Fix compatible problem on nodeMCU (ESP8266)

add delay(0) to reset the soft wdt

Author: jimaobian

DFRobotDFPlayerMini.cpp

@@ -33,6 +33,7 @@ uint16_t DFRobotDFPlayerMini::calculateCheckSum(uint8_t *buffer){
 void DFRobotDFPlayerMini::sendStack(){
   if (_sending[Stack_ACK]) {
     while (_isSending) {
+      delay(0);
       available();
     }
   }
@@ -81,7 +82,9 @@ void DFRobotDFPlayerMini::disableACK(){
 
 bool DFRobotDFPlayerMini::waitAvailable(){
   _isSending = true;
-  while (!available());
+  while (!available()){
+    delay(0);
+  }
   return _handleType != TimeOut;
 }
 
@@ -195,6 +198,7 @@ bool DFRobotDFPlayerMini::validateStack(){
 
 bool DFRobotDFPlayerMini::available(){
   while (_serial->available()) {
+    delay(0);
     if (_receivedIndex == 0) {
       _received[Stack_Header] = _serial->read();
 #ifdef _DEBUG
@@ -394,7 +398,6 @@ int DFRobotDFPlayerMini::readVolume(){
 
 uint8_t DFRobotDFPlayerMini::readEQ(){
   sendStack(0x44);
-  while (!available());
   if (waitAvailable()) {
     return read();
   }

examples/GetStarted/getStarted.ino

@@ -1,11 +1,11 @@
 /***************************************************
 DFPlayer - A Mini MP3 Player For Arduino
- <https://www.dfrobot.com/index.php?route=product/product&product_id=1121>
+ <https://www.dfrobot.com/index.php?route=product/product&search=mp3&description=true&product_id=1121>
  
  ***************************************************
  This example shows the basic function of library for DFPlayer.
  
- Created 2016-12-07
+ Created 2014-8-28
  By [Angelo qiao]([email protected])
  
  GNU Lesser General Public License.
@@ -15,7 +15,7 @@ DFPlayer - A Mini MP3 Player For Arduino
 
 /***********Notice and Trouble shooting***************
  1.Connection and Diagram can be found here
- <https://www.dfrobot.com/wiki/index.php/DFPlayer_Mini_SKU:DFR0299#Connection_Diagram>
+ <>
  2.This code is tested on Arduino Uno, Leonardo, Mega boards.
  ****************************************************/
 
@@ -40,7 +40,9 @@ void setup()
     Serial.println(F("Unable to begin:"));
     Serial.println(F("1.Please recheck the connection!"));
     Serial.println(F("2.Please insert the SD card!"));
-    while(true);
+    while(true){
+      delay(0); // Code to compatible with ESP8266 watch dog.
+    }
   }
   Serial.println(F("DFPlayer Mini online."));