Add ESP.getChipId() function to get ESP32's ChipID. (espressif#322)

* Add ESP.getChipId() function to get ESP32's ChipID. * change getChipId() to getEfuseMac()

Author: wemos

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::getEfuseMac(void)
+{
+ uint64_t _chipmacid;
+ esp_efuse_read_mac((uint8_t*) (&_chipmacid));
+ return _chipmacid;
+}

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 getEfuseMac();
+
 };
 
 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.getEfuseMac();//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);
+
+}