mirror of https://github.com/ArduPilot/ardupilot
567 lines
13 KiB
C++
567 lines
13 KiB
C++
/*
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I2C.cpp - I2C library
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Copyright (c) 2011 Wayne Truchsess. All right reserved.
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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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#include <inttypes.h>
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#include "I2C.h"
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#if defined(ARDUINO) && 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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uint8_t I2C::bytesAvailable = 0;
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uint8_t I2C::bufferIndex = 0;
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uint8_t I2C::totalBytes = 0;
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uint16_t I2C::timeOutDelay = 0;
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I2C::I2C()
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{
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}
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////////////// Public Methods ////////////////////////////////////////
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void I2C::begin()
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{
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#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
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// activate internal pull-ups for twi
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// as per note from atmega8 manual pg167
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sbi(PORTC, 4);
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sbi(PORTC, 5);
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#else
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// activate internal pull-ups for twi
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// as per note from atmega128 manual pg204
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sbi(PORTD, 0);
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sbi(PORTD, 1);
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#endif
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// initialize twi prescaler and bit rate
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cbi(TWSR, TWPS0);
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cbi(TWSR, TWPS1);
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TWBR = ((CPU_FREQ / 100000) - 16) / 2;
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// enable twi module, acks, and twi interrupt
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TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA);
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}
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void I2C::end()
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{
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TWCR = 0;
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}
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void I2C::timeOut(uint16_t _timeOut)
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{
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timeOutDelay = _timeOut;
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}
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void I2C::setSpeed(boolean _fast)
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{
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if(!_fast)
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{
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TWBR = ((CPU_FREQ / 100000) - 16) / 2;
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}
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else
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{
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TWBR = ((CPU_FREQ / 400000) - 16) / 2;
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}
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}
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void I2C::pullup(boolean activate)
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{
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if(activate)
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{
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#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
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// activate internal pull-ups for twi
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// as per note from atmega8 manual pg167
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sbi(PORTC, 4);
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sbi(PORTC, 5);
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#else
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// activate internal pull-ups for twi
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// as per note from atmega128 manual pg204
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sbi(PORTD, 0);
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sbi(PORTD, 1);
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#endif
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}
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else
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{
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#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
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// deactivate internal pull-ups for twi
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// as per note from atmega8 manual pg167
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cbi(PORTC, 4);
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cbi(PORTC, 5);
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#else
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// deactivate internal pull-ups for twi
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// as per note from atmega128 manual pg204
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cbi(PORTD, 0);
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cbi(PORTD, 1);
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#endif
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}
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}
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/////////////carry over from Wire library ///////////
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uint8_t I2C::beginTransmission(uint8_t address)
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{
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returnStatusWire = 0;
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returnStatus = 0;
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returnStatus = start();
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returnStatusWire = returnStatus;
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_W(address));
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returnStatusWire = returnStatus;
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return(returnStatus);
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}
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uint8_t I2C::beginTransmission(int address)
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{
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return(beginTransmission((uint8_t) address));
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}
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uint8_t I2C::send(uint8_t databyte)
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{
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if(returnStatusWire)
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{
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return(returnStatusWire);
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}
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returnStatus = 0;
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returnStatus = sendByte(databyte);
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returnStatusWire = returnStatus;
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return(returnStatus);
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}
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uint8_t I2C::send(int databyte)
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{
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return(send((uint8_t) databyte));
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}
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uint8_t I2C::endTransmission()
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{
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stop();
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return(returnStatusWire);
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}
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uint8_t I2C::requestFrom(int address, int numberBytes)
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{
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return(requestFrom((uint8_t) address, (uint8_t) numberBytes));
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}
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uint8_t I2C::requestFrom(uint8_t address, uint8_t numberBytes)
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{
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returnStatus = 0;
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returnStatus = read(address,numberBytes);
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if(!returnStatus)
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{
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return(numberBytes);
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}
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return(0);
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}
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uint8_t I2C::available()
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{
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return(bytesAvailable);
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}
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uint8_t I2C::receive()
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{
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bufferIndex = totalBytes - bytesAvailable;
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if(!bytesAvailable)
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{
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bufferIndex = 0;
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return(0);
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}
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bytesAvailable--;
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return(data[bufferIndex]);
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}
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/////////////////////////////////////////////////////
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uint8_t I2C::write(uint8_t address, uint8_t registerAddress)
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{
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returnStatus = 0;
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_W(address));
