RPi - Example updates, minor bmc driver change

- Modified spi transfernb hopefully for the last time, re #9
- Updated RPi examples to minimize CPU usage
- Updated transfer example for Arduino and RPi to exit TX mode after 4ms
per manufacturer. Improves multicast streaming.
- Bit of a cleanup on RPi examples

RPi/RF24/bcm2835.c

@@ -621,28 +621,17 @@ void __bcm2835_spi_transfernb(char* tbuf, char* rbuf, uint32_t len, uint8_t dela
         {
            bcm2835_peri_write_nb(fifo, tbuf[TXCnt]);
            TXCnt++;
+		   
         }	
         //Rx fifo not empty, so get the next received bytes
-	while(! (bcm2835_peri_read(paddr) & BCM2835_SPI0_CS_RXD) ){}
-        while(((bcm2835_peri_read(paddr) & BCM2835_SPI0_CS_RXD))&&( RXCnt < len ))
-        {
-		   
+	while(! (bcm2835_peri_read(paddr) & BCM2835_SPI0_CS_DONE) ){}
+	if(TXCnt == len){ bcm2835_peri_set_bits(paddr, 0, BCM2835_SPI0_CS_TA); if(delay){ delayMicroseconds(20);}}	
+        while(((bcm2835_peri_read(paddr) & BCM2835_SPI0_CS_RXD))&&( RXCnt < len )){		   
            rbuf[RXCnt] = bcm2835_peri_read_nb(fifo);
            RXCnt++;	   
-	   
         }
-	if(delay){ delayMicroseconds(10); }
-
     }
-
-    // Wait for DONE to be set
-    while (!(bcm2835_peri_read_nb(paddr) & BCM2835_SPI0_CS_DONE)){
-		
-	}
-    
-    // Set TA = 0, and also set the barrier
-    bcm2835_peri_set_bits(paddr, 0, BCM2835_SPI0_CS_TA);
-    if(delay){ delayMicroseconds(20);}
+	delayMicroseconds(5);
 }
 
 

RPi/RF24/examples/gettingstarted.cpp

@@ -42,7 +42,6 @@ using namespace std;
 RF24 radio(RPI_V2_GPIO_P1_15, RPI_V2_GPIO_P1_24, BCM2835_SPI_SPEED_8MHZ);
 
 
-
 // Radio pipe addresses for the 2 nodes to communicate.
 const uint8_t pipes[][6] = {"1Node","2Node"};
 //const uint64_t pipes[2] = { 0xABCDABCD71LL, 0x544d52687CLL };
@@ -61,7 +60,6 @@ int main(int argc, char** argv){
 
   // optionally, increase the delay between retries & # of retries
   radio.setRetries(15,15);
-
   // Dump the configuration of the rf unit for debugging
   radio.printDetails();
 
@@ -121,8 +119,6 @@ int main(int argc, char** argv){
 			unsigned long started_waiting_at = millis();
 			bool timeout = false;
 			while ( ! radio.available() && ! timeout ) {
-					// by bcatalin » Thu Feb 14, 2013 11:26 am
-					//delay(5); //add a small delay to let radio.available to check payload
 				if (millis() - started_waiting_at > 200 )
 					timeout = true;
 			}
@@ -156,6 +152,7 @@ int main(int argc, char** argv){
 
 		if ( role == role_pong_back )
 		{
+			
 			// if there is data ready
 			//printf("Check available...\n");
 
@@ -170,7 +167,6 @@ int main(int argc, char** argv){
 
 				radio.stopListening();
 				
-				// Seem to need a  delay, or the RPi is too quick
 				radio.write( &got_time, sizeof(unsigned long) );
 
 				// Now, resume listening so we catch the next packets.
@@ -179,6 +175,8 @@ int main(int argc, char** argv){
 				// Spew it
 				printf("Got payload(%d) %lu...\n",sizeof(unsigned long), got_time);
 				
+				delay(925); //Delay after payload responded to, minimize RPi CPU time
+				
 			}
 		
