/* 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 /** * Driver for nRF24L01 2.4GHz Wireless Transceiver */ class RF24 { private: int ce_pin; /**< "Chip Enable" pin, activates the RX or TX role */ int csn_pin; /**< SPI Chip select */ int payload_size; /**< Fixed size of payloads */ protected: /** * @name Low-level internal interface. * * Protected methods that address the chip directly. */ /**@{*/ /** * Set chip select pin * * @param mode HIGH to take this unit off the SPI bus, LOW to put it on */ void csn(int mode) ; /** * Set chip enable * * @param mode 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 mode); /** * 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) ; /** * 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) ; /** * 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); /** * 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) ; /**@}*/ public: /** * 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(int _cepin, int _cspin); /** * Begin operation of the chip * * Call this in setup(), before calling any other methods. */ void begin(void); /** * Set RF communication channel * * @param channel Which RF channel to communicate on, 0-127 */ void setChannel(int 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(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) ; /** * Start listening on the pipes opened for reading. * * Be sure to open some pipes for reading first. Do not call 'write' * while in this mode, without first calling 'stopListening'. */ void startListening(void); /** * Stop listening for incoming messages * * Necessary to do this before writing. */ void stopListening(void); /** * Write to the open writing pipe * * 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) ; /** * Test whether there are bytes available to be read * * @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); /** * 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 all 5 reading pipes 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 all pipes must share the top 32 bits * * @param number Which pipe# to open, 1-5. * @param address The 40-bit address of the pipe to open. */ 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. 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. */ /** * @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