quit = false
master = nil

rednet.open("top")

rednet.broadcast("NeedMaster!")

probes = sensors.getProbes("back", "Sensor")
for i,v in ipairs(probes) do print(i,v) end

while not quit do
    event, p1, p2, p3 = os.pullEvent()
    if event == "rednet_message" then
        sender = p1
        message = p2
        distance = p3

        if message == "NeedSensors!" or message == "AmMaster" then
            master = sender
            if message == "NeedSensors!" then
                rednet.send(master, "AmSensor")
            end
        elseif message == "Scan" and sender == master then

        end
    end
end

rednet.close("top")