Unify RF24 constructor API for all Linux platforms

- Define SPI config vars for non-Arduino systems:
RF24_BIT_ORDER, RF24_DATA_MODE, RF24_CLOCK_DIVIDER
- Allow use of standard RF24 constructor on RPi with default of 8Mhz SPI
clock speed
- Cleanup #ifdefs in RF24::csn();
- Fix compile on ATTiny

RF24.cpp

@@ -14,28 +14,8 @@
 
 void RF24::csn(bool mode)
 {
-	// Minimum ideal SPI bus speed is 2x data rate
-	// If we assume 2Mbs data rate and 16Mhz clock, a
-	// divider of 4 is the minimum we want.
-	// CLK:BUS 8Mhz:2Mhz, 16Mhz:4Mhz, or 20Mhz:5Mhz
-#if defined(ARDUINO)
-	#if  ( !defined(RF24_TINY) && !defined (__arm__)  && !defined (SOFTSPI)) || defined (CORE_TEENSY)
-		_SPI.setBitOrder(MSBFIRST);
-		_SPI.setDataMode(SPI_MODE0);
-		_SPI.setClockDivider(SPI_CLOCK_DIV2);
-	#endif
-#endif
-
-#if defined (RF24_RPi)
-	if(!mode){
 
-		_SPI.setBitOrder(BCM2835_SPI_BIT_ORDER_MSBFIRST);
-		_SPI.setDataMode(BCM2835_SPI_MODE0);
-		_SPI.setClockDivider(spi_speed);
-		_SPI.chipSelect(csn_pin);
-		delayMicroseconds(5);
-	}
-#elif defined (RF24_TINY)
+#if defined (RF24_TINY)
 	if (ce_pin != csn_pin) {
 		digitalWrite(csn_pin,mode);
 	} 
@@ -49,7 +29,30 @@ void RF24::csn(bool mode)
 			delayMicroseconds(11);  // allow csn to settle
 		}
 	}
-#elif !defined (ARDUINO_SAM_DUE) && !defined (RF24_LINUX)
+	// Return, CSN toggle complete
+	return;
+	
+#elif defined(ARDUINO)
+	// Minimum ideal SPI bus speed is 2x data rate
+	// If we assume 2Mbs data rate and 16Mhz clock, a
+	// divider of 4 is the minimum we want.
+	// CLK:BUS 8Mhz:2Mhz, 16Mhz:4Mhz, or 20Mhz:5Mhz
+	
+      #if !defined (SOFTSPI)	
+		_SPI.setBitOrder(MSBFIRST);
+		_SPI.setDataMode(SPI_MODE0);
+		_SPI.setClockDivider(SPI_CLOCK_DIV2);
+      #endif
+
+#elif defined (RF24_RPi)
+	  _SPI.setBitOrder(RF24_BIT_ORDER);
+	  _SPI.setDataMode(RF24_DATA_MODE);
+	  _SPI.setClockDivider(spi_speed ? spi_speed : RF24_CLOCK_DIVIDER);
+	  _SPI.chipSelect(csn_pin);
+	  delayMicroseconds(5);
+#endif
+
+#if !defined (RF24_LINUX)
 	digitalWrite(csn_pin,mode);
 	delayMicroseconds(5);
 #endif
@@ -71,7 +74,7 @@ uint8_t RF24::read_register(uint8_t reg, uint8_t* buf, uint8_t len)
   uint8_t status;
 
   #if defined (RF24_LINUX)
-  csn(LOW); //In this case, calling csn(LOW) configures the spi settings 
+  csn(LOW); //In this case, calling csn(LOW) configures the spi settings for RPi
   uint8_t * prx = spi_rxbuff;
   uint8_t * ptx = spi_txbuff;
   uint8_t size = len + 1; // Add register value to transmit buffer
@@ -86,7 +89,7 @@ uint8_t RF24::read_register(uint8_t reg, uint8_t* buf, uint8_t len)
 
   // decrement before to skip status byte
   while ( --size ){ *buf++ = *prx++; } 
-  csn(HIGH);
+
 #elif defined (RF24_DUE)
   status = _SPI.transfer(csn_pin, R_REGISTER | ( REGISTER_MASK & reg ), SPI_CONTINUE );
   while ( len-- > 1 ){
@@ -124,7 +127,7 @@ uint8_t RF24::read_register(uint8_t reg)
   
   _SPI.transfernb( (char *) spi_txbuff, (char *) spi_rxbuff, 2);
   result = *++prx;   // result is 2nd byte of receive buffer  
-  csn(HIGH);
+
   #elif defined (RF24_DUE)
   _SPI.transfer(csn_pin, R_REGISTER | ( REGISTER_MASK & reg ) , SPI_CONTINUE);
   result = _SPI.transfer(csn_pin,0xff);
@@ -158,7 +161,7 @@ uint8_t RF24::write_register(uint8_t reg, const uint8_t* buf, uint8_t len)
   
