/* * Marlin 3D Printer Firmware * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin] * * Based on Sprinter and grbl. * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * */ #ifndef TWIBUS_H #define TWIBUS_H #include "macros.h" #include <Wire.h> // Print debug messages with M111 S2 (Uses 236 bytes of PROGMEM) //#define DEBUG_TWIBUS typedef void (*twiReceiveFunc_t)(int bytes); typedef void (*twiRequestFunc_t)(); #define TWIBUS_BUFFER_SIZE 32 /** * TWIBUS class * * This class implements a wrapper around the two wire (I2C) bus, it allows * Marlin to send and request data from any slave device on the bus. This is * an experimental feature and it's inner workings as well as public facing * interface are prune to change in the future. * * The two main consumers of this class are M260 and M261, where M260 allows * Marlin to send a I2C packet to a device (please be aware that no repeated * starts are possible), this can be done in caching method by calling multiple * times M260 B<byte-1 value in base 10> or a one liner M260, have a look at * the gcode_M260() function for more information. M261 allows Marlin to * request data from a device, the received data is then relayed into the serial * line for host interpretation. * */ class TWIBus { private: /** * @brief Number of bytes on buffer * @description Number of bytes in the buffer waiting to be flushed to the bus */ uint8_t buffer_s = 0; /** * @brief Internal buffer * @details A fixed buffer. TWI commands can be no longer than this. */ char buffer[TWIBUS_BUFFER_SIZE]; public: /** * @brief Target device address * @description The target device address. Persists until changed. */ uint8_t addr = 0; /** * @brief Class constructor * @details Initialize the TWI bus and clear the buffer */ TWIBus(); /** * @brief Reset the buffer * @details Set the buffer to a known-empty state */ void reset(); /** * @brief Send the buffer data to the bus * @details Flush the buffer to the target address */ void send(); /** * @brief Add one byte to the buffer * @details Add a byte to the end of the buffer. * Silently fails if the buffer is full. * * @param c a data byte */ void addbyte(const char c); /** * @brief Add some bytes to the buffer * @details Add bytes to the end of the buffer. * Concatenates at the buffer size. * * @param src source data address * @param bytes the number of bytes to add */ void addbytes(char src[], uint8_t bytes); /** * @brief Add a null-terminated string to the buffer * @details Add bytes to the end of the buffer up to a nul. * Concatenates at the buffer size. * * @param str source string address */ void addstring(char str[]); /** * @brief Set the target slave address * @details The target slave address for sending the full packet * * @param adr 7-bit integer address */ void address(const uint8_t adr); /** * @brief Prefix for echo to serial * @details Echo a label, length, address, and "data:" * * @param bytes the number of bytes to request */ static void echoprefix(uint8_t bytes, const char prefix[], uint8_t adr); /** * @brief Echo data on the bus to serial * @details Echo some number of bytes from the bus * to serial in a parser-friendly format. * * @param bytes the number of bytes to request */ static void echodata(uint8_t bytes, const char prefix[], uint8_t adr); /** * @brief Echo data in the buffer to serial * @details Echo the entire buffer to serial * to serial in a parser-friendly format. * * @param bytes the number of bytes to request */ void echobuffer(const char prefix[], uint8_t adr); /** * @brief Request data from the slave device and wait. * @details Request a number of bytes from a slave device. * Wait for the data to arrive, and return true * on success. * * @param bytes the number of bytes to request * @return status of the request: true=success, false=fail */ bool request(const uint8_t bytes); /** * @brief Capture data from the bus into the buffer. * @details Capture data after a request has succeeded. * * @param bytes the number of bytes to request * @return the number of bytes captured to the buffer */ uint8_t capture(char *dst, const uint8_t bytes); /** * @brief Flush the i2c bus. * @details Get all bytes on the bus and throw them away. */ static void flush(); /** * @brief Request data from the slave device, echo to serial. * @details Request a number of bytes from a slave device and output * the returned data to serial in a parser-friendly format. * * @param bytes the number of bytes to request */ void relay(const uint8_t bytes); #if I2C_SLAVE_ADDRESS > 0 /** * @brief Register a slave receive handler * @details Set a handler to receive data addressed to us * * @param handler A function to handle receiving bytes */ inline void onReceive(const twiReceiveFunc_t handler) { Wire.onReceive(handler); } /** * @brief Register a slave request handler * @details Set a handler to send data requested from us * * @param handler A function to handle receiving bytes */ inline void onRequest(const twiRequestFunc_t handler) { Wire.onRequest(handler); } /** * @brief Default handler to receive * @details Receive bytes sent to our slave address * and simply echo them to serial. */ void receive(uint8_t bytes); /** * @brief Send a reply to the bus * @details Send the buffer and clear it. * If a string is passed, write it into the buffer first. */ void reply(char str[]=NULL); inline void reply(const char str[]) { this->reply((char*)str); } #endif #if ENABLED(DEBUG_TWIBUS) /** * @brief Prints a debug message * @details Prints a simple debug message "TWIBus::function: value" */ static void prefix(const char func[]); static void debug(const char func[], uint32_t adr); static void debug(const char func[], char c); static void debug(const char func[], char adr[]); static inline void debug(const char func[], uint8_t v) { debug(func, (uint32_t)v); } #endif }; #endif //TWIBUS_H