redstone pulse clock using computercraft turtles

print("Ctrl + T to terminate the program")

print("Which side should the turtle pulse?")
print("Valid options: front, back, left, right, top, bottom")
local side = read()

-- Validate input
local validSides = {front=true, back=true, left=true, right=true, top=true, bottom=true}

if not validSides[side] then
    print("Invalid side! Defaulting to 'front'")
    side = "front"
end

print("Redstone pulsing started on " .. side .. " side...")

while true do
    redstone.setOutput(side, true)
    sleep(0.1)
    redstone.setOutput(side, false)
    sleep(0.5)
end