SLEEP_TIME = 60 -- max. 71 minutes (= 4294 sec)

pin=4
gpio.mode(pin, gpio.OUTPUT)

for i=1,3 do
    gpio.write(pin,1)
    tmr.delay(1000000)
    gpio.write(pin,0)
    tmr.delay(1000000)
end

node.dsleep(SLEEP_TIME * 1000000)