-- blink.lua
GPIO = 3

function wait(n)
  os.execute("sleep " .. tonumber(n))
end

function cmd(c)
  print(c)
  os.execute(c)
end

cmd("echo " .. GPIO .. " > /sys/class/gpio/export")
cmd("echo out > /sys/class/gpio/gpio" .. GPIO .. "/direction")
n = 0
while n < 2 do
   cmd("echo 1 > /sys/class/gpio/gpio" .. GPIO .. "/value")
   wait(1)
   cmd("echo 0 > /sys/class/gpio/gpio" .. GPIO .. "/value")
   wait(1)
   n = n + 1
end
cmd("echo ".. GPIO .." > /sys/class/gpio/unexport")