add optional delay after PCD_Init as workaround

provided by DarkiStar #476

examples/DumpInfo/DumpInfo.ino

@@ -46,6 +46,7 @@ void setup() {
 	while (!Serial);		// Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
 	SPI.begin();			// Init SPI bus
 	mfrc522.PCD_Init();		// Init MFRC522
+	delay(4);				// Optional delay. Some board do need more time after init to be ready, see Readme
 	mfrc522.PCD_DumpVersionToSerial();	// Show details of PCD - MFRC522 Card Reader details
 	Serial.println(F("Scan PICC to see UID, SAK, type, and data blocks..."));
 }