/* TwoWire.h - TWI/I2C library for Arduino & Wiring Copyright (c) 2006 Nicholas Zambetti. All right reserved. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts */ #ifndef TwoWire_h #define TwoWire_h #include #include "Arduino.h" #define BUFFER_LENGTH 32 #define WIRE_HAS_END 1 #if defined(__arm__) && defined(CORE_TEENSY) extern "C" void i2c0_isr(void); #endif class TwoWire : public Stream { private: static uint8_t rxBuffer[]; static uint8_t rxBufferIndex; static uint8_t rxBufferLength; static uint8_t txAddress; static uint8_t txBuffer[]; static uint8_t txBufferIndex; static uint8_t txBufferLength; static uint8_t transmitting; static void onRequestService(void); static void onReceiveService(uint8_t*, int); static void (*user_onRequest)(void); static void (*user_onReceive)(int); static void sda_rising_isr(void); #if defined(__arm__) && defined(CORE_TEENSY) static uint8_t sda_pin_num; static uint8_t scl_pin_num; friend void i2c0_isr(void); #endif public: TwoWire(); void begin(); void begin(uint8_t); void begin(int); void end(); void setClock(uint32_t); void setSDA(uint8_t); void setSCL(uint8_t); void beginTransmission(uint8_t); void beginTransmission(int); uint8_t endTransmission(void); uint8_t endTransmission(uint8_t); uint8_t requestFrom(uint8_t, uint8_t); uint8_t requestFrom(uint8_t, uint8_t, uint8_t); uint8_t requestFrom(int, int); uint8_t requestFrom(int, int, int); virtual size_t write(uint8_t); virtual size_t write(const uint8_t *, size_t); virtual int available(void); virtual int read(void); virtual int peek(void); virtual void flush(void); void onReceive( void (*)(int) ); void onRequest( void (*)(void) ); #ifdef CORE_TEENSY // added by Teensyduino installer, for compatibility // with pre-1.0 sketches and libraries void send(uint8_t b) { write(b); } void send(uint8_t *s, uint8_t n) { write(s, n); } void send(int n) { write((uint8_t)n); } void send(char *s) { write(s); } uint8_t receive(void) { int c = read(); if (c < 0) return 0; return c; } #endif inline size_t write(unsigned long n) { return write((uint8_t)n); } inline size_t write(long n) { return write((uint8_t)n); } inline size_t write(unsigned int n) { return write((uint8_t)n); } inline size_t write(int n) { return write((uint8_t)n); } using Print::write; }; extern TwoWire Wire; #if defined(__arm__) && defined(CORE_TEENSY) class TWBRemulation { public: inline TWBRemulation & operator = (int val) __attribute__((always_inline)) { if (val == 12 || val == ((F_CPU / 400000) - 16) / 2) { // 22, 52, 112 I2C0_C1 = 0; #if F_BUS == 120000000 I2C0_F = I2C_F_DIV288; // 416 kHz #elif F_BUS == 108000000 I2C0_F = I2C_F_DIV256; // 422 kHz #elif F_BUS == 96000000 I2C0_F = I2C_F_DIV240; // 400 kHz #elif F_BUS == 90000000 I2C0_F = I2C_F_DIV224; // 402 kHz #elif F_BUS == 80000000 I2C0_F = I2C_F_DIV192; // 416 kHz #elif F_BUS == 72000000 I2C0_F = I2C_F_DIV192; // 375 kHz #elif F_BUS == 64000000 I2C0_F = I2C_F_DIV160; // 400 kHz #elif F_BUS == 60000000 I2C0_F = I2C_F_DIV144; // 