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if(returnStatus){return(returnStatus);}
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returnStatus = sendByte(registerAddress);
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if(returnStatus){return(returnStatus);}
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returnStatus = stop();
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return(returnStatus);
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}
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uint8_t I2C::write(int address, int registerAddress)
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{
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return(write((uint8_t) address, (uint8_t) registerAddress));
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}
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uint8_t I2C::write(uint8_t address, uint8_t registerAddress, uint8_t databyte)
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{
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returnStatus = 0;
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_W(address));
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if(returnStatus){return(returnStatus);}
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returnStatus = sendByte(registerAddress);
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if(returnStatus){return(returnStatus);}
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returnStatus = sendByte(databyte);
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if(returnStatus){return(returnStatus);}
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returnStatus = stop();
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return(returnStatus);
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}
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uint8_t I2C::write(int address, int registerAddress, int databyte)
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{
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return(write((uint8_t) address, (uint8_t) registerAddress, (uint8_t) databyte));
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}
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uint8_t I2C::write(uint8_t address, uint8_t registerAddress, char *databytes)
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{
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uint8_t bufferLength = strlen(databytes);
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returnStatus = 0;
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returnStatus = write(address, registerAddress, (uint8_t*)databytes, bufferLength);
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return(returnStatus);
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}
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uint8_t I2C::write(uint8_t address, uint8_t registerAddress, uint8_t *databytes, uint8_t numberBytes)
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{
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returnStatus = 0;
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_W(address));
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if(returnStatus){return(returnStatus);}
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returnStatus = sendByte(registerAddress);
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if(returnStatus){return(returnStatus);}
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for (uint8_t i = 0; i < numberBytes; i++)
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{
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returnStatus = sendByte(databytes[i]);
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if(returnStatus){return(returnStatus);}
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}
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returnStatus = stop();
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return(returnStatus);
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}
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uint8_t I2C::read(int address, int numberBytes)
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{
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return(read((uint8_t) address, (uint8_t) numberBytes));
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}
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uint8_t I2C::read(uint8_t address, uint8_t numberBytes)
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{
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bytesAvailable = 0;
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bufferIndex = 0;
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if(numberBytes == 0){numberBytes++;}
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nack = numberBytes - 1;
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returnStatus = 0;
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_R(address));
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if(returnStatus){return(returnStatus);}
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for(uint8_t i = 0; i < numberBytes; i++)
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{
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if( i == nack )
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{
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returnStatus = receiveByte(0);
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if(returnStatus != MR_DATA_NACK){return(returnStatus);}
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}
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else
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{
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returnStatus = receiveByte(1);
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if(returnStatus != MR_DATA_ACK){return(returnStatus);}
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}
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data[i] = TWDR;
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bytesAvailable = i+1;
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totalBytes = i+1;
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}
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returnStatus = stop();
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return(returnStatus);
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}
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uint8_t I2C::read(int address, int registerAddress, int numberBytes)
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{
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return(read((uint8_t) address, (uint8_t) registerAddress, (uint8_t) numberBytes));
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}
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uint8_t I2C::read(uint8_t address, uint8_t registerAddress, uint8_t numberBytes)
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{
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bytesAvailable = 0;
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bufferIndex = 0;
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if(numberBytes == 0){numberBytes++;}
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nack = numberBytes - 1;
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returnStatus = 0;
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_W(address));
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if(returnStatus){return(returnStatus);}
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returnStatus = sendByte(registerAddress);
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if(returnStatus){return(returnStatus);}
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_R(address));
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if(returnStatus){return(returnStatus);}
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for(uint8_t i = 0; i < numberBytes; i++)
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{
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if( i == nack )
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{
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returnStatus = receiveByte(0);
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if(returnStatus != MR_DATA_NACK){return(returnStatus);}
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}
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else
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{
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returnStatus = receiveByte(1);
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if(returnStatus != MR_DATA_ACK){return(returnStatus);}
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}
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data[i] = TWDR;
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bytesAvailable = i+1;
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totalBytes = i+1;
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}
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returnStatus = stop();
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return(returnStatus);
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}
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uint8_t I2C::read(uint8_t address, uint8_t numberBytes, uint8_t *dataBuffer)
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{
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bytesAvailable = 0;
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bufferIndex = 0;
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if(numberBytes == 0){numberBytes++;}
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nack = numberBytes - 1;
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returnStatus = 0;
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_R(address));
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if(returnStatus){return(returnStatus);}
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for(uint8_t i = 0; i < numberBytes; i++)
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{
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if( i == nack )
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{
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returnStatus = receiveByte(0);
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if(returnStatus != MR_DATA_NACK){return(returnStatus);}
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}
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else
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{
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returnStatus = receiveByte(1);
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if(returnStatus != MR_DATA_ACK){return(returnStatus);}
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}
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dataBuffer[i] = TWDR;
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bytesAvailable = i+1;
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totalBytes = i+1;
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}
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returnStatus = stop();
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return(returnStatus);
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}
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uint8_t I2C::read(uint8_t address, uint8_t registerAddress, uint8_t numberBytes, uint8_t *dataBuffer)
