Button

rednet.open("top")
local transmit = peripheral.wrap("top")
local freq
local rowLength=4
local func

function useFreq(id,value)
    transmit.setFreq(id)
    transmit.set(value)
    sleep(.2)
end

function blink(freq)
    useFreq(freq,true)
    sleep(.2)
    useFreq(freq,false)
end

function housekeeping()
    term.clear()
    term.setCursorPos(1,1)
end

function waitMsg()
    id,msg,dist = rednet.receive()
    for f,g in string.gmatch(tostring(msg),"(%a+):(%d+)") do
        func = f
        freq = tonumber(g)
    end
end

function housekeeping(text)
    term.clear()
    term.setCursorPos(math.random(1,4),math.random(1,8))
    term.write(text)
end

function send(freq)
    useFreq(freq,true)
    rednet.send(7,freq)
end

function store(freq)
    useFreq(freq,false)
    path()
end

function isElevator()
    local elevator

    if freq>rowLength then
        elevator = true
    else
        elevator = false
    end

    local level = math.ceil(freq/rowLength)

    if level>2 then
        rednet.send(15,elevator)
    elseif level<3 then
        rednet.send(15,not elevator)
    end

    rednet.send(9,not elevator)

    return elevator
end

function path()
    blink(1101)
    isElevator()
end

print(math.random(1,50))
sleep(1)
housekeeping()

while true do
    waitMsg()
    if func=="send" then
        send(freq)
    elseif func=="store" then
        store(freq)
    elseif func=="new" then
        blink(1101)
    end
    housekeeping("Did '"..func.."' for "..freq)
end