136 lines
4.5 KiB
C++
136 lines
4.5 KiB
C++
/*
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I2C.h - I2C library
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Copyright (c) 2011-2012 Wayne Truchsess. All right reserved.
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Rev 5.0 - January 24th, 2012
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- Removed the use of interrupts completely from the library
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so TWI state changes are now polled.
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- Added calls to lockup() function in most functions
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to combat arbitration problems
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- Fixed scan() procedure which left timeouts enabled
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and set to 80msec after exiting procedure
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- Changed scan() address range back to 0 - 0x7F
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- Removed all Wire legacy functions from library
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- A big thanks to Richard Baldwin for all the testing
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and feedback with debugging bus lockups!
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Rev 4.0 - January 14th, 2012
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- Updated to make compatible with 8MHz clock frequency
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Rev 3.0 - January 9th, 2012
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- Modified library to be compatible with Arduino 1.0
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- Changed argument type from boolean to uint8_t in pullUp(),
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setSpeed() and receiveByte() functions for 1.0 compatability
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- Modified return values for timeout feature to report
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back where in the transmission the timeout occured.
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- added function scan() to perform a bus scan to find devices
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attached to the I2C bus. Similar to work done by Todbot
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and Nick Gammon
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Rev 2.0 - September 19th, 2011
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- Added support for timeout function to prevent
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and recover from bus lockup (thanks to PaulS
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and CrossRoads on the Arduino forum)
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- Changed return type for stop() from void to
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uint8_t to handle timeOut function
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Rev 1.0 - August 8th, 2011
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This is a modified version of the Arduino Wire/TWI
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library. Functions were rewritten to provide more functionality
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and also the use of Repeated Start. Some I2C devices will not
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function correctly without the use of a Repeated Start. The
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initial version of this library only supports the Master.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#if(ARDUINO >= 100)
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#include <Arduino.h>
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#else
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#include <WProgram.h>
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#endif
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#include <inttypes.h>
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#ifndef I2C_h
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#define I2C_h
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#define START 0x08
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#define REPEATED_START 0x10
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#define MT_SLA_ACK 0x18
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#define MT_SLA_NACK 0x20
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#define MT_DATA_ACK 0x28
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#define MT_DATA_NACK 0x30
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#define MR_SLA_ACK 0x40
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#define MR_SLA_NACK 0x48
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#define MR_DATA_ACK 0x50
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#define MR_DATA_NACK 0x58
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#define LOST_ARBTRTN 0x38
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#define TWI_STATUS (TWSR & 0xF8)
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#define SLA_W(address) (address << 1)
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#define SLA_R(address) ((address << 1) + 0x01)
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#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
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#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
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#define MAX_BUFFER_SIZE 32
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class I2C
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{
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public:
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I2C();
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void begin();
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void end();
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void timeOut(uint16_t);
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void setSpeed(uint8_t);
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void pullup(uint8_t);
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void scan();
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uint8_t available();
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uint8_t receive();
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uint8_t write(uint8_t, uint8_t);
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uint8_t write(int, int);
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uint8_t write(uint8_t, uint8_t, uint8_t);
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uint8_t write(int, int, int);
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uint8_t write(uint8_t, uint8_t, char*);
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uint8_t write(uint8_t, uint8_t, uint8_t*, uint8_t);
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uint8_t read(uint8_t, uint8_t);
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uint8_t read(int, int);
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uint8_t read(uint8_t, uint8_t, uint8_t);
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uint8_t read(int, int, int);
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uint8_t read(uint8_t, uint8_t, uint8_t*);
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uint8_t read(uint8_t, uint8_t, uint8_t, uint8_t*);
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private:
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uint8_t start();
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uint8_t sendAddress(uint8_t);
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uint8_t sendByte(uint8_t);
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uint8_t receiveByte(uint8_t);
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uint8_t stop();
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void lockUp();
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uint8_t returnStatus;
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uint8_t nack;
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uint8_t data[MAX_BUFFER_SIZE];
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static uint8_t bytesAvailable;
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static uint8_t bufferIndex;
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static uint8_t totalBytes;
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static uint16_t timeOutDelay;
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};
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extern I2C I2c;
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#endif
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