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{
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bytesAvailable = 0;
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bufferIndex = 0;
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if(numberBytes == 0){numberBytes++;}
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nack = numberBytes - 1;
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returnStatus = 0;
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_W(address));
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if(returnStatus){return(returnStatus);}
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returnStatus = sendByte(registerAddress);
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if(returnStatus){return(returnStatus);}
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returnStatus = start();
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if(returnStatus){return(returnStatus);}
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returnStatus = sendAddress(SLA_R(address));
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if(returnStatus){return(returnStatus);}
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for(uint8_t i = 0; i < numberBytes; i++)
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{
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if( i == nack )
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{
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returnStatus = receiveByte(0);
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if(returnStatus != MR_DATA_NACK){return(returnStatus);}
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}
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else
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{
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returnStatus = receiveByte(1);
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if(returnStatus != MR_DATA_ACK){return(returnStatus);}
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}
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dataBuffer[i] = TWDR;
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bytesAvailable = i+1;
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totalBytes = i+1;
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}
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returnStatus = stop();
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return(returnStatus);
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}
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/////////////// Private Methods ////////////////////////////////////////
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uint8_t I2C::start()
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{
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unsigned long startingTime = millis();
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TWCR = (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);
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while (!(TWCR & (1<<TWINT)))
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{
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if(!timeOutDelay){continue;}
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if((millis() - startingTime) >= timeOutDelay)
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{
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lockUp();
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return(1);
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}
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}
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if ((TWI_STATUS == START) || (TWI_STATUS == REPEATED_START))
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{
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return(0);
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}
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return(TWI_STATUS);
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}
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uint8_t I2C::sendAddress(uint8_t i2cAddress)
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{
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TWDR = i2cAddress;
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unsigned long startingTime = millis();
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TWCR = (1<<TWINT) | (1<<TWEN);
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while (!(TWCR & (1<<TWINT)))
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{
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if(!timeOutDelay){continue;}
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if((millis() - startingTime) >= timeOutDelay)
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{
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lockUp();
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return(1);
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}
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}
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if ((TWI_STATUS == MT_SLA_ACK) || (TWI_STATUS == MR_SLA_ACK))
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{
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return(0);
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}
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return(TWI_STATUS);
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}
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uint8_t I2C::sendByte(uint8_t i2cData)
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{
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TWDR = i2cData;
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unsigned long startingTime = millis();
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TWCR = (1<<TWINT) | (1<<TWEN);
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while (!(TWCR & (1<<TWINT)))
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{
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if(!timeOutDelay){continue;}
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if((millis() - startingTime) >= timeOutDelay)
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{
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lockUp();
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return(1);
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}
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}
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if (TWI_STATUS == MT_DATA_ACK)
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{
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return(0);
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}
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return(TWI_STATUS);
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}
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uint8_t I2C::receiveByte(boolean ack)
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{
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unsigned long startingTime = millis();
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if(ack)
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{
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TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA);
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}
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else
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{
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TWCR = (1<<TWINT) | (1<<TWEN);
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}
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while (!(TWCR & (1<<TWINT)))
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{
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if(!timeOutDelay){continue;}
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if((millis() - startingTime) >= timeOutDelay)
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{
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lockUp();
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return(1);
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}
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}
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return(TWI_STATUS);
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}
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uint8_t I2C::stop()
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{
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unsigned long startingTime = millis();
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TWCR = (1<<TWINT)|(1<<TWEN)| (1<<TWSTO);
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while ((TWCR & (1<<TWSTO)))
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{
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if(!timeOutDelay){continue;}
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if((millis() - startingTime) >= timeOutDelay)
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{
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lockUp();
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return(1);
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}
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}
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return(0);
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}
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void I2C::lockUp()
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{
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TWCR = 0; //releases SDA and SCL lines to high impedance
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TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA); //reinitialize TWI
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_lockup_count++;
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}
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uint8_t I2C::lockup_count(void)
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{
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return _lockup_count;
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}
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SIGNAL(TWI_vect)
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{
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switch(TWI_STATUS){
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case 0x20:
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case 0x30:
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case 0x48:
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TWCR = (1<<TWINT)|(1<<TWEN)| (1<<TWSTO); // send a stop
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break;
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case 0x38:
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case 0x68:
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case 0x78:
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case 0xB0:
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TWCR = 0; //releases SDA and SCL lines to high impedance
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TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA); //reinitialize TWI
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break;
|
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}
|
|
}
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|
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|
I2C I2c = I2C();
|