File content as of revision 4:491267614a10:

/*
    Copyright (c) 2007 Stefan Engelke <mbox@stefanengelke.de>

    Permission is hereby granted, free of charge, to any person 
    obtaining a copy of this software and associated documentation 
    files (the "Software"), to deal in the Software without 
    restriction, including without limitation the rights to use, copy, 
    modify, merge, publish, distribute, sublicense, and/or sell copies 
    of the Software, and to permit persons to whom the Software is 
    furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be 
    included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
    DEALINGS IN THE SOFTWARE.
*/

/* Memory Map */
#define CONFIG      0x00
#define EN_AA       0x01
#define EN_RXADDR   0x02
#define SETUP_AW    0x03
#define SETUP_RETR  0x04
#define RF_CH       0x05
#define RF_SETUP    0x06
#define STATUS      0x07
#define OBSERVE_TX  0x08
#define CD          0x09
#define RX_ADDR_P0  0x0A
#define RX_ADDR_P1  0x0B
#define RX_ADDR_P2  0x0C
#define RX_ADDR_P3  0x0D
#define RX_ADDR_P4  0x0E
#define RX_ADDR_P5  0x0F
#define TX_ADDR     0x10
#define RX_PW_P0    0x11
#define RX_PW_P1    0x12
#define RX_PW_P2    0x13
#define RX_PW_P3    0x14
#define RX_PW_P4    0x15
#define RX_PW_P5    0x16
#define FIFO_STATUS 0x17
#define DYNPD       0x1C
#define FEATURE     0x1D

/* Bit Mnemonics */
#define MASK_RX_DR  6
#define MASK_TX_DS  5
#define MASK_MAX_RT 4
#define EN_CRC      3
#define CRCO        2
#define PWR_UP      1
#define PRIM_RX     0
#define ENAA_P5     5
#define ENAA_P4     4
#define ENAA_P3     3
#define ENAA_P2     2
#define ENAA_P1     1
#define ENAA_P0     0
#define ERX_P5      5
#define ERX_P4      4
#define ERX_P3      3
#define ERX_P2      2
#define ERX_P1      1
#define ERX_P0      0
#define AW          0
#define ARD         4
#define ARC         0
#define PLL_LOCK    4
#define RF_DR       3
#define RF_PWR      6
#define RX_DR       6
#define TX_DS       5
#define MAX_RT      4
#define RX_P_NO     1
#define TX_FULL     0
#define PLOS_CNT    4
#define ARC_CNT     0
#define TX_REUSE    6
#define FIFO_FULL   5
#define TX_EMPTY    4
#define RX_FULL     1
#define RX_EMPTY    0
#define DPL_P5      5
#define DPL_P4      4
#define DPL_P3      3
#define DPL_P2      2
#define DPL_P1      1
#define DPL_P0      0
#define EN_DPL      2
#define EN_ACK_PAY  1
#define EN_DYN_ACK  0

/* Instruction Mnemonics */
#define R_REGISTER    0x00
#define W_REGISTER    0x20
#define REGISTER_MASK 0x1F
#define ACTIVATE      0x50
#define R_RX_PL_WID   0x60
#define R_RX_PAYLOAD  0x61
#define W_TX_PAYLOAD  0xA0
#define W_ACK_PAYLOAD 0xA8
#define FLUSH_TX      0xE1
#define FLUSH_RX      0xE2
#define REUSE_TX_PL   0xE3
#define NOP           0xFF

/* Non-P omissions */
#define LNA_HCURR   0

/* P model memory Map */
#define RPD         0x09

/* P model bit Mnemonics */
#define RF_DR_LOW   5
#define RF_DR_HIGH  3
#define RF_PWR_LOW  1
#define RF_PWR_HIGH 2

#define HIGH        1
#define LOW         0
#define _BV(n) (1 << n)

/*
 Copyright (C) 2011 J. Coliz <maniacbug@ymail.com>

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 version 2 as published by the Free Software Foundation.
 */

