[LUA] ComputerCraft PIN Display

-- ComputerCraft PIN Display
-- Install: pastebin get ewAZEHGu /startup

local mon = peripheral.wrap("top")
local pass = "0000"

local passlen = string.len(pass)
local press = "";
tblpad = {};
for i=0,10 do
tblpad[i] = {}
    for x=0,10 do
        tblpad[i][x] = "x"
    end
end

tblpad[2][2] = "1"
tblpad[4][2] = "2"
tblpad[6][2] = "3"
tblpad[2][3] = "4"
tblpad[4][3] = "5"
tblpad[6][3] = "6"
tblpad[2][4] = "7"
tblpad[4][4] = "8"
tblpad[6][4] = "9"
tblpad[4][5] = "0"

function drawpad()
    if  term.isColor() then
        mon.setBackgroundColor(colors.green)
    end
    mon.setCursorPos(1,1)
    mon.write("x-----x")
    mon.setCursorPos(1,2)
    mon.write("|1 2 3|")
    mon.setCursorPos(1,3)
    mon.write("|4 5 6|")
    mon.setCursorPos(1,4)
    mon.write("|7 8 9|")
    mon.setCursorPos(1,5)
    mon.write("x--0--x")
end

function countdown(c)
    for i=1,c do
    if  term.isColor() then
        mon.setBackgroundColor(colors.green)
    end
        mon.setCursorPos(1,1)
        mon.write("       ")
        mon.setCursorPos(1,2)
        mon.write("       ")
        mon.setCursorPos(1,3)
        mon.write("  [".. c .."]  ")
        mon.setCursorPos(1,4)
        mon.write("       ")
        mon.setCursorPos(1,5)
        mon.write("       ")
        sleep(1)
        c = c-1
    end
end

function dots()
    if  term.isColor() then
        mon.setBackgroundColor(colors.red)
    end
    mon.setCursorPos(1,1)
    mon.write("       ")
    mon.setCursorPos(1,2)
    mon.write("       ")
    mon.setCursorPos(1,3)
    mon.write("  ...  ")
    mon.setCursorPos(1,4)
    mon.write("       ")
    mon.setCursorPos(1,5)
    mon.write("       ")
end


function opendoor()
dots()
redstone.setOutput("top", true)
redstone.setOutput("left", true)
redstone.setOutput("right", true)
redstone.setOutput("bottom", true)
redstone.setOutput("front", true)
redstone.setOutput("back", true)
countdown(5)
redstone.setOutput("top", false)
redstone.setOutput("left", false)
redstone.setOutput("right", false)
redstone.setOutput("bottom", false)
redstone.setOutput("front", false)
redstone.setOutput("back", false)
dots()
drawpad()
end

function wrongpass()
    if  term.isColor() then
        mon.setBackgroundColor(colors.red)
    end
    mon.setCursorPos(1,1)
    mon.write("       ")
    mon.setCursorPos(1,2)
    mon.write("INVALID")
    mon.setCursorPos(1,3)
    mon.write("PINCODE")
    mon.setCursorPos(1,4)
    mon.write("ENTERED")
    mon.setCursorPos(1,5)
    mon.write("       ")
    sleep(4)
    drawpad()
end
drawpad()

while true do
    event, side, xPos, yPos = os.pullEvent("monitor_touch")
    if tblpad[xPos][yPos] ~= "x" then
        mon.setCursorPos(xPos, yPos)
    if  term.isColor() then
        mon.setBackgroundColor(colors.gray)
    end
        mon.write(tblpad[xPos][yPos])
        sleep(0.2)
        mon.setCursorPos(xPos, yPos)
    if  term.isColor() then
        mon.setBackgroundColor(colors.gray)
    end     mon.write(tblpad[xPos][yPos])
        press = press .. tblpad[xPos][yPos]
        if string.len(press) == passlen and press == pass then
            press = ""
            opendoor()
        elseif string.len(press) == passlen and press ~= pass then
            press = ""
            wrongpass()
        end
    end
end