电路板中引脚的数量并未映射到ESP8266上的引脚数。因此，例如，电路板的引脚D1不映射到ESP8266的GPIO1（它实际上映射到GPIO5)

因此，正确的引脚映射如下[1] [2]（左侧为NodeMCU，右侧为ESP8266）：

D0 = GPIO16;
D1 = GPIO5;
D2 = GPIO4;
D3 = GPIO0;
D4 = GPIO2;
D5 = GPIO14;
D6 = GPIO12;
D7 = GPIO13;
D8 = GPIO15;
D9 = GPIO3;
D10 = GPIO1;
LED_BUILTIN = GPIO16（电路板LED的辅助常数，而不是电路板引脚）;

不过这些在官方库里已经定义好了。直接用就可的。

static const uint8_t SDA = PIN_WIRE_SDA;
static const uint8_t SCL = PIN_WIRE_SCL;

static const uint8_t LED_BUILTIN = 16;
static const uint8_t BUILTIN_LED = 16;
static const uint8_t D0   = 16;
static const uint8_t D1   = 5;
static const uint8_t D2   = 4;
static const uint8_t D3   = 0;
static const uint8_t D4   = 2;
static const uint8_t D5   = 14;
static const uint8_t D6   = 12;
static const uint8_t D7   = 13;
static const uint8_t D8   = 15;
static const uint8_t D9   = 3;
static const uint8_t D10  = 1;

示例代码：

因此，我们将使用定义的D0常数来控制LED，而无需担心映射到实际的ESP8266 GPIO引脚。

void setup() {
 
  pinMode(D0, OUTPUT); //Declare Pin mode
 
}
 
void loop() {
 
  digitalWrite(D0, HIGH);   //Turn the LED on
  delay(1000);              //Wait 1 second
  digitalWrite(D0, LOW);    //Turn the LED off
  delay(1000);              //Wait 1 second
 
}