/**
 * @file RF24.h
 *
 * Class declaration for RF24 and helper enums
 */

#ifndef __RF24_H__
#define __RF24_H__

#include <mbed.h>

/**
 * Power Amplifier level.
 *
 * For use with setPALevel()
 */
typedef enum { RF24_PA_MIN = 0,RF24_PA_LOW, RF24_PA_HIGH, RF24_PA_MAX, RF24_PA_ERROR } rf24_pa_dbm_e ;

/**
 * Data rate.  How fast data moves through the air.
 *
 * For use with setDataRate()
 */
typedef enum { RF24_1MBPS = 0, RF24_2MBPS, RF24_250KBPS } rf24_datarate_e;

/**
 * CRC Length.  How big (if any) of a CRC is included.
 *
 * For use with setCRCLength()
 */
typedef enum { RF24_CRC_DISABLED = 0, RF24_CRC_8, RF24_CRC_16 } rf24_crclength_e;

/**
 * Driver for nRF24L01(+) 2.4GHz Wireless Transceiver
 */

class RF24
{
private:
  DigitalOut ce_pin; /**< "Chip Enable" pin, activates the RX or TX role */
  DigitalOut csn_pin; /**< SPI Chip select */
  bool wide_band; /* 2Mbs data rate in use? */
  bool p_variant; /* False for RF24L01 and true for RF24L01P */
  uint8_t payload_size; /**< Fixed size of payloads */
  bool ack_payload_available; /**< Whether there is an ack payload waiting */
  bool dynamic_payloads_enabled; /**< Whether dynamic payloads are enabled. */ 
  uint8_t ack_payload_length; /**< Dynamic size of pending ack payload. */
  uint64_t pipe0_reading_address; /**< Last address set on pipe 0 for reading. */
  SPI spi;
  Timer mainTimer;

protected:
  /**
   * @name Low-level internal interface.
   *
   *  Protected methods that address the chip directly.  Regular users cannot
   *  ever call these.  They are documented for completeness and for developers who
   *  may want to extend this class.
   */
  /**@{*/

  /**
   * Set chip select pin
   *
   * Running SPI bus at PI_CLOCK_DIV2 so we don't waste time transferring data
   * and best of all, we make use of the radio's FIFO buffers. A lower speed
   * means we're less likely to effectively leverage our FIFOs and pay a higher
   * AVR runtime cost as toll.
   *
   * @param mode HIGH to take this unit off the SPI bus, LOW to put it on
   */
  void csn(int mode);

  /**
   * Set chip enable
   *
   * @param level HIGH to actively begin transmission or LOW to put in standby.  Please see data sheet
   * for a much more detailed description of this pin.
   */
  void ce(int level);  


  /**
   * Read a chunk of data in from a register
   *
   * @param reg Which register. Use constants from nRF24L01.h
   * @param buf Where to put the data
   * @param len How many bytes of data to transfer
   * @return Current value of status register
   */
  uint8_t read_register(uint8_t reg, uint8_t* buf, uint8_t len);

  /**
   * Read single byte from a register
   *
   * @param reg Which register. Use constants from nRF24L01.h
   * @return Current value of register @p reg
   */
  uint8_t read_register(uint8_t reg);

  /**
   * Write a chunk of data to a register
   *
   * @param reg Which register. Use constants from nRF24L01.h
   * @param buf Where to get the data
   * @param len How many bytes of data to transfer
   * @return Current value of status register
   */
  uint8_t write_register(uint8_t reg, const uint8_t* buf, uint8_t len);

  /**
   * Write a single byte to a register
   *
   * @param reg Which register. Use constants from nRF24L01.h
   * @param value The new value to write
   * @return Current value of status register
   */
  uint8_t write_register(uint8_t reg, uint8_t value);

  /**
   * Write the transmit payload
   *
   * 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 len);

  /**
   * Read the receive payload
   *
   * 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 len);



  /**
   * Retrieve the current status of the chip
   *
   * @return Current value of status register
   */
  uint8_t get_status(void);

  /**
   * Decode and print the given status to stdout
   *
   * @param status Status value to print
   *
   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
   */
  void print_status(uint8_t status);

  /**
   * Decode and print the given 'observe_tx' value to stdout
   *
   * @param value The observe_tx value to print
   *
   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
   */
  void print_observe_tx(uint8_t value);

