function leds_on()
    gpio.write(3,gpio.HIGH)
    gpio.write(4,gpio.HIGH)
end
gpio.mode(3,gpio.OUTPUT)
gpio.mode(4,gpio.OUTPUT)
gpio.write(3,gpio.LOW)
gpio.write(4,gpio.LOW)
tmr.alarm(0,5000,tmr.ALARM_SINGLE,leds_on)