wireless_redstone.lua

function P(name)
  return component.proxy(component.list(name)())
end

local redstone = P('redstone')
local modem = P('modem')
local sign = P('sign')

local PORT = 2001
local REDSTONE_SIDE = 2 -- sides.back

function sum(...)
  total = 0
  for i,v in ipairs({...}) do
    total = total + v
  end
  return total
end

function sum_string(my_string)
  return sum(string.byte(my_string, 1, -1))
end

function beep_string(my_string)
  tone = sum_string(my_string) % 1980
  tone = tone + 20
  computer.beep(tone)
end


modem.setWakeMessage('wake_wireless_redstone')
modem.open(PORT)

-- Startup "chime"
computer.beep(123)
computer.beep(234)
computer.beep(345)

while true do
  local event, _, _, port, distance, message = computer.pullSignal()
  if event == 'modem_message' then
    local label = sign.getValue()
    label = string.gsub(label,"\n","")

    if label == message then
      beep_string(message)
      redstone.setOutput(REDSTONE_SIDE, 15)
      computer.pullSignal(0.5)
      redstone.setOutput(REDSTONE_SIDE, 0)
    end
  end
end