Subversion Repositories FlightCtrl

/*

Copyright 2007, Niklas Nold

This program (files compass.c and compass.h) is free software; you can redistribute it and/or modify

it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation;

either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;

without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License

along with this program. If not, see <http://www.gnu.org/licenses/>.

Please note: All the other files for the project "Mikrokopter" by H. Buss are under the license (license_buss.txt) published by www.mikrokopter.de

*/

#include "main.h"

MM3_struct MM3;

//############################################################################

//Initialisierung der SPI-Schnittstelle

void init_spi(void)

//############################################################################

{

        SPCR = (1<<SPIE)|(1<<SPE)|(1<<MSTR)|(1<<SPR1)|(1<<SPR0);        //Interrupt an, Master, 156 kHz Oszillator

        //SPSR = (1<<SPI2X);

    DDRB |= (1<<PB7)|(1<<PB5)|(1<<PB2); // J8, MOSI, SCK Ausgang

        PORTD &= ~(1<<PD3);     // J5 auf Low

        MM3.AXIS = MM3_X;

        MM3.STATE = MM3_RESET;

}

//############################################################################

//Wird in der SIGNAL (SIG_OVERFLOW0) aufgerufen

void MM3_timer0(void)

//############################################################################

{

        switch (MM3.STATE)

        {

        case MM3_RESET:                        

                PORTB |= (1<<PB2);      // J8 auf High, MM3 Reset

                MM3.STATE = MM3_START_TRANSFER;

                break;

        case MM3_START_TRANSFER:

                PORTB &= ~(1<<PB2);     // J8 auf Low (war ~125 µs auf High)            

                if (MM3.AXIS == MM3_X) SPDR = 0x51;                     // Schreiben ins SPDR löst automatisch Übertragung (MOSI und MISO) aus

                else if (MM3.AXIS == MM3_Y) SPDR = 0x52;                // Micromag Period Select ist auf 1024 (0x50)

                else if (MM3.AXIS == MM3_Z) SPDR = 0x53;                // 1: x-Achse, 2: Y-Achse, 3: Z-Achse

                MM3.DRDY = SetDelay(15);                // Laut Datenblatt max. Zeit bis Messung fertig (bei PS 1024)

                MM3.STATE = MM3_WAIT_DRDY;

                break;

        case MM3_WAIT_DRDY:

                if (CheckDelay(MM3.DRDY)) {SPDR = 0x00;MM3.STATE = MM3_DRDY;} // Irgendwas ins SPDR, damit Übertragung ausgelöst wird, wenn Wartezeit vorbei

                break;

        case MM3_IDLE:         

                break;

        }

}

//############################################################################

//SPI byte ready

SIGNAL (SIG_SPI)

//############################################################################

{      

        switch (MM3.STATE)

        {      

        case MM3_DRDY:

                        // 1. Byte ist da, abspeichern, an die MSB-Stelle rücken und Übertragung von 2. Byte auslösen

                if (MM3.AXIS == MM3_X) {MM3.x_axis=SPDR; MM3.x_axis<<=8; SPDR=0x00; MM3.STATE=MM3_X_BYTE2; break;}

                if (MM3.AXIS == MM3_Y) {MM3.y_axis=SPDR; MM3.y_axis<<=8; SPDR=0x00; MM3.STATE=MM3_Y_BYTE2; break;}

                if (MM3.AXIS == MM3_Z) {MM3.z_axis=SPDR; MM3.z_axis<<=8; SPDR=0x00; MM3.STATE=MM3_Z_BYTE2; break;}

        case MM3_X_BYTE2:       // 2. Byte der entsprechenden Achse ist da.             

                MM3.x_axis |= SPDR;

                MM3.x_axis -= OFF_X;    // Sofort Offset aus der Kalibrierung berücksichtigen

                MM3.AXIS = MM3_Y;

                MM3.STATE = MM3_RESET;

                break;

        case MM3_Y_BYTE2:

                MM3.y_axis |= SPDR;            

                MM3.y_axis -= OFF_Y;

                MM3.AXIS = MM3_Z;

                MM3.STATE = MM3_RESET;

                break;

        case MM3_Z_BYTE2:

                MM3.z_axis |= SPDR;

                MM3.z_axis -= OFF_Z;

                MM3.AXIS = MM3_X;

                MM3.STATE = MM3_RESET;         

                // Zeitnahe Speicherung der aktuellen Nick-/Rollneigung in °

                MM3.NickGrad = IntegralNick/(EE_Parameter.UserParam1*8);

                MM3.RollGrad = IntegralRoll/(EE_Parameter.UserParam2*8);

                break; 

        }

}

signed int MM3_heading(void)

{

        float sin_nick, cos_nick, sin_roll, cos_roll;

        signed int x_corr, y_corr;

        signed int heading;

        // Berechung von sinus und cosinus

        sin_nick = sin_f(MM3.NickGrad);

        cos_nick = cos_f(MM3.NickGrad);

        sin_roll = sin_f(MM3.RollGrad);

        cos_roll = cos_f(MM3.RollGrad);      

    // Neigungskompensation

        x_corr = (cos_nick * MM3.x_axis) + (((sin_roll *  MM3.y_axis) - (cos_roll * MM3.z_axis)) * sin_nick);

        y_corr = ((cos_roll * MM3.y_axis) + (sin_roll * MM3.z_axis));

        // Winkelberechnung

        heading = arctan_i(x_corr, y_corr);

return (heading);

}