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;
        }
}