Simplified example to use less calls.

Defaults now to 32-byte payloads, but you can call in with any size under that.  Added example to docs.

.gitignore

@@ -1,2 +1,3 @@
+*.o
 .*.swp
 docs/

Doxyfile

@@ -631,7 +631,7 @@ EXCLUDE_SYMBOLS        =
 # directories that contain example code fragments that are included (see
 # the \include command).
 
-EXAMPLE_PATH           =
+EXAMPLE_PATH           = examples
 
 # If the value of the EXAMPLE_PATH tag contains directories, you can use the
 # EXAMPLE_PATTERNS tag to specify one or more wildcard pattern (like *.cpp
@@ -645,7 +645,7 @@ EXAMPLE_PATTERNS       =
 # commands irrespective of the value of the RECURSIVE tag.
 # Possible values are YES and NO. If left blank NO is used.
 
-EXAMPLE_RECURSIVE      = NO
+EXAMPLE_RECURSIVE      = YES
 
 # The IMAGE_PATH tag can be used to specify one or more files or
 # directories that contain image that are included in the documentation (see

RF24.cpp

@@ -80,7 +80,7 @@ uint8_t RF24::write_register(uint8_t reg, uint8_t value)
 
 /******************************************************************/
 
-uint8_t RF24::write_payload(const void* buf)
+uint8_t RF24::write_payload(const void* buf, uint8_t len)
 {
   uint8_t status;
 
@@ -88,9 +88,12 @@ uint8_t RF24::write_payload(const void* buf)
 
   csn(LOW);
   status = SPI.transfer( W_TX_PAYLOAD );
-  uint8_t len = payload_size;
+  uint8_t data_len = min(len,payload_size);
-  while ( len-- )
+  uint8_t blank_len = payload_size - data_len;
+  while ( data_len-- )
     SPI.transfer(*current++);
+  while ( blank_len-- )
+    SPI.transfer(0);
 
   csn(HIGH);
 
@@ -99,16 +102,19 @@ uint8_t RF24::write_payload(const void* buf)
 
 /******************************************************************/
 
-uint8_t RF24::read_payload(void* buf) 
+uint8_t RF24::read_payload(void* buf, uint8_t len) 
 {
   uint8_t status;
   uint8_t* current = (uint8_t*)buf;
 
   csn(LOW);
   status = SPI.transfer( R_RX_PAYLOAD );
-  uint8_t len = payload_size;
+  uint8_t data_len = min(len,payload_size);
-  while ( len-- )
+  uint8_t blank_len = payload_size - data_len;
+  while ( data_len-- )
     *current++ = SPI.transfer(0xff);
+  while ( blank_len-- )
+    SPI.transfer(0xff);
   csn(HIGH);
 
   return status;
@@ -181,7 +187,7 @@ void RF24::print_observe_tx(uint8_t value)
 /******************************************************************/
 
 RF24::RF24(int _cepin, int _cspin): 
-  ce_pin(_cepin), csn_pin(_cspin)
+  ce_pin(_cepin), csn_pin(_cspin), payload_size(32)
 {
 }
 
@@ -197,7 +203,6 @@ void RF24::setChannel(int channel)
 void RF24::setPayloadSize(uint8_t size)
 {
   payload_size = min(size,32);
-  write_register(RX_PW_P0,min(size,32));
 }
 
 /******************************************************************/
@@ -300,7 +305,7 @@ void RF24::stopListening(void)
 
 /******************************************************************/
 
-boolean RF24::write( const void* buf )
+boolean RF24::write( const void* buf, uint8_t len )
 {
   boolean result = false;
 
@@ -308,7 +313,7 @@ boolean RF24::write( const void* buf )
   write_register(CONFIG, _BV(EN_CRC) | _BV(PWR_UP));
 
   // Send the payload
-  write_payload( buf );
+  write_payload( buf, len );
 
   // Allons!
   ce(HIGH);
@@ -366,13 +371,13 @@ boolean RF24::available(void)
 
 /******************************************************************/
 
-boolean RF24::read( void* buf ) 
+boolean RF24::read( void* buf, uint8_t len ) 
 {
   // was this the last of the data available?
   boolean result = false;
 