 		}

RPi/RF24/examples/gettingstarted_call_response.cpp

@@ -28,12 +28,12 @@ using namespace std;
 // CE Pin, CSN Pin, SPI Speed
 
 // Setup for GPIO 22 CE and CE1 CSN with SPI Speed @ 1Mhz
-//RF24 radio(RPI_V2_GPIO_P1_22, RPI_V2_GPIO_P1_26, BCM2835_SPI_SPEED_1MHZ);
+//RF24 radio(RPI_V2_GPIO_P1_22, BCM2835_SPI_CS1, BCM2835_SPI_SPEED_1MHZ);
 
-// Setup for GPIO 22 CE and CE0 CSN with SPI Speed @ 4Mhz
+// Setup for GPIO 15 CE and CE0 CSN with SPI Speed @ 4Mhz
 //RF24 radio(RPI_V2_GPIO_P1_15, BCM2835_SPI_CS0, BCM2835_SPI_SPEED_4MHZ);
 
-// Setup for GPIO 22 CE and CE0 CSN with SPI Speed @ 8Mhz
+// Setup for GPIO 15 CE and CE0 CSN with SPI Speed @ 8Mhz
 RF24 radio(RPI_V2_GPIO_P1_15, RPI_V2_GPIO_P1_24, BCM2835_SPI_SPEED_8MHZ);
 
 
@@ -48,14 +48,12 @@ uint8_t counter = 1;                                                          //
 int main(int argc, char** argv){
 
 
-  printf("RF24/examples/gettingstarted_call_response\n");
-
+  printf("RPi/RF24/examples/gettingstarted_call_response\n");
   radio.begin();
   radio.setAutoAck(1);                    // Ensure autoACK is enabled
   radio.enableAckPayload();               // Allow optional ack payloads
   radio.setRetries(1,15);                 // Smallest time between retries, max no. of retries
   radio.setPayloadSize(1);                // Here we are sending 1-byte payloads to test the call-response speed
-  //radio.powerUp();
   radio.printDetails();                   // Dump the configuration of the rf unit for debugging
 
 
@@ -76,9 +74,8 @@ int main(int argc, char** argv){
 	}
   }
 /***********************************/
-  // This simple sketch opens two pipes for these two nodes to communicate
+  // This opens two pipes for these two nodes to communicate
   // back and forth.
-
     if ( role == role_ping_out )    {
       radio.openWritingPipe(addresses[0]);
       radio.openReadingPipe(1,addresses[1]);
@@ -123,15 +120,15 @@ while (1){
 
   if ( role == role_pong_back ) {
     uint8_t pipeNo, gotByte;           		        // Declare variables for the pipe and the byte received
-    while( radio.available(&pipeNo)){              // Read all available payloads
+    if( radio.available(&pipeNo)){               	// Read all available payloads      
 	  radio.flush_tx();							 	// Clear any unused ACK payloads	  				  
       radio.read( &gotByte, 1 );
 													// Since this is a call-response. Respond directly with an ack payload.
 													// Ack payloads are much more efficient than switching to transmit mode to respond to a call
 	  radio.writeAckPayload(pipeNo,&gotByte, 1 );   // This can be commented out to send empty payloads.	  
-      
       printf("Sent response %d \n\r", gotByte);
-      
+	  delay(900); //Delay after a response to minimize CPU usage on RPi
+				  //Expects a payload every second      
    }
  }
 

RPi/RF24/examples/transfer.cpp

@@ -56,7 +56,7 @@ int main(int argc, char** argv){
   radio.begin();                           // Setup and configure rf radio
   radio.setChannel(1);
   radio.setPALevel(RF24_PA_MAX);
-  radio.setDataRate(RF24_2MBPS);
+  radio.setDataRate(RF24_1MBPS);
   radio.setAutoAck(1);                     // Ensure autoACK is enabled
   radio.setRetries(2,15);                  // Optionally, increase the delay between retries & # of retries
   radio.setCRCLength(RF24_CRC_8);
@@ -102,6 +102,7 @@ int main(int argc, char** argv){
 
 		long int cycles = 10000; 					//Change this to a higher or lower number.
 		
