Subversion Repositories FlightCtrl

#include <avr/io.h>

#include <avr/interrupt.h>

#include <util/twi.h>

#include <util/delay.h>

#include <stdio.h>

#include "twimaster.h"

//#include "configuration.h"

//#include "controlMixer.h"

#include "analog.h"

volatile uint8_t twi_state;

volatile uint8_t dac_channel;

volatile uint8_t writeIndex;

volatile uint8_t readIndex;

volatile uint16_t I2CTimeout = 100;

uint8_t missingMotor;

MLBLC_t mkblcs[MAX_I2CCHANNELS];

uint8_t DACChannel;

#define SCL_CLOCK  200000L

#define I2C_TIMEOUT 30000

/**************************************************

 * Initialize I2C (TWI)                        

 **************************************************/

void I2C_init(void) {

        uint8_t i;

        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 = ((F_CPU / SCL_CLOCK) - 16) / 2;

        twi_state = TWI_STATE_MOTOR_TX;

        writeIndex = 0;

        readIndex = 0;

        for (i = 0; i < MAX_I2CCHANNELS; i++) {

          mkblcs[i].present = 0;

          mkblcs[i].maxPWM = 0;

        }

        SREG = sreg;

}

/****************************************

 * Start I2C                          

 ****************************************/

void I2C_start(uint8_t start_state) {

        twi_state = start_state;

        // 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 (TWEN = 1)

        // enable TWI Interrupt (TWIE = 1)

        TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN) | (1 << TWIE);

}

/****************************************

 * Stop I2C                          

 ****************************************/

void I2C_stop(uint8_t start_state) {

        twi_state = start_state;

        // 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 (TWEN = 1)

        // disable TWI Interrupt (TWIE = 0)

        TWCR = (1 << TWINT) | (1 << TWSTO) | (1 << TWEN);

}

/****************************************

 *    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);

}

/****************************************

 * Reset I2C                        

 ****************************************/

void I2C_reset(void) {

        // stop i2c bus

        I2C_stop(TWI_STATE_MOTOR_TX);

        twi_state = 0;

        writeIndex = TWDR;

        writeIndex = 0;

        readIndex = 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(TWI_STATE_MOTOR_TX);

}

/****************************************

 * I2C ISR

 ****************************************/

ISR (TWI_vect)

{

        static uint8_t missing_motor = 0;

        switch (twi_state++) { // First i2c_start from SendMotorData()

        // Master Transmit

        case 0: // TWI_STATE_MOTOR_TX

                // skip motor if not used in mixer

                while ((outputMixer[writeIndex].outputType != OUTPUT_TYPE_MOTOR) && (writeIndex < MAX_I2CCHANNELS))

                        writeIndex++;

                if (writeIndex >= MAX_I2CCHANNELS) { // writing finished, read now

                        writeIndex = 0;

                        twi_state = TWI_STATE_MOTOR_RX;

                        I2C_writeByte(0x53 + (readIndex * 2)); // select slave adress in rx mode

                } else

                        I2C_writeByte(0x52 + (writeIndex * 2)); // select slave adress in tx mode

                break;

        case 1: // Send Data to Slave

                //I2C_writeByte(outputs[writeIndex]>>LOG_CONTROL_OUTPUT_SCALING); // transmit throttle value.

            I2C_writeByte(mkblcs[writeIndex].throttle); // transmit throttle value.

                break;

        case 2: // repeat case 0+1 for all motors

                if (TWSR == TW_MT_DATA_NACK) { // Data transmitted, NACK received

                        if (!missing_motor)

                                missing_motor = writeIndex + 1;

                        if (++mkblcs[writeIndex].error == 0)

                          mkblcs[writeIndex].error = 255; // increment error counter and handle overflow

                }

                I2C_stop(TWI_STATE_MOTOR_TX);

                I2CTimeout = 10;

                writeIndex++; // next motor

                I2C_start(TWI_STATE_MOTOR_TX); // Repeated start -> switch slave or switch Master Transmit -> Master Receive

                break;

                // Master Receive Data

        case 3:

                if (TWSR != TW_MR_SLA_ACK) { //  SLA+R transmitted, if not ACK received

                        // no response from the addressed slave received

                  mkblcs[readIndex].present = 0;

                        readIndex++; // next motor

                        if (readIndex >= MAX_I2CCHANNELS)

                                readIndex = 0; // restart reading of first motor if we have reached the last one

                        I2C_stop(TWI_STATE_MOTOR_TX);

                } else {

                  mkblcs[readIndex].present = ('1' - '-') + readIndex;

                        I2C_receiveByte(); //Transmit 1st byte

                }

                missingMotor = missing_motor;

                missing_motor = 0;

                break;

        case 4: //Read 1st byte and transmit 2nd Byte

          mkblcs[readIndex].current = TWDR;

                I2C_receiveLastByte(); // nack

                break;

        case 5:

                //Read 2nd byte

          mkblcs[readIndex].maxPWM = TWDR;

                readIndex++; // next motor

                if (readIndex >= MAX_I2CCHANNELS)

                        readIndex = 0; // restart reading of first motor if we have reached the last one

                I2C_stop(TWI_STATE_MOTOR_TX);

                break;

                // Writing ADC values.

        case 7:

                I2C_writeByte(0x98); // Address the DAC

                break;

        case 8:

                I2C_writeByte(0x10 + (DACChannel << 1)); // Select DAC Channel (0x10 = A, 0x12 = B, 0x14 = C)

                break;

        case 9:

                I2C_writeByte(gyroAmplifierOffset.offsets[DACChannel]);

                break;

        case 10:

                I2C_writeByte(0x80); // 2nd byte for all channels is 0x80

                break;

        case 11:

                I2C_stop(TWI_STATE_MOTOR_TX);

                I2CTimeout = 10;

                // repeat case 7...10 until all DAC Channels are updated

                if (DACChannel < 2) {

                        DACChannel++; // jump to next channel

                        I2C_start(TWI_STATE_GYRO_OFFSET_TX); // start transmission for next channel

                } else {

                        DACChannel = 0; // reset dac channel counter

                }

                break;

        default:

                I2C_stop(TWI_STATE_MOTOR_TX);

                I2CTimeout = 10;

                writeIndex = 0;

                readIndex = 0;

        }

}

extern void twi_diagnostics(void) {

        // Check connected BL-Ctrls

        uint8_t i;

        printf("\n\rFound BL-Ctrl: ");

        for (i=0; i<MAX_I2CCHANNELS; i++) {

                mkblcs[i].throttle = 0;

        }

        I2C_start(TWI_STATE_MOTOR_TX);

        _delay_ms(2);

        readIndex = 0; // read the first I2C-Data

        for (i = 0; i < MAX_I2CCHANNELS; i++) {

                I2C_start(TWI_STATE_MOTOR_TX);

                _delay_ms(2);

                if (mkblcs[i].present)

                        printf("%d ",i+1);

        }

        for (i = 0; i < MAX_I2CCHANNELS; i++) {

                if (!mkblcs[i].present && outputMixer[i].outputType == OUTPUT_TYPE_MOTOR)

                        printf("\n\r\n\r!! MISSING BL-CTRL: %d !!",i + 1);

                mkblcs[i].error = 0;

        }

}