   // Fetch the payload
-  read_payload( buf );
+  read_payload( buf, len );
 
   uint8_t fifo_status;
   read_register(FIFO_STATUS,&fifo_status,1);
@@ -391,6 +396,7 @@ void RF24::openWritingPipe(uint64_t value)
   
   write_register(RX_ADDR_P0, reinterpret_cast<uint8_t*>(&value), 5);
   write_register(TX_ADDR, reinterpret_cast<uint8_t*>(&value), 5);  
+  write_register(RX_PW_P0,min(payload_size,32));
 }
 
 /******************************************************************/

RF24.h

@@ -14,16 +14,20 @@
 /**
  * Driver for nRF24L01 2.4GHz Wireless Transceiver
  *
- * See <a href="http://www.nordicsemi.com/files/Product/data_sheet/nRF24L01_Product_Specification_v2_0.pdf">Datasheet</a>
+ * Please refer to:
+ *
+ * @li <a href="http://maniacbug.github.com/RF24/classRF24.html">Detailed Documentation</a>
+ * @li <a href="https://github.com/maniacbug/RF24/">Source Code</a>
+ * @li <a href="http://www.nordicsemi.com/files/Product/data_sheet/nRF24L01_Product_Specification_v2_0.pdf">Chip Datasheet</a>
  *
  * This chip uses the SPI bus, plus two chip control pins.  Remember that pin 10 must still remain an output, or
  * the SPI hardware will go into 'slave' mode.
  *
  * Design Goals: This library is designed to be...
- *   * Maximally compliant with the intended operation of the chip
+ * @li Maximally compliant with the intended operation of the chip
- *   * Easy for beginners to use
+ * @li Easy for beginners to use
- *   * Consumed with a public interface that's similiar to other Arduino standard libraries
+ * @li Consumed with a public interface that's similiar to other Arduino standard libraries
- *   * Built against the standard SPI library. 
+ * @li Built against the standard SPI library. 
  */
  
 class RF24
@@ -91,9 +95,10 @@ protected:
    * The size of data written is the fixed payload size, see getPayloadSize()
    * 
    * @param buf Where to get the data
+   * @param len Number of bytes to be sent
    * @return Current value of status register
    */
-  uint8_t write_payload(const void* buf);
+  uint8_t write_payload(const void* buf, uint8_t len);
 
   /**
    * Read the receive payload
@@ -101,9 +106,10 @@ protected:
    * The size of data read is the fixed payload size, see getPayloadSize()
    * 
    * @param buf Where to put the data
+   * @param len Maximum number of bytes to read
    * @return Current value of status register
    */
-  uint8_t read_payload(void* buf) ;
+  uint8_t read_payload(void* buf, uint8_t len) ;
 
   /**
    * Empty the receive buffer
@@ -222,12 +228,15 @@ public:
    * the receiver or the timeout/retransmit maxima are reached.  In
    * the current configuration, the max delay here is 60ms.
    *
-   * The size of data written is the fixed payload size, see getPayloadSize()
+   * The maximum size of data written is the fixed payload size, see 
+   * getPayloadSize().  However, you can write less, and the remainder
+   * will just be filled with zeroes.
    * 
    * @param buf Pointer to the data to be sent
+   * @param len Number of bytes to be sent
    * @return True if the payload was delivered successfully false if not
    */
-  boolean write( const void* buf );
+  boolean write( const void* buf, uint8_t len );
 
   /**
    * Test whether there are bytes available to be read
@@ -249,9 +258,10 @@ public:
    * for beginners to use.  No casting needed.
    *
    * @param buf Pointer to a buffer where the data should be written
+   * @param len Maximum number of bytes to read into the buffer
    * @return True if the payload was delivered successfully false if not
    */
-  boolean read( void* buf ) ;
+  boolean read( void* buf, uint8_t len ) ;
 
   /**
    * Open a pipe for writing
@@ -297,5 +307,20 @@ public:
   void openReadingPipe(uint8_t number, uint64_t address);
 