  /**
   * Print the name and value of an 8-bit register to stdout
   *
   * Optionally it can print some quantity of successive
   * registers on the same line.  This is useful for printing a group
   * of related registers on one line.
   *
   * @param name Name of the register
   * @param reg Which register. Use constants from nRF24L01.h
   * @param qty How many successive registers to print
   */
  void print_byte_register(const char* name, uint8_t reg, uint8_t qty = 1);

  /**
   * Print the name and value of a 40-bit address register to stdout
   *
   * Optionally it can print some quantity of successive
   * registers on the same line.  This is useful for printing a group
   * of related registers on one line.
   *
   * @param name Name of the register
   * @param reg Which register. Use constants from nRF24L01.h
   * @param qty How many successive registers to print
   */
  void print_address_register(const char* name, uint8_t reg, uint8_t qty = 1);

  /**
   * Turn on or off the special features of the chip
   *
   * The chip has certain 'features' which are only available when the 'features'
   * are enabled.  See the datasheet for details.
   */
  void toggle_features(void);
  /**@}*/

public:
  /**
   * @name Primary public interface
   *
   *  These are the main methods you need to operate the chip
   */
  /**@{*/

  /**
   * 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.
   *
   * @param _cepin The pin attached to Chip Enable on the RF module
   * @param _cspin The pin attached to Chip Select
   */
  RF24(PinName mosi, PinName miso, PinName sck, PinName _csnpin, PinName _cepin);

  /**
   * Begin operation of the chip
   *
   * Call this in setup(), before calling any other methods.
   */
  void begin(void);
  
    
  /**
   * Empty the receive buffer
   *
   * @return Current value of status register
   */
  uint8_t flush_rx(void);

  /**
   * Empty the transmit buffer
   *
   * @return Current value of status register
   */
  uint8_t flush_tx(void);

  /**
   * Start listening on the pipes opened for reading.
   *
   * Be sure to call openReadingPipe() first.  Do not call write() while
   * in this mode, without first calling stopListening().  Call
   * isAvailable() to check for incoming traffic, and read() to get it.
   */
  void startListening(void);

  /**
   * Stop listening for incoming messages
   *
   * Do this before calling write().
   */
  void stopListening(void);

  /**
   * Write to the open writing pipe
   *
   * Be sure to call openWritingPipe() first to set the destination
   * of where to write to.
   *
   * This blocks until the message is successfully acknowledged by
   * the receiver or the timeout/retransmit maxima are reached.  In
   * the current configuration, the max delay here is 60ms.
   *
   * 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
   */
  bool write( const void* buf, uint8_t len );

  /**
   * Test whether there are bytes available to be read
   *
   * @return True if there is a payload available, false if none is
   */
  bool available(void);

  /**
   * Read the payload
   *
   * Return the last payload received
   *
   * The size of data read is the fixed payload size, see getPayloadSize()
   *
   * @note I specifically chose 'void*' as a data type to make it easier
   * 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
   */
  bool read( void* buf, uint8_t len );

  /**
   * Open a pipe for writing
   *
   * Only one pipe can be open at once, but you can change the pipe
   * you'll listen to.  Do not call this while actively listening.
   * Remember to stopListening() first.
   *
   * Addresses are 40-bit hex values, e.g.:
   *
   * @code
   *   openWritingPipe(0xF0F0F0F0F0);
   * @endcode
   *
   * @param address The 40-bit address of the pipe to open.  This can be
   * any value whatsoever, as long as you are the only one writing to it
   * and only one other radio is listening to it.  Coordinate these pipe
   * addresses amongst nodes on the network.
   */
  void openWritingPipe(uint64_t address);

  /**
   * Open a pipe for reading
   *
   * Up to 6 pipes can be open for reading at once.  Open all the
   * reading pipes, and then call startListening().
   *
   * @see openWritingPipe
   *
   * @warning Pipes 1-5 should share the first 32 bits.
   * Only the least significant byte should be unique, e.g.
   * @code
   *   openReadingPipe(1,0xF0F0F0F0AA);
   *   openReadingPipe(2,0xF0F0F0F066);
   * @endcode
   *
   * @warning Pipe 0 is also used by the writing pipe.  So if you open
   * pipe 0 for reading, and then startListening(), it will overwrite the
   * writing pipe.  Ergo, do an openWritingPipe() again before write().
   *
   * @todo Enforce the restriction that pipes 1-5 must share the top 32 bits
   *
   * @param number Which pipe# to open, 0-5.
   * @param address The 40-bit address of the pipe to open.
   */
  void openReadingPipe(uint8_t number, uint64_t address);

