startup.lua

-- Finds the first energy buffer (your AE2 acceptor) and a monitor,
-- then shows stored energy & approximate FE/t on the monitor.

local dev = peripheral.find("energy_storage")
assert(dev, "No energy_storage peripheral found (check wired modem ON & cabling)")

local mon = peripheral.find("monitor")
assert(mon, "No monitor found. Place one and connect (touching or via wired modem).")

-- make the monitor comfy to read
mon.setTextScale(1.5)           -- try 2.0 on very large monitors, 1.0 on small ones
mon.setBackgroundColor(colors.black)
mon.setTextColor(colors.white)

local function drawOn(termLike, lines)
  local old = term.redirect(termLike)
  term.clear(); term.setCursorPos(1,1)
  for i, line in ipairs(lines) do
    term.setCursorPos(1, i); term.clearLine(); term.write(line)
  end
  term.redirect(old)
end

local lastE = dev.getEnergy()
local lastT = os.clock()

while true do
  sleep(1.0)                                   -- sample every ~1s
  local nowE = dev.getEnergy()
  local cap  = dev.getEnergyCapacity()
  local nowT = os.clock()

  local dE = nowE - lastE
  local dt = math.max(nowT - lastT, 0.05)
  local fe_per_s = dE / dt
  local fe_per_t = fe_per_s / 20               -- 20 ticks per second

  local lines = {
    ("Power meter"):upper(),
    string.rep("-", 24),
    ("Stored: %d / %d FE"):format(nowE, cap),
    ("Flow: %.1f FE/t  (+gen / -use)"):format(fe_per_t),
    "",
    "Tip: enlarge monitor or tweak setTextScale."
  }

  -- draw to the monitor
  drawOn(mon, lines)
  -- (optional) also draw in the computer terminal:
  drawOn(term.current(), lines)

  lastE, lastT = nowE, nowT
end