rewrite GetChipID.ino

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

@@ -1,17 +1,30 @@
-uint64_t chipid;  
+/* The true ESP32 chip ID is essentially its MAC address.
+This sketch provides an alternate chip ID that matches 
+the output of the ESP.getChipId() function on ESP8266 
+(i.e. a 32-bit integer matching the last 3 bytes of 
+the MAC address. This is less unique than the 
+MAC address chip ID, but is helpful when you need 
+an identifier that can be no more than a 32-bit integer 
+(like for switch...case).
+
+created 2020-06-07 by cweinhofer
+with help from Cicicok */
+
+uint32_t chipId = 0;
 
 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.
+	for(int i=0; i<17; i=i+8) {
+	  chipId |= ((ESP.getEfuseMac() >> (40 - i)) & 0xff) << i;
+	}
 
 	Serial.printf("ESP32 Chip model = %s Rev %d\n", ESP.getChipModel(), ESP.getChipRevision());
 	Serial.printf("This chip has %d cores\n", ESP.getChipCores());
-
+  Serial.print("Chip ID: "); Serial.println(chipId);
+
 	delay(3000);
 
 }