Modem: add retry if begin fails

Author: pennam

libraries/WiFiS3/src/Modem.cpp

@@ -30,14 +30,17 @@ ModemClass::~ModemClass() {
 }
 
 /* -------------------------------------------------------------------------- */
-void ModemClass::begin(int badurate){
+void ModemClass::begin(int badurate, int retry){
 /* -------------------------------------------------------------------------- */
    if(_serial != nullptr && !beginned) {
       _serial->begin(badurate);
       string res = "";
       _serial->flush();
       modem.timeout(500);
-      beginned = modem.write(string(PROMPT(_SOFTRESETWIFI)),res, "%s" , CMD(_SOFTRESETWIFI));
+      while(!beginned && retry > 0) {
+         beginned = modem.write(string(PROMPT(_SOFTRESETWIFI)),res, "%s" , CMD(_SOFTRESETWIFI));
+         retry -= 1;
+      }
       modem.timeout(MODEM_TIMEOUT);
    }
 }

libraries/WiFiS3/src/Modem.h

@@ -22,7 +22,7 @@ class ModemClass {
   ModemClass(UART * _serial);
   ~ModemClass();
 
-  void begin(int badurate = 115200);
+  void begin(int badurate = 115200, int retry = 3);
   void end();
   bool write(const std::string &cmd, std::string &str, const char * fmt, ...);
   void write_nowait(const std::string &cmd, std::string &str, const char * fmt, ...);