 };
+
+/**
+ * @example pingpair.pde
+ * 
+ * This is an example of how to use the RF24 class.  Write this sketch to two different nodes,
+ * connect the role_pin to ground on one.  The ping node sends the current time to the pong node,
+ * which responds by sending the value back.
+ */
+
+/**
+ * @mainpage Driver Library for nRF24L01
+ *
+ * See the RF24 class for details on how to drive this chip.
+ */
+
 #endif // __RF24_H__
 

examples/pingpair/.gitignore

@@ -0,0 +1 @@
+output/

examples/pingpair/makefile

@@ -0,0 +1,277 @@
+# Arduino Makefile
+# Arduino adaptation by mellis, eighthave, oli.keller
+# Modified by Kerry Wong to support NetBeans
+# Modified by Rob Gray (Graynomad) for use with Windows and no IDE
+#   This works in my environment and I use it to program two different 
+#   328-based boards and a Mega2560. It's not necessarily robust and 
+#   I may have broken something in the original file that I don't use.
+#
+# This makefile allows you to build sketches from the command line
+# without the Arduino environment.
+#
+# Instructions for using the makefile:
+#
+#  1. Copy this file into the folder with your sketch. The project code file
+#	  should have a .c extension however the file gets copied to a .cpp before
+#     compilation so you still write in C++.
+#
+#  2. Modify the lines between the double ### rows to set the paths 
+#     comm ports etc for your system. EG. c:/progra~1/arduino/arduino-00
+#     for the Arduino IDE, Note the use of short folder name, don't use
+#     "Program files" because spaces will break the build.
+#
+#     Set the line containing "MCU" to match your board's processor.
+#     Typically ATmega328 or ATmega2560.  If you're using a LilyPad Arduino,
+#     change F_CPU to 8000000.
+#
+#  3. At the command line, change to the directory containing your
+#     program's file and the makefile.
+#
+#  4. Type "make" and press enter to compile/verify your program.
+#     The default make target will also perform the uplode using avrdude.
+#
+#     The first time this is done all required libraries will be built
+#     and a core.a file will be created in the output folder.
+#
+#  NOTES:
+#     All output goes into a folder called "output" underneath the working folder.
+#     The default all: target creates symbol (.sym) and expanded assembly 
+#     (.lss) files and uploads the program.
+#
+#
+##########################################################
+##########################################################
+# Select processor here
+MCU 			= atmega328p
+#MCU 			= atmega2560
+
+ifeq ($(MCU),atmega2560)
+UPLOAD_RATE 	= 115200
+AVRDUDE_PROTOCOL = stk500v2
+COM 			= 39
+endif
+
+ifeq ($(MCU),atmega328p)
+UPLOAD_RATE 	= 57600
+AVRDUDE_PROTOCOL = stk500v1
+COM 			= 33
+endif
+
+ARDUINO_VERSION	= 22
+PROJECT_NAME 	= $(notdir $(PWD))
+PROJECT_DIR 	= . 
+ARDUINO_DIR 	= /opt/arduino-00$(ARDUINO_VERSION)
+ARDUINO_CORE 	= $(ARDUINO_DIR)/hardware/arduino/cores/arduino
+ARDUINO_AVR 	= $(ARDUINO_DIR)/hardware/tools/avr/avr/include/avr
+ARDUINO_LIB 	= $(ARDUINO_DIR)/libraries
+AVR_TOOLS_PATH 	= /usr/bin
+AVRDUDECONFIG_PATH = $(ARDUINO_DIR)/hardware/tools
+PORT 			= /dev/ttyUSB0
+PORT2 			= /dev/ttyUSB1
+F_CPU 			= 16000000
+
+##########################################################
+##########################################################
+
