Subversion Repositories MK3Mag

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

MK3Mag 3D-Magnet sensor

!!! THIS IS NOT FREE SOFTWARE !!!

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

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Copyright (c) 05.2008 Holger Buss

// + Thanks to Ilja Fähnrich (P_Latzhalter)

// + Nur für den privaten Gebrauch

// + www.MikroKopter.com

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Die Portierung der Software (oder Teile davon) auf andere Systeme (ausser der Hardware von www.mikrokopter.de) ist nur

// + mit unserer Zustimmung zulässig

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Es gilt für das gesamte Projekt (Hardware, Software, Binärfiles, Sourcecode und Dokumentation),

// + dass eine Nutzung (auch auszugsweise) nur für den privaten (nicht-kommerziellen) Gebrauch zulässig ist.

// + AUSNAHME: Ein bei www.mikrokopter.de erworbener vorbestückter MK3Mag darf als Baugruppe auch in kommerziellen Systemen verbaut werden

// + Im Zweifelsfall bitte anfragen bei: info@mikrokopter.de

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Werden Teile des Quellcodes (mit oder ohne Modifikation) weiterverwendet oder veröffentlicht,

// + unterliegen sie auch diesen Nutzungsbedingungen und diese Nutzungsbedingungen incl. Copyright müssen dann beiliegen

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Sollte die Software (auch auszugesweise) oder sonstige Informationen des MikroKopter-Projekts

// + auf anderen Webseiten oder sonstigen Medien veröffentlicht werden, muss unsere Webseite "http://www.mikrokopter.de"

// + eindeutig als Ursprung verlinkt werden

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Keine Gewähr auf Fehlerfreiheit, Vollständigkeit oder Funktion

// + Benutzung auf eigene Gefahr

// + Wir übernehmen keinerlei Haftung für direkte oder indirekte Personen- oder Sachschäden

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Die Funktion printf_P() unterliegt ihrer eigenen Lizenz und ist hiervon nicht betroffen

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Redistributions of source code (with or without modifications) must retain the above copyright notice,

// + this list of conditions and the following disclaimer.

// +   * PORTING this software (or parts of it) to systems (other than hardware from www.mikrokopter.de) is NOT allowed

// +   * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived

// +     from this software without specific prior written permission.

// +   * The use of this project (hardware, software, binary files, sources and documentation) is only permittet

// +     for non-commercial use (directly or indirectly)

// +     Commercial use (for excample: selling of MikroKopters, selling of PCBs, assembly, ...) is only permitted

// +     with our written permission

// +     Exception: A preassembled MK3Mag, purchased from www.mikrokopter.de may be used as a part of commercial systems

// +     In case of doubt please contact: info@MikroKopter.de

// +   * If sources or documentations are redistributet on other webpages, our webpage (http://www.MikroKopter.de) must be

// +     clearly linked as origin

// +  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

// +  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

// +  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

// +  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

// +  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

// +  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

// +  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

// +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

// +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

// +  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

// +  POSSIBILITY OF SUCH DAMAGE.

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

#include <avr/io.h>

#include <avr/interrupt.h>

#include <util/twi.h>

#include "twislave.h"

#include "uart.h"

#include "main.h"

#include "timer0.h"

#define TWI_BUS_ERR_1   0x00

#define TWI_BUS_ERR_2   0xF8

// Status Slave RX Mode

#define SR_SLA_ACK      0x60

#define SR_LOST_ACK     0x68

#define SR_GEN_CALL_ACK 0x70

#define GEN_LOST_ACK    0x78

#define SR_PREV_ACK     0x80

#define SR_PREV_NACK    0x88

#define GEN_PREV_ACK    0x90

#define GEN_PREV_NACK   0x98

#define STOP_CONDITION  0xA0

#define REPEATED_START  0xA0

// Status Slave TX mode

#define SW_SLA_ACK      0xA8

#define SW_LOST_ACK     0xB0

#define SW_DATA_ACK     0xB8

#define SW_DATA_NACK    0xC0

#define SW_LAST_ACK     0xC8

uint8_t I2C_RxBufferSize, I2C_TxBufferSize;

uint8_t *I2C_TxBuffer, *I2C_RxBuffer;

uint8_t Tx_Idx = 0, Rx_Idx = 0, I2C_Direction;

uint8_t I2C_Command;