416 kHz #elif F_BUS == 56000000 I2C0_F = I2C_F_DIV144; // 389 kHz #elif F_BUS == 54000000 I2C0_F = I2C_F_DIV128; // 422 kHz #elif F_BUS == 48000000 I2C0_F = I2C_F_DIV112; // 400 kHz #elif F_BUS == 40000000 I2C0_F = I2C_F_DIV96; // 416 kHz #elif F_BUS == 36000000 I2C0_F = I2C_F_DIV96; // 375 kHz #elif F_BUS == 24000000 I2C0_F = I2C_F_DIV64; // 375 kHz #elif F_BUS == 16000000 I2C0_F = I2C_F_DIV40; // 400 kHz #elif F_BUS == 8000000 I2C0_F = I2C_F_DIV20; // 400 kHz #elif F_BUS == 4000000 I2C0_F = I2C_F_DIV20; // 200 kHz #elif F_BUS == 2000000 I2C0_F = I2C_F_DIV20; // 100 kHz #endif I2C0_C1 = I2C_C1_IICEN; } else if (val == 72 || val == ((F_CPU / 100000) - 16) / 2) { // 112, 232, 472 I2C0_C1 = 0; #if F_BUS == 120000000 I2C0_F = I2C_F_DIV1152; // 104 kHz #elif F_BUS == 108000000 I2C0_F = I2C_F_DIV1024; // 105 kHz #elif F_BUS == 96000000 I2C0_F = I2C_F_DIV960; // 100 kHz #elif F_BUS == 90000000 I2C0_F = I2C_F_DIV896; // 100 kHz #elif F_BUS == 80000000 I2C0_F = I2C_F_DIV768; // 104 kHz #elif F_BUS == 72000000 I2C0_F = I2C_F_DIV640; // 112 kHz #elif F_BUS == 64000000 I2C0_F = I2C_F_DIV640; // 100 kHz #elif F_BUS == 60000000 I2C0_F = I2C_F_DIV576; // 104 kHz #elif F_BUS == 56000000 I2C0_F = I2C_F_DIV512; // 109 kHz #elif F_BUS == 54000000 I2C0_F = I2C_F_DIV512; // 105 kHz #elif F_BUS == 48000000 I2C0_F = I2C_F_DIV480; // 100 kHz #elif F_BUS == 40000000 I2C0_F = I2C_F_DIV384; // 104 kHz #elif F_BUS == 36000000 I2C0_F = I2C_F_DIV320; // 113 kHz #elif F_BUS == 24000000 I2C0_F = I2C_F_DIV240; // 100 kHz #elif F_BUS == 16000000 I2C0_F = I2C_F_DIV160; // 100 kHz #elif F_BUS == 8000000 I2C0_F = I2C_F_DIV80; // 100 kHz #elif F_BUS == 4000000 I2C0_F = I2C_F_DIV40; // 100 kHz #elif F_BUS == 2000000 I2C0_F = I2C_F_DIV20; // 100 kHz #endif I2C0_C1 = I2C_C1_IICEN; } return *this; } inline operator int () const __attribute__((always_inline)) { #if F_BUS == 120000000 if (I2C0_F == I2C_F_DIV288) return 12; #elif F_BUS == 108000000 if (I2C0_F == I2C_F_DIV256) return 12; #elif F_BUS == 96000000 if (I2C0_F == I2C_F_DIV240) return 12; #elif F_BUS == 90000000 if (I2C0_F == I2C_F_DIV224) return 12; #elif F_BUS == 80000000 if (I2C0_F == I2C_F_DIV192) return 12; #elif F_BUS == 72000000 if (I2C0_F == I2C_F_DIV192) return 12; #elif F_BUS == 64000000 if (I2C0_F == I2C_F_DIV160) return 12; #elif F_BUS == 60000000 if (I2C0_F == I2C_F_DIV144) return 12; #elif F_BUS == 56000000 if (I2C0_F == I2C_F_DIV144) return 12; #elif F_BUS == 54000000 if (I2C0_F == I2C_F_DIV128) return 12; #elif F_BUS == 48000000 if (I2C0_F == I2C_F_DIV112) return 12; #elif F_BUS == 40000000 if (I2C0_F == I2C_F_DIV96) return 12; #elif F_BUS == 36000000 if (I2C0_F == I2C_F_DIV96) return 12; #elif F_BUS == 24000000 if (I2C0_F == I2C_F_DIV64) return 12; #elif F_BUS == 16000000 if (I2C0_F == I2C_F_DIV40) return 12; #elif F_BUS == 8000000 if (I2C0_F == I2C_F_DIV20) return 12; #elif F_BUS == 4000000 if (I2C0_F == I2C_F_DIV20) return 12; #endif return 72; } }; extern TWBRemulation TWBR; #endif #endif