+# Note that if your program has dependencies other than those
+# already listed below, you will need to add them accordingly.
+C_MODULES =  \
+$(ARDUINO_CORE)/wiring_pulse.c \
+$(ARDUINO_CORE)/wiring_analog.c \
+$(ARDUINO_CORE)/pins_arduino.c \
+$(ARDUINO_CORE)/wiring.c \
+$(ARDUINO_CORE)/wiring_digital.c \
+$(ARDUINO_CORE)/WInterrupts.c \
+$(ARDUINO_CORE)/wiring_shift.c \
+
+CXX_MODULES = \
+$(ARDUINO_CORE)/Tone.cpp \
+$(ARDUINO_CORE)/main.cpp \
+$(ARDUINO_CORE)/WMath.cpp \
+$(ARDUINO_CORE)/Print.cpp \
+$(ARDUINO_CORE)/HardwareSerial.cpp \
+$(ARDUINO_LIB)/SPI/SPI.cpp \
+../../RF24.cpp
+
+CXX_APP 	= output/$(PROJECT_NAME).cpp
+MODULES 	= $(C_MODULES) $(CXX_MODULES)
+SRC 		= $(C_MODULES)
+CXXSRC 		= $(CXX_MODULES) $(CXX_APP)
+FORMAT 		= ihex
+
+# Name of this Makefile (used for "make depend").
+MAKEFILE = Makefile
+
+# Debugging format.
+# Native formats for AVR-GCC's -g are stabs [default], or dwarf-2.
+# AVR (extended) COFF requires stabs, plus an avr-objcopy run.
+#DEBUG = stabs
+DEBUG =
+
+OPT = s
+
+# Place -D or -U options here
+CDEFS = -DF_CPU=$(F_CPU)L -DARDUINO=$(ARDUINO_VERSION)
+CXXDEFS = -DF_CPU=$(F_CPU)L -DARDUINO=$(ARDUINO_VERSION)
+
+# Place -I options here
+CINCS = -I$(ARDUINO_CORE) -I$(ARDUINO_LIB) -I$(PROJECT_DIR) -I$(ARDUINO_AVR) -I$(ARDUINO_LIB)/SPI -I../..
+
+CXXINCS = -I$(ARDUINO_CORE) -I$(ARDUINO_LIB)
+
+# Compiler flag to set the C Standard level.
+# c89   - "ANSI" C
+# gnu89 - c89 plus GCC extensions
+# c99   - ISO C99 standard (not yet fully implemented)
+# gnu99 - c99 plus GCC extensions
+#CSTANDARD = -std=gnu99
+CDEBUG 		= -g$(DEBUG)
+#CWARN 		= -Wall -Wstrict-prototypes
+#CWARN 		= -Wall   # show all warnings
+CWARN 		= -w      # suppress all warnings
+CMAP		= -Wl,-Map,output.map 
+####CTUNING = -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
+CTUNING = -ffunction-sections -fdata-sections
+CXXTUNING = -fno-exceptions -ffunction-sections -fdata-sections
+#CEXTRA = -Wa,-adhlns=$(<:.c=.lst)
+MMCU 		= -mmcu=$(MCU)
+
+CFLAGS = $(CDEBUG) -O$(OPT) $(CMAP) $(CWARN) $(CTUNING) $(MMCU) $(CDEFS) $(CINCS) $(CSTANDARD) $(CEXTRA)
+CXXFLAGS = $(CDEBUG) -O$(OPT) $(CWARN) $(CXXTUNING) $(CDEFS) $(CINCS)
+#ASFLAGS = -Wa,-adhlns=$(<:.S=.lst),-gstabs
+LDFLAGS = -O$(OPT) -lm -Wl,--gc-sections
+#LDFLAGS = -O$(OPT) -lm -Wl,-Map,output/$(PROJECT_NAME).map 
+
+# Programming support using avrdude. Settings and variables.
+AVRDUDE_PORT = $(PORT)
+AVRDUDE_WRITE_FLASH = -U flash:w:output/$(PROJECT_NAME).hex:i
+
+AVRDUDE_FLAGS = -V -F -D -C $(AVRDUDECONFIG_PATH)/avrdude.conf \
+-p $(MCU) -c $(AVRDUDE_PROTOCOL) -b $(UPLOAD_RATE)
+
+# Program settings
+CC 			= $(AVR_TOOLS_PATH)/avr-gcc
+CXX 		= $(AVR_TOOLS_PATH)/avr-g++
+LD 			= $(AVR_TOOLS_PATH)/avr-gcc
+OBJCOPY 	= $(AVR_TOOLS_PATH)/avr-objcopy
+OBJDUMP 	= $(AVR_TOOLS_PATH)/avr-objdump
+AR 			= $(AVR_TOOLS_PATH)/avr-ar
+SIZE 		= $(AVR_TOOLS_PATH)/avr-size
+NM 			= $(AVR_TOOLS_PATH)/avr-nm
+AVRDUDE 	= $(AVR_TOOLS_PATH)/avrdude
+REMOVE 		= rm -f
+MV 			= mv -f
+
+# Define all object files.
+OBJ = $(SRC:.c=.o) $(CXXSRC:.cpp=.o) $(ASRC:.S=.o)
+OBJ_MODULES = $(C_MODULES:.c=.o) $(CXX_MODULES:.cpp=.o)
+
+# Define all listing files.
+LST = $(ASRC:.S=.lst) $(CXXSRC:.cpp=.lst) $(SRC:.c=.lst)
+
+# Combine all necessary flags and optional flags.
+# Add target processor to flags.
+ALL_CFLAGS 	= $(CFLAGS) -mmcu=$(MCU)
+ALL_CXXFLAGS = $(CXXFLAGS) -mmcu=$(MCU)
