furnace-watchdog.lua

furnace-watchdog.lua

-- Configuration

SAMPLE_INTERVAL_SECONDS = 5
SAMPLE_TRIGGER_COUNT = 6

FURNACE_SIDE = "left"

-- Startup banner

term.setCursorPos(1, 1)
term.clear()
print("Watchdog: starting")
print(string.format("Watchdog: polling every %d seconds", SAMPLE_INTERVAL_SECONDS))
print(string.format("Watchdog: trigger at %d samples", SAMPLE_TRIGGER_COUNT))
print()

-- Program loop

furnaceEmptySamples = 0

while (true) do
  os.sleep(SAMPLE_INTERVAL_SECONDS)
  
  local furnaceEmpty = redstone.getAnalogInput(FURNACE_SIDE) == 0
    
  if (furnaceEmpty) then
    furnaceEmptySamples = furnaceEmptySamples + 1
  else
    -- The furnace has been refilled, reset the watchdog.
    furnaceEmptySamples = 0
  end
  
  if (furnaceEmptySamples > 0 and furnaceEmptySamples < SAMPLE_TRIGGER_COUNT) then
    print(string.format("Watchdog: furnace found empty %d times", furnaceEmptySamples))
  elseif (furnaceEmptySamples == SAMPLE_TRIGGER_COUNT) then
    print(string.format("Watchdog: furnace found empty %d times, alerting", SAMPLE_TRIGGER_COUNT))
  end
end