door_lock.lua

function main()
    local monitor_pos = args[4]
    init(monitor_pos)
    while true do
        local pin = ""
        for i = 1, 4 do
            -- Get input from monitor.
            local input = get_input()

            if input ~= nil then
                monitor = peripheral.wrap(input[2])
                pin = pin .. input[1]
                redstone.setAnalogOutput(sound_pos, 15)
                sleep(0.1)
                redstone.setAnalogOutput(sound_pos, 0)
                sleep(0.1)
            end
        end
        -- Check if code is right.
        if pin == correct_pin then
            -- Send redstone signal for (seconds).
            monitor.setBackgroundColor(32)
            monitor.clear()
            redstone.setAnalogOutput(redstone_pos, 15)
            sleep(4)
            redstone.setAnalogOutput(redstone_pos, 0)
        else
            sleep(0.2)
            for i = 1, 2 do
                monitor.setBackgroundColor(16384)
                monitor.clear()
                redstone.setAnalogOutput(sound_pos, 15)
                sleep(0.1)
                redstone.setAnalogOutput(sound_pos, 0)
                sleep(0.1)
            end
        end
        monitor.setBackgroundColor(32768)
        monitor.clear()
    end
end

function get_input()
    monitor.setTextScale(1.5)
    monitor.clear()
    term.clear()
    monitor.setBackgroundColor(4096)
    monitor.setCursorPos(2,1)
    monitor.write("789")
    monitor.setCursorPos(2,2)
    monitor.write("456")
    monitor.setCursorPos(2,3)
    monitor.write("123")
    monitor.setBackgroundColor(32768)
    local event, side, x, y = os.pullEvent()
    if event == "monitor_touch" then
        if x == 2 and y == 1 then
            return { "7", side }
        elseif x == 3 and y == 1 then
            return { "8", side }
        elseif x == 4 and y == 1 then
            return { "9", side }
        elseif x == 2 and y == 2 then
            return { "4", side }
        elseif x == 3 and y == 2 then
            return { "5", side }
        elseif x == 4 and y == 2 then
            return { "6", side }
        elseif x == 2 and y == 3 then
            return { "1", side }
        elseif x == 3 and y == 3 then
            return { "2", side }
        elseif x == 4 and y == 3 then
            return { "3", side }
        end
    end
    return nil
end

function init(monitor_pos)
    monitor = peripheral.wrap(monitor_pos)
end


args = {...}
correct_pin = args[1]
redstone_pos = args[2]
sound_pos = args[3]
monitor = nil
coroutine.yield()

main()