Code:
/*! \file i2c.c \brief I2C interface using AVR Two-Wire Interface (TWI) hardware. */
//*****************************************************************************
//
// File Name : 'i2c.c'
// Title : I2C interface using AVR Two-Wire Interface (TWI) hardware
// Author : Pascal Stang - Copyright (C) 2002-2003
// Created : 2002.06.25
// Revised : 2003.03.02
// Version : 0.9
// Target MCU : Atmel AVR series
// Editor Tabs : 4
//
// Description : I2C (pronounced "eye-squared-see") is a two-wire bidirectional
// network designed for easy transfer of information between a wide variety
// of intelligent devices. Many of the Atmel AVR series processors have
// hardware support for transmitting and receiving using an I2C-type bus.
// In addition to the AVRs, there are thousands of other parts made by
// manufacturers like Philips, Maxim, National, TI, etc that use I2C as
// their primary means of communication and control. Common device types
// are A/D & D/A converters, temp sensors, intelligent battery monitors,
// MP3 decoder chips, EEPROM chips, multiplexing switches, etc.
//
// I2C uses only two wires (SDA and SCL) to communicate bidirectionally
// between devices. I2C is a multidrop network, meaning that you can have
// several devices on a single bus. Because I2C uses a 7-bit number to
// identify which device it wants to talk to, you cannot have more than
// 127 devices on a single bus.
//
// I2C ordinarily requires two 4.7K pull-up resistors to power (one each on
// SDA and SCL), but for small numbers of devices (maybe 1-4), it is enough
// to activate the internal pull-up resistors in the AVR processor. To do
// this, set the port pins, which correspond to the I2C pins SDA/SCL, high.
// For example, on the mega163, sbi(PORTC, 0); sbi(PORTC, 1);.
//
// For complete information about I2C, see the Philips Semiconductor
// website. They created I2C and have the largest family of devices that
// work with I2C.
//
// Note: Many manufacturers market I2C bus devices under a different or generic
// bus name like "Two-Wire Interface". This is because Philips still holds
// "I2C" as a trademark. For example, SMBus and SMBus devices are hardware
// compatible and closely related to I2C. They can be directly connected
// to an I2C bus along with other I2C devices are are generally accessed in
// the same way as I2C devices. SMBus is often found on modern motherboards
// for temp sensing and other low-level control tasks.
//
// This code is distributed under the GNU Public License
// which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************
#include <inttypes.h>
#include <stdbool.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/signal.h>
#include <stdlib.h>
#include <math.h>
#include <avr/io.h>
#include <avr/signal.h>
#include <avr/interrupt.h>
#include <compat/twi.h>
#include "i2c.h"
//#include "stdserial.h"
// Standard I2C bit rates are:
// 100KHz for slow speed
// 400KHz for high speed
#define I2C_DEBUG
// I2C state and address variables
static volatile eI2cStateType I2cState;
static u08 I2cDeviceAddrRW;
// send/transmit buffer (outgoing data)
static u08 I2cSendData[I2C_SEND_DATA_BUFFER_SIZE];
static u08 I2cSendDataIndex;
static u08 I2cSendDataLength;
// receive buffer (incoming data)
static u08 I2cReceiveData[I2C_RECEIVE_DATA_BUFFER_SIZE];
static u08 I2cReceiveDataIndex;
static u08 I2cReceiveDataLength;
// function pointer to I2C receive routine
//! I2cSlaveReceive is called when this processor
// is addressed as a slave for writing
static void (*i2cSlaveReceive)(u08 receiveDataLength, u08* recieveData);
//! I2cSlaveTransmit is called when this processor
// is addressed as a slave for reading
static u08 (*i2cSlaveTransmit)(u08 transmitDataLengthMax, u08* transmitData);
// functions
void i2c_Init(void)
{
// set pull-up resistors on I2C bus pins
sbi(PORTC, 0); // I2C SCL on ATmega163,323,16,32,etc
sbi(PORTC, 1); // I2C SDA on ATmega163,323,16,32,etc
//sbi(PORTD, 0); // I2C SCL on ATmega128,64
//sbi(PORTD, 1); // I2C SDA on ATmega128,64
// clear SlaveReceive and SlaveTransmit handler to null
i2cSlaveReceive = 0;
i2cSlaveTransmit = 0;
// set I2C bit rate to 100KHz
i2cSetBitrate(100);
// enable TWI (two-wire interface)
sbi(TWCR, TWEN);
// set state
I2cState = I2C_IDLE;
// enable TWI interrupt and slave address ACK
sbi(TWCR, TWIE);
sbi(TWCR, TWEA);
//outb(TWCR, (inb(TWCR)&TWCR_CMD_MASK)|BV(TWINT)|BV(TWEA));
// enable interrupts
sei();
}
es kommen anschließend noch mal die gleichen fehlerjedoch andere functions:
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