   _SPI.transfernb( (char *) spi_txbuff, (char *) spi_rxbuff, size);
   status = *prx; // status is 1st byte of receive buffer
-  csn(HIGH);
+
   #elif defined (RF24_DUE)
   	status = _SPI.transfer(csn_pin, W_REGISTER | ( REGISTER_MASK & reg ), SPI_CONTINUE );
     while ( --len){
@@ -196,7 +199,7 @@ uint8_t RF24::write_register(uint8_t reg, uint8_t value)
   	
 	_SPI.transfernb( (char *) spi_txbuff, (char *) spi_rxbuff, 2);
 	status = *prx++; // status is 1st byte of receive buffer
-	csn(HIGH);
+
   #elif defined (RF24_DUE)
   status = _SPI.transfer(csn_pin, W_REGISTER | ( REGISTER_MASK & reg ), SPI_CONTINUE);
   _SPI.transfer(csn_pin,value);
@@ -240,7 +243,7 @@ uint8_t RF24::write_payload(const void* buf, uint8_t data_len, const uint8_t wri
 	
 	_SPI.transfernb( (char *) spi_txbuff, (char *) spi_rxbuff, size);
 	status = *prx; // status is 1st byte of receive buffer
-	csn(HIGH);
+
  #elif defined (RF24_DUE)
 
   status = _SPI.transfer(csn_pin, writeType , SPI_CONTINUE);
@@ -312,7 +315,7 @@ uint8_t RF24::read_payload(void* buf, uint8_t data_len)
         *current++ = *prx++;
 		
 	*current = *prx;
-    csn(HIGH);
+
   #elif defined (RF24_DUE)
 
   status = _SPI.transfer(csn_pin, R_RX_PAYLOAD, SPI_CONTINUE );
@@ -372,7 +375,6 @@ uint8_t RF24::spiTrans(uint8_t cmd){
   #if defined (RF24_LINUX)
     csn(LOW);
     status = _SPI.transfer( cmd );
-	csn(HIGH);
   #elif defined (RF24_DUE)
 	status = _SPI.transfer(csn_pin, cmd );
   #else
@@ -578,7 +580,7 @@ void RF24::printDetails(void)
 		case BCM2835_SPI_SPEED_32KHZ : printf("32 KHz");	break ;
 		case BCM2835_SPI_SPEED_16KHZ : printf("16 KHz");	break ;
 		case BCM2835_SPI_SPEED_8KHZ  : printf("8 KHz");	break ;
-		default : printf("Probably Bad !!!");	break ;
+		default : printf("8 Mhz");	break ;
 	}
 	printf("\n================ NRF Configuration ================\n");
  
@@ -631,6 +633,7 @@ void RF24::begin(void)
 	switch(csn_pin){     //Ensure valid hardware CS pin
 	  case 0: break;
 	  case 1: break;
+	  // Allow BCM2835 enums for RPi
 	  case 8: csn_pin = 0; break;
 	  case 7: csn_pin = 1; break;
 	  default: csn_pin = 0; break;
@@ -657,7 +660,6 @@ void RF24::begin(void)
 	_SPI.setBitOrder(csn_pin,MSBFIRST);	// Set the bit order and mode specific to this device
   	_SPI.setDataMode(csn_pin,SPI_MODE0);
 	ce(LOW);
-  	//csn(HIGH);
   #else
     #if ! defined(LITTLEWIRE)
     if (ce_pin != csn_pin)

RF24.h

@@ -102,7 +102,7 @@ public:
   //#if defined (RF24_LINUX)
   
     /**
-  * Raspberry Pi Constructor
+  * Optional Raspberry Pi Constructor
   *
   * Creates a new instance of this driver.  Before using, you create an instance
   * and send in the unique pins that this chip is connected to.
@@ -115,7 +115,9 @@ public:
   RF24(uint8_t _cepin, uint8_t _cspin, uint32_t spispeed );
   //#endif
 
