// Simple KnightRider pattern to test 8 IO pins driven by the ESP-12 using Arduino IDE for ESP

// Wiring notes:
// CH_PD and RESET must be connected to 3V3.
// GPIO15 must be connected to GND.
// GPIO0 must be connected to GND prior to uploading sketch, but otherwise can be used freely

byte pattern[] = {4,5,0,2, 16,14,12,13, 12,14,16, 2,0,5};
int pinIndex = 13;

void setup() {
  byte pins[] = {4,5,0,2, 16,14,12,13};
  for (byte i=0; i<8; i++) {
    pinMode( pins[i], OUTPUT);

// the loop function runs over and over again forever
void loop() {
  digitalWrite( pattern[pinIndex--], HIGH); // Off
  if (pinIndex==-1) pinIndex=13;
  digitalWrite( pattern[pinIndex], LOW); // ON

To learn how to start writing Sketches for the ESP8266 using the Arduino IDE, see Arduino IDE for ESP Quickstart Guide