以前紹介したライブラリの改良版を作成してみた。
クラス名変更と標準Wireクラスの準互換ラッパークラスを追加。１６ＭＨｚ動作で最大１ＭＢＰＳ弱の速度がでるのに加えプルアップ抵抗が必要ないのでちょっとした実験などにも便利に使えると思う。
省メモリ重視ならSimpleWireクラスを直接使い、Arduinoの互換性重視ならTwoWireクラスをインスタンス化して使えば良いだろう。
ちなみにTwoWireクラスはArduino標準Wireライブラリのクラス名と同じであることに注意すべし。同じ名前にする必要もなかったのだが名前考えるが面倒だったのでついつい．．．
【仕様】
・SDA/SCLは任意のピンに割当可能。（プルアップ抵抗なしでＯＫ）
・クロックは100KHz/400KHz/1MHzに対応。
・７ビットアドレスのみ対応。
・転送データ長は最大255バイト。
・シングル・マスターモード専用。（アービトレーションなし）
・リピーテッド・スタート非対応。（シングルマスターモード専用なのでそもそも意味がない）
・クロック・ストレッチ非対応。（速度優先）
【ライブラリ】
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/* SimpleWire.h - I2C Single Master Mode Library for AVR Copyright (c) 2020 Sasapea's Lab. All right reserved. exsample: #define SimpleWire_SCL_PORT B #define SimpleWire_SCL_POS 1 #define SimpleWire_SDA_PORT B #define SimpleWire_SDA_POS 3 #include "SimpleWire.h" #define SIMPLEWIRE SimpleWire<SimpleWire_100K> #define SLAVE_ADDR 0x20 void setup() { SIMPLEWIRE::begin(); } void loop() { uint8_t len, buf[32]; ... // write if (SIMPLEWIRE::write(SLAVE_ADDR, buf, len) != (int)len) // error ... // read if (SIMPLEWIRE::read(SLAVE_ADDR, buf, len) != (int)len) // error ... // device scan for (uint8_t addr = 0x08; addr <= 0x7F; ++addr) { if (SIMPLEWIRE::write(addr, 0, 0) == 0) // device found. } 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifndef __SIMPLEWIRE_H #define __SIMPLEWIRE_H #include <stdint.h> #include <stdbool.h> #include <avr/io.h> #include <util/delay_basic.h> #ifndef SimpleWire_HS_MODE #define SimpleWire_HS_MODE 1 #endif #define SimpleWire_100K 0 #define SimpleWire_400K 1 #define SimpleWire_1M 2 #define SimpleWire_WRITE 0 #define SimpleWire_READ 1 #define SimpleWire_CAT(a, b) a##b #define SimpleWire_REG(r, p) SimpleWire_CAT(r, p) #define SimpleWire_SCL(r) SimpleWire_REG(r, SimpleWire_SCL_PORT) #define SimpleWire_SDA(r) SimpleWire_REG(r, SimpleWire_SDA_PORT) #if SimpleWire_HS_MODE #define SimpleWire_SCL_INIT #define SimpleWire_SCL_HIGH do { \ cli(); \ SimpleWire_SCL(PORT) |= _BV(SimpleWire_SCL_POS); \ SimpleWire_SCL(DDR ) &= ~_BV(SimpleWire_SCL_POS); \ sei(); \ } while (0) #define SimpleWire_SCL_LOW do { \ cli(); \ SimpleWire_SCL(PORT) &= ~_BV(SimpleWire_SCL_POS); \ SimpleWire_SCL(DDR ) |= _BV(SimpleWire_SCL_POS); \ sei(); \ } while (0); #define SimpleWire_SDA_INIT #define SimpleWire_SDA_HIGH do { \ cli(); \ SimpleWire_SDA(PORT) |= _BV(SimpleWire_SDA_POS); \ SimpleWire_SDA(DDR ) &= ~_BV(SimpleWire_SDA_POS); \ sei(); \ } while (0) #define SimpleWire_SDA_LOW do { \ cli(); \ SimpleWire_SDA(PORT) &= ~_BV(SimpleWire_SDA_POS); \ SimpleWire_SDA(DDR ) |= _BV(SimpleWire_SDA_POS); \ sei(); \ } while (0) #else #define SimpleWire_SCL_INIT SimpleWire_SCL(PORT) &= ~_BV(SimpleWire_SCL_POS) #define SimpleWire_SCL_HIGH SimpleWire_SCL(DDR) &= ~_BV(SimpleWire_SCL_POS) #define SimpleWire_SCL_LOW SimpleWire_SCL(DDR) |= _BV(SimpleWire_SCL_POS) #define SimpleWire_SDA_INIT SimpleWire_SDA(PORT) &= ~_BV(SimpleWire_SDA_POS) #define SimpleWire_SDA_HIGH SimpleWire_SDA(DDR) &= ~_BV(SimpleWire_SDA_POS) #define SimpleWire_SDA_LOW SimpleWire_SDA(DDR) |= _BV(SimpleWire_SDA_POS) #endif #define SimpleWire_SDA_READ (SimpleWire_SDA(PIN) & _BV(SimpleWire_SDA_POS)) #define SimpleWire_DELAY(t) \ do { \ uint8_t n = (uint8_t)((((t) / 1000.0) * (F_CPU / 1000000) * 256) / 768); \ if (n) _delay_loop_1(n); \ } while (0) // // Standard Mode // #define SimpleWire_100K_THDSTA SimpleWire_DELAY(4000) // 4000 #define SimpleWire_100K_TLOW SimpleWire_DELAY(4400) // 4700 #define SimpleWire_100K_THIGH SimpleWire_DELAY(4000) // 4000 #define SimpleWire_100K_TSUSTA SimpleWire_DELAY(4700) // 4700 #define SimpleWire_100K_THDDAT SimpleWire_DELAY( 200) // 300 #define SimpleWire_100K_TSUSTO SimpleWire_DELAY(4000) // 4000 #define SimpleWire_100K_TSUDAT