+ALL_ASFLAGS = -x assembler-with-cpp $(ASFLAGS) -mmcu=$(MCU)
+ALL_LDFLAGS = $(LDFLAGS) -mmcu=$(MCU)
+
+# Default target.
+# This is th etarget that gets executed with a make command
+# that has no parameters, ie "make".
+all: applet_files build sym lss size upload
+
+build: elf hex
+
+output/$(PROJECT_NAME).cpp: $(PROJECT_NAME).pde
+	test -d output || mkdir output
+	echo "#include <WProgram.h>" > $@ 
+	cat $< >> $@ 
+
+elf: output/$(PROJECT_NAME).elf
+hex: output/$(PROJECT_NAME).hex
+eep: output/$(PROJECT_NAME).eep
+lss: output/$(PROJECT_NAME).lss
+#sym: output/$(PROJECT_NAME).sym
+
+# Upload HEX file to Arduino
+upload: output/$(PROJECT_NAME).hex
+	$(AVRDUDE) $(AVRDUDE_FLAGS) -P $(PORT) $(AVRDUDE_WRITE_FLASH)
+	$(AVRDUDE) $(AVRDUDE_FLAGS) -P $(PORT2) $(AVRDUDE_WRITE_FLASH)
+
+sym:
+	$(NM) -n -C --format=posix output/$(PROJECT_NAME).elf > output/$(PROJECT_NAME).sym
+	
+# Display size of file.
+size:
+	$(SIZE) output/$(PROJECT_NAME).elf
+	
+# Convert ELF to COFF for use in debugging / simulating in AVR Studio or VMLAB.
+COFFCONVERT=$(OBJCOPY) --debugging \
+--change-section-address .data-0x800000 \
+--change-section-address .bss-0x800000 \
+--change-section-address .noinit-0x800000 \
+--change-section-address .eeprom-0x810000
+
+coff: output/$(PROJECT_NAME).elf
+	$(COFFCONVERT) -O coff-avr output/$(PROJECT_NAME).elf $(PROJECT_NAME).cof
+
+	extcoff: $(PROJECT_NAME).elf
+	$(COFFCONVERT) -O coff-ext-avr output/$(PROJECT_NAME).elf $(PROJECT_NAME).cof
+
+.SUFFIXES: .elf .hex .eep .lss .sym
+
+.elf.hex:
+	$(OBJCOPY) -O $(FORMAT) -R .eeprom $< $@
+
+.elf.eep:
+	$(OBJCOPY) -O $(FORMAT) -j .eeprom --set-section-flags=.eeprom="alloc,load" \
+	--no-change-warnings \
+	--change-section-lma .eeprom=0 $< $@
+
+# Create extended listing file from ELF output file.
+.elf.lss:
+	$(OBJDUMP) -h -S $< > $@
+
+# Link: create ELF output file from library.
+#output/$(PROJECT_NAME).elf: $(PROJECT_NAME).c output/core.a
+output/$(PROJECT_NAME).elf: output/$(PROJECT_NAME).o output/core.a
+	$(LD) $(ALL_LDFLAGS) -o $@ output/$(PROJECT_NAME).o output/core.a
+
+output/core.a: $(OBJ_MODULES)
+	@for i in $(OBJ_MODULES); do echo $(AR) rcs output/core.a $$i; $(AR) rcs output/core.a $$i; done
+
+# Compile: create object files from C++ source files.
+.cpp.o:
+	$(CXX) -c $(ALL_CXXFLAGS) $< -o $@
+
+# Compile: create object files from C source files.
+.c.o:
+	$(CC) -c $(ALL_CFLAGS) $< -o $@
+
+# Compile: create assembler files from C source files.
+.c.s:
+	$(CC) -S $(ALL_CFLAGS) $< -o $@
+
+# Assemble: create object files from assembler source files.
+.S.o:
+	$(CC) -c $(ALL_ASFLAGS) $< -o $@
+
+# Automatic dependencies
+%.d: %.c
+	$(CC) -M $(ALL_CFLAGS) $< | sed "s;$(notdir $*).o:;$*.o $*.d:;" > $@
+
+%.d: %.cpp
+	$(CXX) -M $(ALL_CXXFLAGS) $< | sed "s;$(notdir $*).o:;$*.o $*.d:;" > $@
+
+# Target: clean project.
+clean:
+	$(REMOVE) output/$(PROJECT_NAME).hex output/$(PROJECT_NAME).eep output/$(PROJECT_NAME).cof output/$(PROJECT_NAME).elf \
+	output/$(PROJECT_NAME).map output/$(PROJECT_NAME).sym output/$(PROJECT_NAME).lss output/core.a \
+	$(OBJ) $(LST) $(SRC:.c=.s) $(SRC:.c=.d) $(CXXSRC:.cpp=.s) $(CXXSRC:.cpp=.d)
+
+#.PHONY:	all build elf hex eep lss sym program coff extcoff clean applet_files sizebefore sizeafter
+.PHONY:		all build elf hex eep lss sym program coff extcoff applet_files sizebefore sizeafter
+
+#include $(SRC:.c=.d)
+#include $(CXXSRC:.cpp=.d)