+  #if !defined (RF24_TINY)
   virtual ~RF24() {};
+  #endif
 
   /**
    * Begin operation of the chip
@@ -1307,8 +1309,10 @@ private:
  * @section News News
  *
  * **Feb 2015**<br>
- * - MRAA supported added ( Galileo, Edison, etc)
- * - BBB/Linux support via spidev & MRAA
+ * - <a href="MRAA.html">MRAA</a> support added ( Galileo, Edison, etc)
+ * - <a href="BBB.html">BBB/Linux </a> support via spidev & MRAA
+ * - Break out requirements for individual platforms to RF24/arch
+ * - Documentation cleanup & update
  *
  * <b>Dec 2014 </b><br>
  * - New: Intel Galileo now supported
@@ -1515,13 +1519,10 @@ private:
  *
  * @page BBB BeagleBone Black
  *
- * BeagleBone Black is supported via MRAA or SPIDEV, with MRAA being the preferred choice due to performance.
- *
- * @warning At the time of this writing MRAA support for BBB is not yet completed. RF24 support for MRAA via BBB is included
- * but is untested.
+ * BeagleBone Black is supported via MRAA or SPIDEV.
  *
- *  @note With SPIDEV, Users may need to edit the RF24/arch/BBB/spi.cpp file to configure the spi device. (Default:
- * "/dev/spidev1.0";; )
+ *  @note The SPIDEV option should to work with most Linux systems supporting SPIDEV. <br>
+ *  Users may need to edit the RF24/arch/BBB/spi.cpp file to configure the spi device. (Defaults: "/dev/spidev1.0";  or  "/dev/spidev1.1"; )
  *
  * <br>
  * @section AutoInstall Automated Install 
@@ -1556,8 +1557,8 @@ private:
  * 3. Change to the new RF24 directory
  *    @code cd RF24 @endcode
  * 4. Build the library, and run an example file: 
- *    @code sudo make install  OR  sudo make install RF24_MRAA=1 @endcode
  * **Note:** See the <a href="http://iotdk.intel.com/docs/master/mraa/index.html">MRAA </a> documentation for more info on installing MRAA
+ *    @code sudo make install  OR  sudo make install RF24_MRAA=1 @endcode
  * @code
  * cd examples_RPi  
  * @endcode
@@ -1571,10 +1572,12 @@ private:
  *   
  * @page MRAA MRAA
  *  
- * MRAA is a Low Level Skeleton Library for Communication on GNU/Linux platforms
- *
+ * MRAA is a Low Level Skeleton Library for Communication on GNU/Linux platforms <br>
  * See http://iotdk.intel.com/docs/master/mraa/index.html for more information
  *
+ * RF24 supports all MRAA supported platforms, but might not be tested on each individual platform due to the wide range of hardware support:<br>
+ * <a href="https://github.com/TMRh20/RF24/issues">Report an RF24 bug or issue </a>
+ *
  * @section Setup Setup
  * 1. Install the MRAA lib
  * 2. As per your device, SPI may need to be enabled
@@ -1618,8 +1621,8 @@ private:
  *
  * If SPI is not already enabled, load it on boot:
  * @code sudo raspi-config  @endcode
- * A. Update the tool via the menu as required
- * B. Select Advanced and enable the SPI kernel module
+ * A. Update the tool via the menu as required<br>
+ * B. Select **Advanced** and **enable the SPI kernel module** <br>
  * C. Update other software and libraries:
  * @code sudo apt-get update @endcode
  * @code sudo apt-get upgrade @endcode 
@@ -1709,6 +1712,12 @@ private:
  *  RF24 radio(RPI_BPLUS_GPIO_J8_15,RPI_BPLUS_GPIO_J8_24, BCM2835_SPI_SPEED_8MHZ);
  *  or
  *  RF24 radio(RPI_BPLUS_GPIO_J8_15,RPI_BPLUS_GPIO_J8_26, BCM2835_SPI_SPEED_8MHZ);
+ *
+ *  General:
+ *  RF24 radio(22,0);
+ *  or
+ *  RF24 radio(22,1);
+ *
  * @endcode
  * See the gettingstarted example for an example of pin configuration
  *
@@ -1716,13 +1725,13 @@ private:
  * <br><br>
  * **MRAA Constructor:**
  *
- * @code RF24 radio(15,24); @endcode
+ * @code RF24 radio(15,0); @endcode
  *
  * See http://iotdk.intel.com/docs/master/mraa/rasppi.html
  * <br><br>
  * **SPI_DEV Constructor**
  *
- * @code RF24 radio(22,8); @endcode
+ * @code RF24 radio(22,0); @endcode
  *
  * See http://pi.gadgetoid.com/pinout
  *

arch/RPi/RF24_arch_config.h

@@ -14,6 +14,9 @@
   #include "bcm2835.h"
   #include "spi.h"
   #define _SPI spi
+    #define RF24_BIT_ORDER BCM2835_SPI_BIT_ORDER_MSBFIRST
+	#define RF24_DATA_MODE BCM2835_SPI_MODE0
+	#define RF24_CLOCK_DIVIDER BCM2835_SPI_SPEED_8MHZ
 		
   // GCC a Arduino Missing
   #define _BV(x) (1<<(x))