SimpleWire_DELAY( 200) // 250 #define SimpleWire_100K_TBUF SimpleWire_DELAY(4700) // 4700 // // Fast Mode // #define SimpleWire_400K_THDSTA // 600 #define SimpleWire_400K_TLOW SimpleWire_DELAY( 800) // 1300 #define SimpleWire_400K_THIGH SimpleWire_DELAY( 200) // 600 #define SimpleWire_400K_TSUSTA SimpleWire_DELAY( 600) // 600 #define SimpleWire_400K_THDDAT // 0 #define SimpleWire_400K_TSUSTO SimpleWire_DELAY( 400) // 600 #define SimpleWire_400K_TSUDAT // 100 #define SimpleWire_400K_TBUF SimpleWire_DELAY(1300) // 1300 // // Hs Mode // #define SimpleWire_1M_THDSTA // 160 #define SimpleWire_1M_TLOW // 160 #define SimpleWire_1M_THIGH // 60 #define SimpleWire_1M_TSUSTA // 160 #define SimpleWire_1M_THDDAT // 0 #define SimpleWire_1M_TSUSTO // 160 #define SimpleWire_1M_TSUDAT // 10 #define SimpleWire_1M_TBUF // 60 #define SimpleWire_DELAY_THDSTA(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_THDSTA; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_THDSTA; \ else SimpleWire_100K_THDSTA; \ } while (0) #define SimpleWire_DELAY_TLOW(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_TLOW; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_TLOW; \ else SimpleWire_100K_TLOW; \ } while (0) #define SimpleWire_DELAY_THIGH(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_THIGH; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_THIGH; \ else SimpleWire_100K_THIGH; \ } while (0) #define SimpleWire_DELAY_TSUSTA(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_TSUSTA; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_TSUSTA; \ else SimpleWire_100K_TSUSTA; \ } while (0) #define SimpleWire_DELAY_THDDAT(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_THDDAT; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_THDDAT; \ else SimpleWire_100K_THDDAT; \ } while (0) #define SimpleWire_DELAY_TSUSTO(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_TSUSTO; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_TSUSTO; \ else SimpleWire_100K_TSUSTO; \ } while (0) #define SimpleWire_DELAY_TSUDAT(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_TSUDAT; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_TSUDAT; \ else SimpleWire_100K_TSUDAT; \ } while (0) #define SimpleWire_DELAY_TBUF(m) \ do { \ if ((m) == SimpleWire_1M ) SimpleWire_1M_TBUF; \ else if ((m) == SimpleWire_400K) SimpleWire_400K_TBUF; \ else SimpleWire_100K_TBUF; \ } while (0) template<uint8_t MODE = SimpleWire_100K> class SimpleWire { private: static void start(void) { SimpleWire_SDA_LOW; SimpleWire_DELAY_THDSTA(MODE); SimpleWire_SCL_LOW; SimpleWire_DELAY_THDDAT(MODE); } static void stop(void) { SimpleWire_SDA_LOW; SimpleWire_DELAY_TLOW(MODE); SimpleWire_SCL_HIGH; SimpleWire_DELAY_TSUSTO(MODE); SimpleWire_SDA_HIGH; SimpleWire_DELAY_TBUF(MODE); } static uint8_t write(uint8_t b) { for (uint8_t i = 0x80; i; i >>= 1) { if (b & i) SimpleWire_SDA_HIGH; else SimpleWire_SDA_LOW; SimpleWire_DELAY_TLOW(MODE); SimpleWire_SCL_HIGH; SimpleWire_DELAY_THIGH(MODE); SimpleWire_SCL_LOW; SimpleWire_DELAY_THDDAT(MODE); } SimpleWire_SDA_HIGH; SimpleWire_DELAY_TLOW(MODE); SimpleWire_SCL_HIGH; SimpleWire_DELAY_THIGH(MODE); b = SimpleWire_SDA_READ; SimpleWire_SCL_LOW; SimpleWire_DELAY_THDDAT(MODE); return b; } static uint8_t read(void) { uint8_t b = 0; SimpleWire_SDA_HIGH; for (uint8_t i = 0x80; i; i >>= 1) { SimpleWire_DELAY_TLOW(MODE); SimpleWire_SCL_HIGH; SimpleWire_DELAY_THIGH(MODE); if (SimpleWire_SDA_READ) b |= i; SimpleWire_SCL_LOW; SimpleWire_DELAY_THDDAT(MODE); } SimpleWire_SDA_LOW; SimpleWire_DELAY_TLOW(MODE); SimpleWire_SCL_HIGH; SimpleWire_DELAY_THIGH(MODE); SimpleWire_SCL_LOW; SimpleWire_DELAY_THDDAT(MODE); return b; } public: SimpleWire(void) { } virtual ~SimpleWire(void) { } static void begin(void) { SimpleWire_SCL_INIT; SimpleWire_SCL_HIGH; SimpleWire_SDA_INIT; SimpleWire_SDA_HIGH; } static int write(uint8_t addr, const uint8_t *buf, uint8_t len) { int cnt = -1; // start start(); // write slave address if (write((addr << 1) | SimpleWire_WRITE) == 0) { // write data for (cnt = 0; cnt < len; ++cnt) { if (write(*buf++)) break; } } // stop stop(); return cnt; } static int read(uint8_t addr, uint8_t *buf, uint8_t len) { int cnt = -1; // start start(); // write slave address if (write((addr << 1) | SimpleWire_READ) == 0) { // read data for (cnt = 0; cnt < len; ++cnt) *buf++ = read(); } // stop stop(); return cnt; } }; template<uint8_t MODE = SimpleWire_100K, uint8_t BUFFER_LENGTH = 32> class TwoWire { private: uint8_t _buffer[BUFFER_LENGTH]; uint8_t _count; uint8_t _index; uint8_t _error; uint8_t _addr; public: TwoWire(void) : _count(0) , _index(0) , _error(0) , _addr(0) { } virtual ~TwoWire(void) { } void begin(void) { SimpleWire<MODE>::begin(); } void end(void) { } void beginTransmission(uint8_t address) { _addr = address; _count = 0; _index = 0; _error = 0; } void beginTransmission(int address) { beginTransmission((uint8_t)address); } uint8_t endTransmission(uint8_t sendStop = true) { if (_error) return 1; // buffer overflow int rv = SimpleWire<MODE>::write(_addr, _buffer, _index); if (rv == _index) return 0; // success return (rv < 0 ? 2 : 3); } uint8_t requestFrom(uint8_t address, uint8_t quantity) { return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)true); } uint8_t requestFrom(uint8_t address, uint8_t quantity, uint8_t sendStop) { return requestFrom((uint8_t)address, (uint8_t)quantity, (uint32_t)0, (uint8_t)0, (uint8_t)sendStop); } uint8_t requestFrom(int address, int quantity) { return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)true); } uint8_t requestFrom(int address, int quantity, int sendStop) { return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)sendStop); } uint8_t requestFrom(uint8_t address, uint8_t quantity, uint32_t iaddress, uint8_t isize, uint8_t sendStop) { if (isize > 0) { // send internal address; this mode allows sending a repeated start to access // some devices' internal registers. This function is executed by the hardware // TWI module on other processors (for example Due's TWI_IADR and TWI_MMR registers) beginTransmission(address); // the maximum size of internal address is 3 bytes if (isize > 3) isize = 3; // write internal register address - most significant byte first switch (isize) { case 3: write((uint8_t)(iaddress >> 16)); case 2: write((uint8_t)(iaddress >> 8)); case 1: write((uint8_t)(iaddress >> 0)); break; } endTransmission(false); } // clamp to buffer length if (quantity > BUFFER_LENGTH) quantity = BUFFER_LENGTH; // perform blocking read into buffer int read = SimpleWire<MODE>::read(address, _buffer, quantity); // set rx buffer iterator vars _count = read > 0 ? (uint8_t)read : 0; _index = 0; return _count; } virtual size_t write(uint8_t data) { // don't bother if buffer is full if (_index == 0xFF) { _error = 1; return 0; } // put byte in tx buffer _buffer[_index++] = data; return 1; } virtual size_t write(uint8_t *data, uint8_t len) { uint8_t cnt = 0; while (len--) cnt += write(*data++); return cnt; } virtual int available(void) { return (_index < _count ? _count - _index : 0); } virtual int read(void) { int value = -1; // get each successive byte on each call if(_index < _count) value = _buffer[_index++]; return value; } virtual int peek(void) { int value = -1; if (_index < _count) value = _buffer[_index]; return value; } virtual void flush(void) { } 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); } }; #endif |