examples/pingpair/pingpair.pde

@@ -29,13 +29,9 @@
 
 RF24 radio(8,9);
 
-// sets the address (and therefore the role of operation) of this unit.
+// sets the role of this unit in hardware.  Connect to GND to be the 'ping' sender.
-// lo = node0, hi = node1
+// Connect to +5V to be the 'pong' receiver.
-const int addr_pin = 7;
+const int role_pin = 7;
-
-// The actual value of the node's address will be filled in by the sketch
-// when it reads the addr_pin
-int node_address;
 
 //
 // Topology
@@ -47,21 +43,18 @@ const uint64_t pipes[2] = { 0xF0F0F0F0E1LL, 0xF0F0F0F0D2LL };
 //
 // Role management
 //
-// Set up address & role.  This sketch uses the same software for all the nodes
+// Set up role.  This sketch uses the same software for all the nodes
 // in this system.  Doing so greatly simplifies testing.  The hardware itself specifies
 // which node it is.
 //
-// This is done through the addr_pin.  Set it low for address #0, high for #1.
+// This is done through the role_pin
 //
 
 // The various roles supported by this sketch
-typedef enum { role_rx = 1, role_tx1, role_end } role_e;
+typedef enum { role_ping_out = 1, role_pong_back } role_e;
 
 // The debug-friendly names of those roles
-const char* role_friendly_name[] = { "invalid", "Receive", "Transmit"};
+const char* role_friendly_name[] = { "invalid", "Ping out", "Pong back"};
-
-// Which role is assumed by each of the possible hardware addresses
-const role_e role_map[2] = { role_rx, role_tx1 };
 
 // The role of the current running sketch
 role_e role;
@@ -69,17 +62,19 @@ role_e role;
 void setup(void)
 {
   //
-  // Address & Role
+  // Role
   //
   
-  // set up the address pin
+  // set up the role pin
-  pinMode(addr_pin, INPUT);
+  pinMode(role_pin, INPUT);
-  digitalWrite(addr_pin,HIGH);
+  digitalWrite(role_pin,HIGH);
-  delay(20); // Just to get a solid reading on the addr pin
+  delay(20); // Just to get a solid reading on the role pin
   
