Add getDataRate, add DISABLED to data rate enum

RF24.cpp

@@ -911,16 +911,22 @@ rf24_datarate_e RF24::getDataRate( void )
 
 void RF24::setCRCLength(rf24_crclength_e length)
 {
-  uint8_t config = read_register(CONFIG) & ~_BV(CRCO) ;
+  uint8_t config = read_register(CONFIG) & ~( _BV(CRCO) | _BV(EN_CRC)) ;
 
-  // Always make sure CRC hardware validation is actually on
-  config |= _BV(EN_CRC) ;
-
-  // Now config 8 or 16 bit CRCs - only 16bit need be turned on
-  // 8b is the default.
-  if( length == RF24_CRC_16 )
+  switch (length)
   {
-    config |= _BV( CRCO ) ;
+    case RF24_CRC_DISABLED:
+      break;
+
+    case RF24_CRC_8:
+      config |= _BV(EN_CRC);
+      break;
+
+    case RF24_CRC_16:
+    default:
+      config |= _BV(EN_CRC);
+      config |= _BV( CRCO );
+      break;
   }
 
   write_register( CONFIG, config ) ;
@@ -928,6 +934,24 @@ void RF24::setCRCLength(rf24_crclength_e length)
 
 /****************************************************************************/
 
+rf24_crclength_e RF24::getCRCLength(void)
+{
+  rf24_crclength_e result = RF24_CRC_DISABLED;
+  uint8_t config = read_register(CONFIG) & ( _BV(CRCO) | _BV(EN_CRC)) ;
+
+  if ( config & _BV(EN_CRC ) )
+  {
+    if ( config & _BV(CRCO) )
+      result = RF24_CRC_16;
+    else
+      result = RF24_CRC_8;
+  }
+
+  return result;
+}
+
+/****************************************************************************/
+
 void RF24::disableCRC( void )
 {
   uint8_t disable = read_register(CONFIG) & ~_BV(EN_CRC) ;

RF24.h

@@ -14,7 +14,7 @@
 
 typedef enum { RF24_PA_MIN = 0,RF24_PA_LOW, RF24_PA_HIGH, RF24_PA_MAX, RF24_PA_ERROR } rf24_pa_dbm_e ;
 typedef enum { RF24_1MBPS = 0, RF24_2MBPS, RF24_250KBPS } rf24_datarate_e;
-typedef enum { RF24_CRC_8 = 0, RF24_CRC_16 } rf24_crclength_e;
+typedef enum { RF24_CRC_DISABLED = 0, RF24_CRC_8, RF24_CRC_16 } rf24_crclength_e;
 
 /**
  * Driver for nRF24L01(+) 2.4GHz Wireless Transceiver
@@ -481,6 +481,13 @@ public:
    */
   void setCRCLength(rf24_crclength_e length);
 
+  /**
+   * Get the CRC length
+   *
+   * @return RF24_DISABLED if disabled or RF24_CRC_8 for 8-bit or RF24_CRC_16 for 16-bit
+   */
+  rf24_crclength_e getCRCLength(void);
+
   /**
    * Disable CRC validation
    *