Turn off the second builtin Nodemcu 0.9 led
See this link which shows your second LED exactly (the image is for v1.0, I have v0.9 and the code below works just the same in this situation):

'Onboard LEDs? NodeMCU's got two!': 

https://lowvoltage.github.io/2017/07/09/Onboard-LEDs-NodeMCU-Got-Two

Quote:


  ESP-12 LED Blink:

 void setup() {
        pinMode(2, OUTPUT);     //Initialize GPIO2 pin as an output
 }

 void loop() {
   digitalWrite(2, LOW);   // Turn the LED on by making the voltage LOW   
   delay(1000);            // Wait for a second
   digitalWrite(2, HIGH);  // Turn the LED off by making the voltage HIGH 
   delay(2000);            // Wait for two seconds
 }



Or write it like this (ie. using 'D4' rather than '2'):


  ESP-12 LED Blink:

 void setup() {
        pinMode(**D4**, OUTPUT);     //Initialize GPIO2 pin as an output
 }

 void loop() {
   digitalWrite(**D4**, LOW);   // Turn the LED on by making the voltage LOW   
   delay(1000);            // Wait for a second
   digitalWrite(**D4**, HIGH);  // Turn the LED off by making the voltage HIGH 
   delay(2000);            // Wait for two seconds
 }



Regards, Geoff