Change BUILTIN_LED to GPIO5

boards.txt

@@ -181,7 +181,7 @@ nano32.menu.UploadSpeed.512000.upload.speed=512000
 
 ##############################################################
 
-lolin32.name=WEMOS LoLin32
+lolin32.name=WEMOS LOLIN32
 
 lolin32.upload.tool=esptool
 lolin32.upload.maximum_size=1044464
@@ -194,7 +194,7 @@ lolin32.serial.disableRTS=true
 lolin32.build.mcu=esp32
 lolin32.build.core=esp32
 lolin32.build.variant=lolin32
-lolin32.build.board=LoLin32
+lolin32.build.board=LOLIN32
 
 lolin32.build.f_cpu=240000000L
 lolin32.build.flash_mode=dio

cores/esp32/Esp.cpp

@@ -212,3 +212,11 @@ bool EspClass::flashRead(uint32_t offset, uint32_t *data, size_t size)
 {
     return spi_flash_read(offset, (uint32_t*) data, size) == ESP_OK;
 }
+
+
+uint64_t EspClass::getChipId(void)
+{
+    uint64_t _chipid;
+    esp_efuse_read_mac((uint8_t*) (&_chipid));
+    return _chipid;
+}

cores/esp32/Esp.h

@@ -76,6 +76,8 @@ class EspClass
     bool flashWrite(uint32_t offset, uint32_t *data, size_t size);
     bool flashRead(uint32_t offset, uint32_t *data, size_t size);
 
+    uint64_t getChipId();
+
 };
 
 extern EspClass ESP;

libraries/ESP32/examples/ChipID/GetChipID/GetChipID.ino

@@ -0,0 +1,14 @@
+uint64_t chipid;  
+
+void setup() {
+	Serial.begin(115200);
+}
+
+void loop() {
+	chipid=ESP.getChipId();//The chip ID is essentially its MAC address(length: 6 bytes).
+	Serial.printf("ESP32 Chip ID = %04X",(uint16_t)(chipid>>32));//print High 2 bytes
+	Serial.printf("%08X\n",(uint32_t)chipid);//print Low 4bytes.
+
+	delay(3000);
+
+}

variants/lolin32/pins_arduino.h

@@ -11,7 +11,7 @@
 #define digitalPinToInterrupt(p)    (((p)<40)?(p):-1)
 #define digitalPinHasPWM(p)         (p < 34)
 
-static const uint8_t LED_BUILTIN = 2;
+static const uint8_t LED_BUILTIN = 5;
 #define BUILTIN_LED  LED_BUILTIN // backward compatibility
 
 static const uint8_t KEY_BUILTIN = 0;