the farm's area. They will be destroyed over time as the farm works.

--- Configuration Section
-- The block to search for and dig
local block = "minecraft:wheat"
-- The item to deposit into chests
local item = "minecraft:wheat"
-- The seed item. This can be commented out for melon & pumpkins.
local seed = "minecraft:wheat_seeds"
-- The age of the crop when it is ready to be harvested. This can be commented out for pumpkins.
local age = 7
-- The home position of the turtle
local hX, hY, hZ
-- How many items have to be in the inventory to go home.
-- If the amount of seeds is large than homeThreshold + 16, then the turtle will return home.
local homeThreshold = 48
-- When the amount of fuel in the turtle is less than this, it will return home and refuel.
local fuelThreshold = 2048

--[[
Copyright 2023 Marcus Wenzel
Permission is hereby granted, free of charge, to any person obtaining a copy of 
this software and associated documentation files (the "Software"), to deal in 
the Software without restriction, including without limitation the rights to 
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
of the Software, and to permit persons to whom the Software is furnished to 
do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all 
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
SOFTWARE.
]]

local tuttle = require("tuttle")

local items = tuttle.scan()

local function countItems(item)
  local count = 0
  for i = 1, 16 do
    if turtle.getItemDetail(i) and turtle.getItemDetail(i).name == item then
      count = count + turtle.getItemCount(i)
    end
  end
  return count
end

print("Starting up")

while true do
  local blocks = tuttle.scan()

  local x, y, z = gps.locate()
  for i, v in pairs(blocks) do
    if v.y == -1 and v.name == block then
      if age and v.state and v.state.age == age or age == nil then
        tuttle.goToCoordinates(x + v.x, y, z + v.z, true)
        turtle.select(3)
        local exists, data = turtle.inspectDown()
        if exists and data.name == block then
          tuttle.dig("down")
          if seed then
            tuttle.select(seed)
            turtle.placeDown()
          end
        end
      end
    end
  end

  if countItems(item) > homeThreshold or countItems(seed) > homeThreshold + 24 or turtle.getFuelLevel() < fuelThreshold then
    tuttle.goToCoordinates(hX + 1, hY, hZ)
    tuttle.goToCoordinates(hX, hY, hZ)
    while tuttle.select(item) do turtle.dropDown() end

    local needToDrop = countItems(seed) - homeThreshold
    local attempts = 0

    if needToDrop > 0 then
      print("Dropping seeds")
      repeat
        local _, i = tuttle.select(seed)
        if i then
          local count = turtle.getItemCount(i)
          local amount = math.min(count, needToDrop)
          turtle.dropDown(amount)
          needToDrop = needToDrop - amount
        else
          break
        end
        attempts = attempts + 1
      until needToDrop <= 0 or attempts >= 17
    end

    if turtle.getFuelLevel() < fuelThreshold then
      local slot = 0
      for i = 1, 16 do
        if turtle.getItemCount(i) == 0 then
          turtle.select(i)
          turtle.suckUp()
          turtle.refuel()
          print("Refueled!")
          break
        end
      end
    end
    turtle.back()
  end
  sleep(1)
end