Merge pull request #441 from adafruit/SPIM3-variant

add macro SPI_32MHZ_INTERFACE to variant to select SPI or SPI1 to use 32mhz SPIM3

Author: ladyada

libraries/SPI/SPI.cpp

@@ -254,13 +254,30 @@ void SPIClass::detachInterrupt() {
   // Should be disableInterrupt()
 }
 
-#if SPI_INTERFACES_COUNT > 0
+// default to 0
+#ifndef SPI_32MHZ_INTERFACE
+#define SPI_32MHZ_INTERFACE 0
+#endif
+
+#if SPI_32MHZ_INTERFACE == 0
+  #define _SPI_DEV    NRF_SPIM3 // 32 Mhz
+  #define _SPI1_DEV   NRF_SPIM2
+
+#elif SPI_32MHZ_INTERFACE == 1
+  #define _SPI_DEV    NRF_SPIM2
+  #define _SPI1_DEV   NRF_SPIM3 // 32 Mhz
+
+#else
+  #error "not supported yet"
+#endif
+
+#if SPI_INTERFACES_COUNT >= 1
 // use SPIM3 for highspeed 32Mhz
-SPIClass SPI(NRF_SPIM3,  PIN_SPI_MISO,  PIN_SPI_SCK,  PIN_SPI_MOSI);
+SPIClass SPI(_SPI_DEV,  PIN_SPI_MISO,  PIN_SPI_SCK,  PIN_SPI_MOSI);
 #endif
 
-#if SPI_INTERFACES_COUNT > 1
-SPIClass SPI1(NRF_SPIM2, PIN_SPI1_MISO, PIN_SPI1_SCK, PIN_SPI1_MOSI);
+#if SPI_INTERFACES_COUNT >= 2
+SPIClass SPI1(_SPI1_DEV, PIN_SPI1_MISO, PIN_SPI1_SCK, PIN_SPI1_MOSI);
 #endif
 
 #endif // NRF52840_XXAA

variants/clue_nrf52840/variant.h

@@ -93,6 +93,12 @@ static const uint8_t A7  = PIN_A7 ;
  */
 #define SPI_INTERFACES_COUNT 2
 
+// nRF52840 has only one SPIM3 runing at highspeed 32Mhz
+// This assign SPIM3 to either: SPI (0), SPI1 (1).
+// If not defined, default to 0 or SPI.
+#define SPI_32MHZ_INTERFACE  1
+
+// SPI
 #define PIN_SPI_MISO         (14)
 #define PIN_SPI_MOSI         (15)
 #define PIN_SPI_SCK          (13)
@@ -102,7 +108,7 @@ static const uint8_t MOSI = PIN_SPI_MOSI ;
 static const uint8_t MISO = PIN_SPI_MISO ;
 static const uint8_t SCK  = PIN_SPI_SCK ;
 
-
+// SPI1
 #define PIN_SPI1_MISO         (35)
 #define PIN_SPI1_MOSI         (30)
 #define PIN_SPI1_SCK          (29)