-  // read the address pin, establish our address and role
+  // read the address pin, establish our role
-  node_address = digitalRead(addr_pin) ? 0 : 1;
+  if ( digitalRead(role_pin) )
-  role = role_map[node_address];
+    role = role_pong_back;
+  else
+    role = role_ping_out;
 
   //
   // Print preamble
@@ -87,8 +82,7 @@ void setup(void)
   
   Serial.begin(9600);
   printf_begin();
-  printf("\n\rRF24 pingpair example\n\r");
+  printf("\n\rRF24/examples/pingpair/\n\r");
-  printf("ADDRESS: %x\n\r",node_address);
   printf("ROLE: %s\n\r",role_friendly_name[role]);
 
   //
@@ -97,31 +91,25 @@ void setup(void)
   
   radio.begin();
 
-  // Set channel (optional)
-  radio.setChannel(1);
-  
-  // Set size of payload (optional, but recommended)
-  // The library uses a fixed-size payload, so if you don't set one, it will pick
-  // one for you!
-  radio.setPayloadSize(sizeof(unsigned long));
-    
   //
-  // Open pipes to other nodes for communication (required)
+  // Open pipes to other nodes for communication
   //
   
   // This simple sketch opens two pipes for these two nodes to communicate
   // back and forth.
+  // Open 'our' pipe for writing
+  // Open the 'other' pipe for reading, in position #1 (we can have up to 5 pipes open for reading)
   
-  // We will open 'our' pipe for writing
+  if ( role == role_ping_out )
-  radio.openWritingPipe(pipes[node_address]);
+  {
-  
+    radio.openWritingPipe(pipes[0]);
-  // We open the 'other' pipe for reading, in position #1 (we can have up to 5 pipes open for reading)
+    radio.openReadingPipe(1,pipes[1]);
-  int other_node_address;
+  }
-  if (node_address == 0)
-    other_node_address = 1;
   else
-    other_node_address = 0;
+  {
-  radio.openReadingPipe(1,pipes[other_node_address]);
+    radio.openWritingPipe(pipes[1]);
+    radio.openReadingPipe(1,pipes[0]);
+  }
 
   //
   // Start listening
@@ -139,10 +127,10 @@ void setup(void)
 void loop(void)
 {
   //
-  // Transmitter role.  Repeatedly send the current time
+  // Ping out role.  Repeatedly send the current time
   //
   
-  if (role == role_tx1)
+  if (role == role_ping_out)
   {
     // First, stop listening so we can talk.
     radio.stopListening();
@@ -150,7 +138,7 @@ void loop(void)
     // Take the time, and send it.  This will block until complete
     unsigned long time = millis();
     printf("Now sending %lu...",time);
-    bool ok = radio.write( &time );  
+    bool ok = radio.write( &time, sizeof(unsigned long) );  
     
     // Now, continue listening
     radio.startListening();
@@ -171,7 +159,7 @@ void loop(void)
     {
       // Grab the response, compare, and send to debugging spew
       unsigned long got_time;
-      radio.read( &got_time );
+      radio.read( &got_time, sizeof(unsigned long) );
   
       // Spew it
       printf("Got response %lu, round-trip delay: %lu\n\r",got_time,millis()-got_time);
@@ -182,10 +170,10 @@ void loop(void)
   }
   
   //
-  // Receiver role.  Receive each packet, dump it out, and send it back to the transmitter
+  // Pong back role.  Receive each packet, dump it out, and send it back
   //
   
-  if ( role == role_rx )
+  if ( role == role_pong_back )
   {
     // if there is data ready
     if ( radio.available() )
@@ -196,7 +184,7 @@ void loop(void)
       while (!done)
       {
         // Fetch the payload, and see if this was the last one.
-        done = radio.read( &got_time );
+        done = radio.read( &got_time, sizeof(unsigned long) );
   
         // Spew it
         printf("Got payload %lu...",got_time);
@@ -206,7 +194,7 @@ void loop(void)
       radio.stopListening();
             
       // Send the final one back.
-      radio.write( &got_time );  
+      radio.write( &got_time, sizeof(unsigned long) );  
       printf("Sent response.\n\r");
       
       // Now, resume listening so we catch the next packets.
@@ -214,3 +202,4 @@ void loop(void)
     }
   }
 }
+// vim:ci sts=2 sw=2 ft=cpp