  /**@}*/
  /**
   * @name Optional Configurators 
   *
   *  Methods you can use to get or set the configuration of the chip.
   *  None are required.  Calling begin() sets up a reasonable set of
   *  defaults.
   */
  /**@{*/
  /**
   * Set the number and delay of retries upon failed submit
   *
   * @param delay How long to wait between each retry, in multiples of 250us,
   * max is 15.  0 means 250us, 15 means 4000us.
   * @param count How many retries before giving up, max 15
   */
  void setRetries(uint8_t delay, uint8_t count);

  /**
   * Set RF communication channel
   *
   * @param channel Which RF channel to communicate on, 0-127
   */
  void setChannel(uint8_t channel);

  /**
   * Set Static Payload Size
   *
   * This implementation uses a pre-stablished fixed payload size for all
   * transmissions.  If this method is never called, the driver will always
   * transmit the maximum payload size (32 bytes), no matter how much
   * was sent to write().
   *
   * @todo Implement variable-sized payloads feature
   *
   * @param size The number of bytes in the payload
   */
  void setPayloadSize(uint8_t size);

  /**
   * Get Static Payload Size
   *
   * @see setPayloadSize()
   *
   * @return The number of bytes in the payload
   */
  uint8_t getPayloadSize(void);

  /**
   * Get Dynamic Payload Size
   *
   * For dynamic payloads, this pulls the size of the payload off
   * the chip
   *
   * @return Payload length of last-received dynamic payload
   */
  uint8_t getDynamicPayloadSize(void);
  
  /**
   * Enable custom payloads on the acknowledge packets
   *
   * Ack payloads are a handy way to return data back to senders without
   * manually changing the radio modes on both units.
   *
   * @see examples/pingpair_pl/pingpair_pl.pde
   */
  void enableAckPayload(void);

  /**
   * Enable dynamically-sized payloads
   *
   * This way you don't always have to send large packets just to send them
   * once in a while.  This enables dynamic payloads on ALL pipes.
   *
   * @see examples/pingpair_pl/pingpair_dyn.pde
   */
  void enableDynamicPayloads(void);

  /**
   * Determine whether the hardware is an nRF24L01+ or not.
   *
   * @return true if the hardware is nRF24L01+ (or compatible) and false
   * if its not.
   */
  bool isPVariant(void) ;

  /**
   * Enable or disable auto-acknowlede packets
   *
   * This is enabled by default, so it's only needed if you want to turn
   * it off for some reason.
   *
   * @param enable Whether to enable (true) or disable (false) auto-acks
   */
  void setAutoAck(bool enable);

  /**
   * Enable or disable auto-acknowlede packets on a per pipeline basis.
   *
   * AA is enabled by default, so it's only needed if you want to turn
   * it off/on for some reason on a per pipeline basis.
   *
   * @param pipe Which pipeline to modify
   * @param enable Whether to enable (true) or disable (false) auto-acks
   */
  void setAutoAck( uint8_t pipe, bool enable ) ;

  /**
   * Set Power Amplifier (PA) level to one of four levels.
   * Relative mnemonics have been used to allow for future PA level
   * changes. According to 6.5 of the nRF24L01+ specification sheet,
   * they translate to: RF24_PA_MIN=-18dBm, RF24_PA_LOW=-12dBm,
   * RF24_PA_MED=-6dBM, and RF24_PA_HIGH=0dBm.
   *
   * @param level Desired PA level.
   */
  void setPALevel( rf24_pa_dbm_e level ) ;

  /**
   * Fetches the current PA level.
   *
   * @return Returns a value from the rf24_pa_dbm_e enum describing
   * the current PA setting. Please remember, all values represented
   * by the enum mnemonics are negative dBm. See setPALevel for
   * return value descriptions.
   */
  rf24_pa_dbm_e getPALevel( void ) ;

