Fix output function in printf().

Author: embedded-kiddie

Printf.cpp

@@ -15,14 +15,14 @@ int printf(const char* fmt, ...) {
 	va_end(arg_ptr);
 
 	// output to the serial console through the 'Serial'
-#if	1
+#if	defined(ARDUINO_UNOR4_MINIMA)
+
 	len = Serial.write((uint8_t*)buf, (size_t)len);
-#else
+
+#else // ARDUINO_UNOR4_WIFI
+
 	len = Serial.print(buf);
-#endif
 
-#if defined(ARDUINO_UNOWIFIR4) && 1
-	delay(2); // UNO R4 WiFi needs some delay to fix buffer overrun
 #endif
 
 	return len;

examples/printf/printf.ino

@@ -9,12 +9,21 @@ void setup() {
   Serial.begin(9600);
   while (!Serial);
 
+#ifdef  ARDUINO_UNOR4_WIFI
+  // UNO R4 WiFi needs to wait for a while to complete Serial initialization.
+  delay(1000); // It requires at least 600 ms.
+#endif
+
+  u_int32_t t = micros();
+
 #define EPSILON 0.00001
 
   for (float f = 0.0; f <= 1.0 + EPSILON; f += 0.01) {
     printf("f = %5.3f\n", f);
     printf("e = %5.3e\n", f);
   }
+
+  Serial.println(micros() - t);
 }
 
 void loop() {