| 0,0 → 1,208 |
|---|
| /*############################################################################ |
| ############################################################################*/ |
| |
| #include <avr/io.h> |
| #include <avr/interrupt.h> |
| |
| #include "main.h" |
| #include "twimaster.h" |
| #include "fc.h" |
| |
| volatile uint8_t twi_state = 0; |
| volatile uint8_t motor = 0; |
| volatile uint8_t motor_rx[MOTOR_COUNT*2]; |
| |
| /**************************************************/ |
| /* Initialize I2C (TWI) */ |
| /**************************************************/ |
| void I2C_Init(void) |
| { |
| uint8_t sreg = SREG; |
| cli(); |
| |
| // SDA is INPUT |
| DDRC &= ~(1<<DDC1); |
| // SCL is output |
| DDRC |= (1<<DDC0); |
| // pull up SDA |
| PORTC |= (1<<PORTC0)|(1<<PORTC1); |
| |
| // TWI Status Register |
| // prescaler 1 (TWPS1 = 0, TWPS0 = 0) |
| TWSR &= ~((1<<TWPS1)|(1<<TWPS0)); |
| |
| // set TWI Bit Rate Register |
| TWBR = ((SYSCLK/SCL_CLOCK)-16)/2; |
| |
| SREG = sreg; |
| } |
| |
| /****************************************/ |
| /* Start I2C */ |
| /****************************************/ |
| void I2C_Start(void) |
| { |
| // TWI Control Register |
| // clear TWI interrupt flag (TWINT=1) |
| // disable TWI Acknowledge Bit (TWEA = 0) |
| // enable TWI START Condition Bit (TWSTA = 1), MASTER |
| // disable TWI STOP Condition Bit (TWSTO = 0) |
| // disable TWI Write Collision Flag (TWWC = 0) |
| // enable i2c (TWIE = 1) |
| // enable TWI Interrupt (TWIE = 1) |
| TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN) | (1<<TWIE); |
| } |
| |
| /****************************************/ |
| /* Stop I2C */ |
| /****************************************/ |
| void I2C_Stop(void) |
| { |
| // TWI Control Register |
| // clear TWI interrupt flag (TWINT=1) |
| // disable TWI Acknowledge Bit (TWEA = 0) |
| // diable TWI START Condition Bit (TWSTA = 1), no MASTER |
| // enable TWI STOP Condition Bit (TWSTO = 1) |
| // disable TWI Write Collision Flag (TWWC = 0) |
| // enable i2c (TWIE = 1) |
| // disable TWI Interrupt (TWIE = 0) |
| TWCR = (1<<TWINT) | (1<<TWSTO) | (1<<TWEN); |
| } |
| |
| /****************************************/ |
| /* Reset I2C */ |
| /****************************************/ |
| void I2C_Reset(void) |
| { |
| // stop i2c bus |
| I2C_Stop(); |
| twi_state = 0; |
| motor = TWDR; // ?? |
| motor = 0; |
| TWCR = (1<<TWINT); // reset to original state incl. interrupt flag reset |
| TWAMR = 0; |
| TWAR = 0; |
| TWDR = 0; |
| TWSR = 0; |
| TWBR = 0; |
| I2C_Init(); |
| I2C_Start(); |
| I2C_WriteByte(0); |
| } |
| |
| /****************************************/ |
| /* 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 intterupt (TWIW = 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); |
| } |
| |
| |
| /****************************************/ |
| /* I2C ISR */ |
| /****************************************/ |
| ISR (TWI_vect) |
| |
| { |
| static uint8_t motorread = 0; |
| |
| switch (twi_state++) // First i2s_start from SendMotorData() |
| { |
| // Master Transmit |
| case 0: // Send SLA-W |
| I2C_WriteByte(0x52+(motor*2)); |
| break; |
| case 1: // Send Data to Salve |
| #ifdef HEXAKOPTER |
| switch(motor++) |
| { |
| case 0: |
| I2C_WriteByte(Motor_FrontLeft); |
| break; |
| case 1: |
| I2C_WriteByte(Motor_RearRight); |
| break; |
| case 2: |
| I2C_WriteByte(Motor_FrontRight); |
| break; |
| case 3: |
| I2C_WriteByte(Motor_RearLeft); |
| break; |
| case 4: |
| I2C_WriteByte(Motor_Right); |
| break; |
| case 5: |
| I2C_WriteByte(Motor_Left); |
| break; |
| } |
| |
| #else |
| switch(motor++) |
| { |
| case 0: |
| I2C_WriteByte(Motor_Front); |
| break; |
| case 1: |
| I2C_WriteByte(Motor_Rear); |
| break; |
| case 2: |
| I2C_WriteByte(Motor_Right); |
| break; |
| case 3: |
| I2C_WriteByte(Motor_Left); |
| break; |
| } |
| #endif |
| break; |
| case 2: // repeat case 0+1 for all Slaves |
| if (motor<MOTOR_COUNT) twi_state = 0; |
| I2C_Start(); // Repeated start -> switch salve or switch Master Transmit -> Master Receive |
| break; |
| |
| // Master Receive |
| case 3: // Send SLA-R |
| I2C_WriteByte(0x53+(motorread*2)); |
| break; |
| case 4: |
| //Transmit 1st byte |
| I2C_ReceiveByte(); |
| break; |
| case 5: //Read 1st byte and transmit 2nd Byte |
| motor_rx[motorread] = TWDR; |
| I2C_ReceiveLastByte(); |
| break; |
| case 6: |
| //Read 2nd byte |
| motor_rx[motorread+4] = TWDR; |
| if (++motorread >= MOTOR_COUNT) motorread=0; |
| |
| default: |
| I2C_Stop(); |
| twi_state = 0; |
| I2CTimeout = 10; |
| motor = 0; |
| } |
| } |