Fixes to enable WiFiEsp on Arduino Due and other SAM32 chips.

[gzabusek]

Fixes issue #26

Problem is SAM32 libs already contain RingBuffer used for the UART. Renamed the class and removed vsnprintf_P usage as its only present on AVRs.

[gzabusek]

The next commit fixes #23 issue

[lenny1972]

Hi, I'd like to know if in file "src/utility/WifiEspRingBuffer.h" there is a typo or not.
Specifically when you suggest to add:
+#ifndef WifiEspWifiEspRingBuffer_h
+#define WifiEspWifiEspRingBuffer_h

Is it correct or it has to be:
+#ifndef WifiEspRingBuffer_h
+#define WifiEspRingBuffer_h
??
By the other hand I'm trying to modify the library to get working with my Arduino DUE but the current version of some of the library's files have been changed (comparing to the version of this example). Is it possible to update the changes to the current library version or attach the modified library on Github?
Thanks in advance

[srolf]

With the following changes (on top of release 2.2.1), I was able to get it working on a Due and M0 (no Pro) which where tested against NTP example on Leonardo, Due and M0:

\Arduino\libraries\WiFiEsp\

• rename all RingBuffer to WiFiEspRingBuffer

\Arduino\libraries\WiFiEsp\src\utility\RingBuffer.h

• rename RingBuffer.h to WiFiEspRingBuffer.h

\Arduino\libraries\WiFiEsp\src\utility\RingBuffer.cpp

• rename RingBuffer.cpp to WiFiEspRingBuffer.cpp

\Arduino\libraries\WiFiEsp\src\utility\EspDrv.cpp

• add below line 20
  #include <stdarg.h>
  #if defined(__SAMD21G18A__) || defined(__SAM3X8E__)
  #define vsnprintf_P vsnprintf
  #endif

\Arduino\libraries\WiFiEsp\src\utility\debug.h

• add below the line 31
  #if defined(__SAMD21G18A__)
  #define Serial SerialUSB
  #endif

[srolf]

With the changes above, also a M0 Pro by using the native port is working.

[srolf]

By changing
#if defined(__SAMD21G18A__) || defined(__SAM3X8E__)
to
#if defined(__SAMD21G18A__) || defined(__SAM3X8E__) || defined(__CPU_ARC__)
it compiles/runs also on an Arduino 101 (tested with a MQTT PubSub example).

[sserena]

Not working for me. I'm using a Due. Going off the WebClient-example, client.connect(server, 80) does establish a connection, but client.available() is never true, causing it to disconnect instantly. I found that espSerial->available() is always zero, but that's as far as I got.
This said, if I set #define _ESPLOGLEVEL_ 4 in debug.h, the content (asciilogo .txt in this particular case) is actually received and printed.

[EduardoMarquez]

I work for Feather M0

[ghost]

Fix above from srolf worked for me with an Arduino MKRFOX1200 and ESP8266 AT module.

Thanks for this.