twimaster.c

此程序是无传感器无刷电机控制程序（mege8）

/*############################################################################
############################################################################*/

#include "main.h"

volatile unsigned char twi_state = 0;
unsigned char motor = 0;
unsigned char motorread = 0,MissingMotor = 0;
unsigned char motor_rx[16],motor_rx2[16];
unsigned char MotorPresent[MAX_MOTORS];
unsigned char MotorError[MAX_MOTORS];

//############################################################################
//Initzialisieren der I2C (TWI) Schnittstelle
void i2c_init(void)
//############################################################################
{
  TWSR = 0;
  TWBR = ((SYSCLK/SCL_CLOCK)-16)/2; 
}

//############################################################################
//Start I2C
void i2c_start(void) 
//############################################################################
{
    TWCR = (1<<TWSTA) | (1<<TWEN) | (1<<TWINT) | (1<<TWIE);
}

//############################################################################
void i2c_stop(void)
//############################################################################
{
    TWCR = (1<<TWEN) | (1<<TWSTO) | (1<<TWINT);
}

void i2c_reset(void)
//############################################################################
{
                 i2c_stop();                
                 twi_state = 0;
                 motor = TWDR;
                 motor = 0;
                 TWCR = 0x80;
                 TWAMR = 0;
                 TWAR = 0;
                 TWDR = 0;
                 TWSR = 0;
                 TWBR = 0;
                 i2c_init();
                 i2c_start();
                 i2c_write_byte(0);
}

//############################################################################
void i2c_write_byte(char byte)
//############################################################################
{ 
    TWSR = 0x00;
    TWDR = byte;
    TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE);
}

/****************************************/
/*    Write to I2C                      */
/****************************************/
void I2C_WriteByte(int8_t byte)
{
    // move byte to send into TWI Data Register
    TWDR = byte;
    // clear interrupt flag (TWINT = 1)
    // enable i2c bus (TWEN = 1)
    // enable interrupt (TWIE = 1)
    TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE);
}

/****************************************/
/*    Receive byte and send ACK         */
/****************************************/
void I2C_ReceiveByte(void)
{
   TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE) | (1<<TWEA);
}

/****************************************/
/* I2C receive last byte and send no ACK*/
/****************************************/
void I2C_ReceiveLastByte(void)
{
   TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE);
}



//############################################################################
SIGNAL (TWI_vect)
//############################################################################
{
 static unsigned char missing_motor;
     switch(twi_state++)
        {
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// Writing the Data
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        case 0:
                        while(Mixer.Motor[motor][0] <= 0 && motor < MAX_MOTORS) motor++;  // skip if not used
                                if(motor == MAX_MOTORS)  // writing finished -> now read 
                                { 
                                 motor = 0; 
                                 twi_state = 3; 
                                 i2c_write_byte(0x53+(motorread*2));
                                 } 
                                else i2c_write_byte(0x52+(motor*2));
                break;
        case 1:
                i2c_write_byte(Motor[motor++]);
                break;
        case 2:
                if(TWSR == 0x30) { if(!missing_motor) missing_motor = motor; if(++MotorError[motor-1] == 0) MotorError[motor-1] = 255;}
                i2c_stop();
                I2CTimeout = 10;
                twi_state = 0;
                i2c_start();   
                break; 
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// Reading Data
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        case 3:
               //Transmit 1st byte for reading
                if(TWSR != 0x40)  // Error?
                 { 
                  MotorPresent[motorread] = 0;
                  motorread++; 
                  if(motorread >= MAX_MOTORS) motorread = 0;
                  i2c_stop();
                  twi_state = 0;
                 }
                 else 
                 {
                  MotorPresent[motorread] = ('1' - '-') + motorread;
                  I2C_ReceiveByte();
                 }
                MissingMotor = missing_motor;
                missing_motor = 0;
                break;
        case 4: //Read 1st byte and transmit 2nd Byte
                motor_rx[motorread] = TWDR;
                I2C_ReceiveLastByte(); //nack
                break;
        case 5:
                //Read 2nd byte
                motor_rx2[motorread++] = TWDR;
                if(motorread >= MAX_MOTORS) motorread = 0;
                i2c_stop();
                twi_state = 0;
                break;
                        
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// writing Gyro-Offset
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
        case 8: 
                i2c_write_byte(0x98); // Address of the DAC
                break;
        case 9: 
                i2c_write_byte(0x10); // Update Channel A
                break;
        case 10: 
                i2c_write_byte(AnalogOffsetNick); // Value
                break;
        case 11: 
                i2c_write_byte(0x80); // Value
                break;
        case 12: 
                i2c_stop();               
                I2CTimeout = 10;
                i2c_start();   
                break;
        case 13: 
                i2c_write_byte(0x98); // Address of the DAC
                break;
        case 14: 
                i2c_write_byte(0x12); // Update Channel B
                break;
        case 15: 
                i2c_write_byte(AnalogOffsetRoll); // Value
                break;
        case 16: 
                i2c_write_byte(0x80); // Value
                break;
        case 17: 
                i2c_stop();               
                I2CTimeout = 10;
                i2c_start();   
                break;
        case 18: 
                i2c_write_byte(0x98); // Address of the DAC
                break;
        case 19: 
                i2c_write_byte(0x14); // Update Channel C
                break;
        case 20: 
                i2c_write_byte(AnalogOffsetGier); // Value
                break;
        case 21: 
                i2c_write_byte(0x80); // Value
                break;
        case 22: 
                i2c_stop();               
                I2CTimeout = 10;
                twi_state = 0;
                break;
        default: twi_state = 0;
                break;        
                }
 TWCR |= 0x80;
}