  /**
   * Set the transmission data rate
   *
   * @warning setting RF24_250KBPS will fail for non-plus units
   *
   * @param speed RF24_250KBPS for 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS for 2Mbps
   * @return true if the change was successful
   */
  bool setDataRate(rf24_datarate_e speed);
  
  /**
   * Fetches the transmission data rate
   *
   * @return Returns the hardware's currently configured datarate. The value
   * is one of 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS, as defined in the
   * rf24_datarate_e enum.
   */
  rf24_datarate_e getDataRate( void ) ;

  /**
   * Set the CRC length
   *
   * @param length RF24_CRC_8 for 8-bit or RF24_CRC_16 for 16-bit
   */
  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
   *
   */
  void disableCRC( void ) ;

  /**@}*/
  /**
   * @name Advanced Operation 
   *
   *  Methods you can use to drive the chip in more advanced ways 
   */
  /**@{*/

  /**
   * Print a giant block of debugging information to stdout
   *
   * @warning Does nothing if stdout is not defined.  See fdevopen in stdio.h
   */
  void printDetails(void);

  /**
   * Enter low-power mode
   *
   * To return to normal power mode, either write() some data or
   * startListening, or powerUp().
   */
  void powerDown(void);

  /**
   * Leave low-power mode - making radio more responsive
   *
   * To return to low power mode, call powerDown().
   */
  void powerUp(void) ;

  /**
   * Test whether there are bytes available to be read
   *
   * Use this version to discover on which pipe the message
   * arrived.
   *
   * @param[out] pipe_num Which pipe has the payload available
   * @return True if there is a payload available, false if none is
   */
  bool available(uint8_t* pipe_num);

  /**
   * Non-blocking write to the open writing pipe
   *
   * Just like write(), but it returns immediately. To find out what happened
   * to the send, catch the IRQ and then call whatHappened().
   *
   * @see write()
   * @see whatHappened()
   *
   * @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
   */
  void startWrite( const void* buf, uint8_t len );

  /**
   * Write an ack payload for the specified pipe
   *
   * The next time a message is received on @p pipe, the data in @p buf will
   * be sent back in the acknowledgement.
   *
   * @warning According to the data sheet, only three of these can be pending
   * at any time.  I have not tested this.
   *
   * @param pipe Which pipe# (typically 1-5) will get this response.
   * @param buf Pointer to data that is sent
   * @param len Length of the data to send, up to 32 bytes max.  Not affected
   * by the static payload set by setPayloadSize().
   */
  void writeAckPayload(uint8_t pipe, const void* buf, uint8_t len);

  /**
   * Determine if an ack payload was received in the most recent call to
   * write().
   *
   * Call read() to retrieve the ack payload.
   *
   * @warning Calling this function clears the internal flag which indicates
   * a payload is available.  If it returns true, you must read the packet
   * out as the very next interaction with the radio, or the results are
   * undefined.
   *
   * @return True if an ack payload is available.
   */
  bool isAckPayloadAvailable(void);

  /**
   * Call this when you get an interrupt to find out why
   *
   * Tells you what caused the interrupt, and clears the state of
   * interrupts.
   *
   * @param[out] tx_ok The send was successful (TX_DS)
   * @param[out] tx_fail The send failed, too many retries (MAX_RT)
   * @param[out] rx_ready There is a message waiting to be read (RX_DS)
   */
  void whatHappened(bool& tx_ok,bool& tx_fail,bool& rx_ready);

  /**
   * Test whether there was a carrier on the line for the
   * previous listening period.
   *
   * Useful to check for interference on the current channel.
   *
   * @return true if was carrier, false if not
   */
  bool testCarrier(void);

  /**
   * Test whether a signal (carrier or otherwise) greater than
   * or equal to -64dBm is present on the channel. Valid only
   * on nRF24L01P (+) hardware. On nRF24L01, use testCarrier().
   *
   * Useful to check for interference on the current channel and
   * channel hopping strategies.
   *
   * @return true if signal => -64dBm, false if not
   */
  bool testRPD(void) ;
  
  uint8_t min(uint8_t, uint8_t);
};


#endif // __RF24_H__
// vim:ai:cin:sts=2 sw=2 ft=cpp