farmer.lua

local component = require("component")
local robot = require("robot")
local event = require("event")
local computer = require("computer")
local isRunning = true
local isHarvestRunning = false
local harvestTimer = nil

local waitTimeMinutes = 1
local minChargePercent = 98

function strafeRow()
  for i=0,6,1 do
    robot.use()
    robot.forward()
  end
end

function strafeField()
  strafeRow()
  robot.turnLeft()
  robot.forward()
  robot.turnLeft()
  strafeRow()
  robot.turnRight()
  robot.forward()
  robot.turnRight()
  strafeRow()
end

function harvestField()
  strafeField()
  robot.turnAround()
  strafeField()
end

function drainToChest()
  for i=1,robot.inventorySize(),1 do
    robot.select(i)
    if (robot.count() > 0) then
      robot.dropDown()
    end
  end
  robot.select(1)
end

function needsPower()
  return (computer.energy()/computer.maxEnergy()*100 < minChargePercent)
end

function BeginHarvest()
      if (isHarvestRunning) then
        return
      end

      isHarvestRunning = true
      print("Collecting crops")
      harvestField()
      robot.turnAround()
      print("Draining to chest")
      drainToChest()
      if (needsPower()) then
        print("Needs Charging")
        robot.turnLeft()
        robot.forward()
        repeat
          print("Charging...")
          os.sleep(1)
        until (computer.energy()/computer.maxEnergy()*100 >= 99)
        robot.turnAround()
        robot.forward()
        robot.turnLeft()
        print("Chargine finished")
      end
      isHarvestRunning = false
      print("Waiting " .. waitTimeMinutes .. " minutes")
      print("Press X to stop program")
end

--BeginHarvest()
function ListenTest()
  print("Starting Harvest")
  print("Waiting " .. waitTimeMinutes .. " minutes")
  print("Press X to stop program")
  harvestTimer = event.timer(waitTimeMinutes * 60, BeginHarvest, math.huge)

  while isRunning do
    local test, _, keyval = event.pull(math.huge, "key_up")
    if (test ~= nil and keyval == 120) then
      event.cancel(harvestTimer)
      isRunning = false
    end
  end
end

ListenTest()