ardupilot/libraries/I2C/I2C.h

124 lines
3.5 KiB
C++

/*
I2C.h - I2C library
Copyright (c) 2011 Wayne Truchsess. All right reserved.
Rev 2.0 - September 19th, 2011
- Added support for timeout function to prevent
and recover from bus lockup (thanks to PaulS
and CrossRoads on the Arduino forum)
- Changed return type for stop() from void to
uint8_t to handle timeOut function
Rev 1.0 - August 8th, 2011
This is a modified version of the Arduino Wire/TWI
library. Functions were rewritten to provide more functionality
and also the use of Repeated Start. Some I2C devices will not
function correctly without the use of a Repeated Start. The
initial version of this library only supports the Master.
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
*/
#include <inttypes.h>
#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#ifndef I2C_h
#define I2C_h
#define START 0x08
#define REPEATED_START 0x10
#define MT_SLA_ACK 0x18
#define MT_DATA_ACK 0x28
#define MR_SLA_ACK 0x40
#define MR_DATA_ACK 0x50
#define MR_DATA_NACK 0x58
#define TWI_STATUS (TWSR & 0xF8)
#define SLA_W(address) (address << 1)
#define SLA_R(address) ((address << 1) + 0x01)
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#define MAX_BUFFER_SIZE 32
#ifndef CPU_FREQ
#define CPU_FREQ 16000000L
#endif
class I2C
{
public:
I2C();
void begin();
void end();
void timeOut(uint16_t);
void setSpeed(boolean);
void pullup(boolean);
///////carry over from Wire library////////
uint8_t returnStatusWire;
uint8_t beginTransmission(uint8_t);
uint8_t beginTransmission(int);
uint8_t send(uint8_t);
uint8_t send(int);
uint8_t endTransmission();
uint8_t requestFrom(uint8_t, uint8_t);
uint8_t requestFrom(int, int);
uint8_t available();
///////////////////////////////////////////
uint8_t write(uint8_t, uint8_t);
uint8_t write(int, int);
uint8_t write(uint8_t, uint8_t, uint8_t);
uint8_t write(int, int, int);
uint8_t write(uint8_t, uint8_t, char*);
uint8_t write(uint8_t, uint8_t, uint8_t*, uint8_t);
uint8_t read(uint8_t, uint8_t);
uint8_t read(int, int);
uint8_t read(uint8_t, uint8_t, uint8_t);
uint8_t read(int, int, int);
uint8_t read(uint8_t, uint8_t, uint8_t*);
uint8_t read(uint8_t, uint8_t, uint8_t, uint8_t*);
uint8_t receive();
uint8_t lockup_count();
private:
uint8_t start();
uint8_t sendAddress(uint8_t);
uint8_t sendByte(uint8_t);
uint8_t receiveByte(boolean);
uint8_t stop();
void lockUp();
uint8_t returnStatus;
uint8_t nack;
uint8_t data[MAX_BUFFER_SIZE];
uint8_t _lockup_count;
static uint8_t bytesAvailable;
static uint8_t bufferIndex;
static uint8_t totalBytes;
static uint16_t timeOutDelay;
};
extern I2C I2c;
#endif