/* Copyright (C) 2011 James Coliz, Jr. 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. */ #ifndef __RF24_H__ #define __RF24_H__ #include 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; /** * Driver for nRF24L01(+) 2.4GHz Wireless Transceiver */ class RF24 { private: uint8_t ce_pin; /**< "Chip Enable" pin, activates the RX or TX role */ uint8_t csn_pin; /**< SPI Chip select */ boolean wide_band; /* 2Mbs data rate in use? */ boolean p_variant; /* False for RF24L01 and true for RF24L01P */ uint8_t payload_size; /**< Fixed size of payloads */ boolean ack_payload_available; /**< Whether there is an ack payload waiting */ uint8_t ack_payload_length; /**< Dynamic size of pending ack payload. Note: not used. */ uint64_t pipe0_reading_address; /**< Last address set on pipe 0 for reading. */ 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(const int mode) const ; /** * 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(const int level) const ; /** * 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(const uint8_t reg, uint8_t* buf, uint8_t len) const ; /** * 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(const uint8_t reg) const ; /** * 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(const uint8_t reg, const uint8_t* buf, uint8_t len) const ; /** * 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(const uint8_t reg, const uint8_t value) const ; /** * 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) ; /** * Read the payload length * * For dynamic payloads, this pulls the size of the payload off * the chip * * @return Payload length of last-received dynamic payload */ uint8_t read_payload_length(void); /** * Empty the receive buffer * * @return Current value of status register */ uint8_t flush_rx(void) const ; /** * Empty the transmit buffer * * @return Current value of status register */ uint8_t flush_tx(void) const ; /** * Retrieve the current status of the chip * * @return Current value of status register */ uint8_t get_status(void) const ; /** * 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) const ; /** * 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) const ; /** * 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) const ; /**@}*/ 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(const uint8_t _cepin, const uint8_t _cspin) ; /** * Begin operation of the chip * * Call this in setup(), before calling any other methods. */ void begin(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) const ; /** * Stop listening for incoming messages * * Do this before calling write(). */ void stopListening(void) const ; /** * 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 */ boolean 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 */ boolean available(void) const ; /** * 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 */ boolean 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 5 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 * * @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(const uint8_t number, const uint64_t address); /**@}*/ /** * @name Optional public interface * * Methods you may want to use but are not needed for regular operation */ /**@{*/ /** * Set RF communication channel * * @param channel Which RF channel to communicate on, 0-127 in narrow band * and 0 - 63 in wide band. Narrow and wideband is determined by data rate. * A 2Mbs data rate automatically forces wide band mode. */ void setChannel(uint8_t channel); /** * Set 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(const uint8_t size); /** * Get Payload Size * * @see setPayloadSize() * * @return The number of bytes in the payload */ uint8_t getPayloadSize(void) ; /** * 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) const ; /** * Enter low-power mode * * To return to normal power mode, either write() some data or * startListening(). */ void powerDown(void) const ; /** * 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 */ boolean available(uint8_t* pipe_num) const ; /** * 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) const; /** * 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(const uint8_t pipe, const void* buf, uint8_t len) const ; /** * 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. */ boolean isAckPayloadAvailable(void); /** * @return Returns true if the hardware is RF24L01P (or compatible) and false * if its not. */ boolean isPVariant(void) const ; /** * 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(const bool enable) const ; /** * 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 which pipeline to modify * @param enable Whether to enable (true) or disable (false) auto-acks */ void setAutoAck( const uint8_t pipe, const bool enable ) const ; /** * 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 */ boolean testCarrier(void) const ; /** * 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 */ boolean testRPD(void) const ; /** * 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 Desired PA level. */ void setPALevel( const rf24_pa_dbm_e level ) const ; /** * 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 ) const ; /** * Set the transmission data rate * * @param speed RF24_250KBPS for 250kbs, RF24_1MBPS for 1Mbps, or RF24_2MBPS for 2Mbps */ boolean setDataRate(const rf24_datarate_e speed); /** * Set 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 ) const ; /** * Set the CRC length * * @param length RF24_CRC_8 for 8-bit or RF24_CRC_16 for 16-bit */ void setCRCLength(const rf24_crclength_e length) const ; /** * Disable CRC validation * */ void disableCRC( void ) const ; /**@}*/ }; /** * @example led_remote.pde * * This is an example of how to use the RF24 class to control a remote * bank of LED's using buttons on a remote control. * * Every time the buttons change on the remote, the entire state of * buttons is send to the led board, which displays the state. */ /** * @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. * The ping node can then see how long the whole cycle took. */ /** * @example starping.pde * * This sketch is a more complex example of using the RF24 library for Arduino. * Deploy this on up to six nodes. Set one as the 'pong receiver' by tying the * role_pin low, and the others will be 'ping transmit' units. The ping units * unit will send out the value of millis() once a second. The pong unit will * respond back with a copy of the value. Each ping unit can get that response * back, and determine how long the whole cycle took. * * This example requires a bit more complexity to determine which unit is which. * The pong receiver is identified by having its role_pin tied to ground. * The ping senders are further differentiated by a byte in eeprom. */ /** * @example pingpair_pl.pde * * This is an example of how to do two-way communication without changing * transmit/receive modes. Here, a payload is set to the transmitter within * the Ack packet of each transmission. Note that the payload is set BEFORE * the sender's message arrives. */ /** * @example pingpair_sleepy.pde * * This is an example of how to use the RF24 class to create a battery- * efficient system. It is just like the pingpair.pde example, but the * ping node powers down the radio and sleeps the MCU after every * ping/pong cycle. */ /** * @example starping_relay.pde * * This sketch is a very complex example of using the RF24 library for Arduino. * Deploy this on any number of nodes to create a basic mesh network. I have * tested this on 6 nodes, but it should work on many more. 'Leaf' nodes attempt * to send a ping every 2 seconds to the 'Base' node. Optional 'Relay' nodes * will relay these transmissions. */ /** * @example scanner.pde * * Example to detect interference on the various channels available. * This is a good diagnostic tool to check whether you're picking a * good channel for your application. * * Inspired by cpixip. * See http://arduino.cc/forum/index.php/topic,54795.0.html */ /** * @mainpage Driver for nRF24L01(+) 2.4GHz Wireless Transceiver * * Design Goals: This library is designed to be... * @li Maximally compliant with the intended operation of the chip * @li Easy for beginners to use * @li Consumed with a public interface that's similiar to other Arduino standard libraries * @li Built against the standard SPI library. * * Please refer to: * * @li Documentation Main Page * @li RF24 Class Documentation * @li Source Code * @li Downloads Page * @li Chip Datasheet * * 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. */ #endif // __RF24_H__ // vim:ai:cin:sts=2 sw=2 ft=cpp