+		// unsigned long pauseTime = millis();		//Uncomment if autoAck == 1 ( NOACK )
 		startTime = millis();
 	
 		for(int i=0; i<cycles; i++){        		//Loop through a number of cycles
@@ -109,6 +110,13 @@ int main(int argc, char** argv){
       			if(!radio.writeFast(&data,32)){     //Write to the FIFO buffers
         			counter++;                      //Keep count of failed payloads
       			}
+				
+				//This is only required when NO ACK ( enableAutoAck(0) ) payloads are used
+		/*		if(millis() - pauseTime > 3){       // Need to drop out of TX mode every 4ms if sending a steady stream of multicast data
+					pauseTime = millis();		    
+					radio.txStandBy();				// This gives the PLL time to sync back up	
+				}
+		*/
 		}
 		stopTime = millis();
 

examples/Transfer/Transfer.ino

@@ -13,16 +13,13 @@ TMRh20 2014
  */
 
 
-
 #include <SPI.h>
-#include "nRF24L01.h"
 #include "RF24.h"
 #include "printf.h"
 
 /*************  USER Configuration *****************************/
                                           // Hardware configuration
-RF24 radio(48,49);                        // Set up nRF24L01 radio on SPI bus plus pins 7 & 8
-boolean RADIO_NO = 0;  //SET THIS TO 0 or 1 for 1st or 2nd radio
+RF24 radio(7,8);                        // Set up nRF24L01 radio on SPI bus plus pins 7 & 8
 
 /***************************************************************/
 
@@ -46,7 +43,6 @@ void setup(void) {
   radio.setAutoAck(1);                     // Ensure autoACK is enabled
   radio.setRetries(2,15);                   // Optionally, increase the delay between retries & # of retries
   radio.setCRCLength(RF24_CRC_8); 
-  //radio.disableCRC();
   radio.openWritingPipe(pipes[0]);
   radio.openReadingPipe(1,pipes[1]);
   
@@ -77,12 +73,21 @@ void loop(void){
     unsigned long cycles = 10000; //Change this to a higher or lower number. 
     
     startTime = millis();
+    unsigned long pauseTime = millis();
             
     for(int i=0; i<cycles; i++){        //Loop through a number of cycles
       data[0] = i;                      //Change the first byte of the payload for identification
       if(!radio.writeFast(&data,32)){   //Write to the FIFO buffers        
         counter++;                      //Keep count of failed payloads
       }
+      
+      //This is only required when NO ACK ( enableAutoAck(0) ) payloads are used
+//      if(millis() - pauseTime > 3){
+//        pauseTime = millis();
+//        radio.txStandBy();          // Need to drop out of TX mode every 4ms if sending a steady stream of multicast data
+//        //delayMicroseconds(130);     // This gives the PLL time to sync back up   
+//      }
+      
     }
     
    stopTime = millis();   
@@ -93,8 +98,8 @@ void loop(void){
    float numBytes = cycles*32;
    float rate = numBytes / (stopTime - startTime);
     
-   printf("Transfer complete at "); Serial.print(rate); printf(" KB/s \n\r");
-   printf("%d of ",counter); Serial.print(cycles); printf(" Packets Failed to Send\n\r");
+   Serial.print("Transfer complete at "); Serial.print(rate); printf(" KB/s \n\r");
+   Serial.print(counter); Serial.print(" of "); Serial.print(cycles); printf(" Packets Failed to Send\n\r");
    counter = 0;   
     
    }
@@ -108,11 +113,10 @@ if(role == RX){
      }
    if(millis() - rxTimer > 1000){
      rxTimer = millis();     
-     printf("Rate: ");
-     float numBytes = counter*32;
-     Serial.print(numBytes/1000);
-     printf(" KB/s\n\r"); 
-     printf("Payload Count: %d \n\r", counter);
+     float numBytes = (counter*32)/1000.0;
+     Serial.print("Rate: ");
+     Serial.print(numBytes);
+     printf("KB/s \n Payload Count: %d \n\r", counter);
      counter = 0;
    }
   }
@@ -141,4 +145,3 @@ if(role == RX){
     }
   }
 }
-// vim:cin:ai:sts=2 sw=2 ft=cpp