fix #414; note need mbed example in arduino.md

RF24_config.h

@@ -123,7 +123,7 @@
  #endif // !defined(__arm__) && !defined (__ARDUINO_X86__)
 
  #ifndef _BV
- #define _BV(x) (1<<(x))
+  #define _BV(x) (1<<(x))
  #endif
  #endif // defined (ARDUINO) && !defined (__arm__) && !defined (__ARDUINO_X86__)
 
@@ -159,38 +159,41 @@
  #if !defined (ARDUINO) // This doesn't work on Arduino DUE
  typedef char const char;
 
+ #elif defined (ARDUINO_ARCH_SAMD)
+ #define printf Serial.printf
+
  #else // Fill in pgm_read_byte that is used, but missing from DUE
- #ifdef ARDUINO_ARCH_AVR
- #include <avr/pgmspace.h>
- #endif
- #ifndef pgm_read_byte
- #define pgm_read_byte(addr) (*(const unsigned char *)(addr))
- #endif
+  #if defined (ARDUINO_ARCH_AVR) || defined (ARDUINO_ARCH_SAMD)
+  #include <avr/pgmspace.h>
+  #endif
+  #ifndef pgm_read_byte
+  #define pgm_read_byte(addr) (*(const unsigned char *)(addr))
+  #endif
  #endif // !defined (ARDUINO)
 
  #ifndef prog_uint16_t
- typedef uint16_t prog_uint16_t;
+  typedef uint16_t prog_uint16_t;
  #endif
  #ifndef PSTR
- #define PSTR(x) (x)
+  #define PSTR(x) (x)
  #endif
  #ifndef printf_P
- #define printf_P printf
+  #define printf_P printf
  #endif
  #ifndef strlen_P
- #define strlen_P strlen
+  #define strlen_P strlen
  #endif
  #ifndef PROGMEM
- #define PROGMEM
+  #define PROGMEM
  #endif
  #ifndef pgm_read_word
- #define pgm_read_word(p) (*(p))
+  #define pgm_read_word(p) (*(p))
  #endif
  #if !defined pgm_read_ptr || defined ARDUINO_ARCH_MBED
- #define pgm_read_ptr(p) (*(p))
+  #define pgm_read_ptr(p) (*(p))
  #endif
  #ifndef PRIPSTR
- #define PRIPSTR "%s"
+  #define PRIPSTR "%s"
  #endif
 
  #endif // !defined (ARDUINO) || defined (ESP_PLATFORM) || defined (__arm__) || defined (__ARDUINO_X86__) && !defined (XMEGA)

docs/arduino.md

@@ -248,3 +248,6 @@ void setup() {
  // ... continue with program as normal (see library examples/ folder)
 }
 ```
+
+#### Other platforms that support multiple SPI bus objects
+- need example for [ArduinoCore-mbed SPI library](https://github.com/arduino/ArduinoCore-mbed/tree/master/libraries/SPI) (applies to Arduino Nano 33 BLE boards)