while True:
    # seting time from NTP, ESP8266 RTC is not reliable
    if (ntp_time_counter >= NTP_TIME_COUNTER):
        try:
            settime()
            ntp_time_counter = 0
        except:
            print("ERROR setting time; settime() failed")

    # combined, ~1000ms sleep in next 5 lines
    led_on()                    # GPIO 2 LED
    utime.sleep_ms(250)         # sleep for 250 ms
    led_off()                   # GPIO 2 LED
    temperature = read_temp()   # sleep for 750 ms
    readings_json = create_json(temperature)

    if (one_minute_counter >= 60):
        one_minute_counter = 0
        try:
            response = urequests.request("POST", urlstring, json = readings_json)
        except:
            print("ERROR sending json; HTTP POST urequests.request")

    ntp_time_counter += 1
    one_minute_counter += 1