I2C_Heading_t       I2C_Heading;

I2C_WriteAttitude_t I2C_WriteAttitude;

I2C_Mag_t           I2C_Mag;

I2C_EEPROM_t        I2C_ReadEEPROM, I2C_WriteEEPROM;

I2C_Version_t       I2C_Version;

I2C_WriteCal_t      I2C_WriteCal;

void I2C_Init(void)

{

        uint8_t sreg = SREG;

        cli();

        //SPI SCK/SCL and  MISO/SDA are at put together on the same connector pin in the schematic

        // set PB4 (SCK) and PB5 (MISO) as input pull up

        DDRB &= ~((1<<DDB4)|(1<<DDB5));

        PORTB |= ((1<<PORTB4)|(1<<PORTB5));

        // set PC4 (SDA) and PC5 (SCL) as input pull up

        DDRC &= ~((1<<DDC4)|(1<<DDC5));

        PORTC |= ((1<<PORTC4)|(1<<PORTC5));

         // set own address

    TWAR = I2C_SLAVE_ADDRESS; // set own address

        // TWI Control Register

        // clear TWI interrupt flag (TWINT=1)

        // enable TWI Acknowledge Bit (TWEA = 1)

        // disable TWI START Condition Bit (TWSTA = 0), SLAVE

        // disable TWI STOP Condition Bit (TWSTO = 0), SLAVE

        // disable TWI Write Collision Flag (TWWC = 0)

        // enable i2c (TWEN = 1)

        // enable TWI Interrupt (TWIE = 1)

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

        // update version info

        I2C_Version.Major = VERSION_MAJOR;

        I2C_Version.Minor = VERSION_MINOR;

        I2C_Version.Compatible = I2C_PROTOCOL_COMP;

        SREG = sreg;

}

#define TWCR_ACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)

ISR (TWI_vect)

{

        // check event

        switch (TWSR & 0xF8)

        {

        case SR_SLA_ACK:

            Rx_Idx = 0;

                        TWCR_ACK;

            return;

        case SR_PREV_ACK: // data byte received

                        if (Rx_Idx  == 0)

                        {

                                I2C_Command = TWDR;

                                switch(I2C_Command)

                                {

                                        case I2C_CMD_VERSION:

                                                I2C_TxBuffer = (uint8_t *)&I2C_Version;

                                                I2C_TxBufferSize = sizeof(I2C_Version);

                                                I2C_RxBufferSize = 0;

                                                break;

                                        case I2C_CMD_WRITE_EEPROM:

                                                I2C_TxBufferSize = 0;

                                                I2C_RxBuffer = (uint8_t *)&I2C_WriteEEPROM;

                                                I2C_RxBufferSize = sizeof(I2C_WriteEEPROM);

                                                break;

                                        case I2C_CMD_WRITE_CAL:

                                                I2C_TxBufferSize = 0;

                                                I2C_RxBuffer = (uint8_t *)&I2C_WriteCal;

                                                I2C_RxBufferSize = sizeof(I2C_WriteCal);

                                                break;

                                        case I2C_CMD_READ_EEPROM:

                                                I2C_TxBuffer = (uint8_t *)&I2C_ReadEEPROM.Content;

                                                I2C_TxBufferSize = 2;

                                                I2C_RxBuffer = (uint8_t *)&I2C_ReadEEPROM;

                                                I2C_RxBufferSize = 1;

                                                break;

                                        case I2C_CMD_READ_MAG:

                                                I2C_TxBuffer = (uint8_t *)&I2C_Mag;

                                                I2C_TxBufferSize = sizeof(I2C_Mag);

                                                I2C_RxBufferSize = 0;

                                                I2C_Mag.MagX = MagnetX;

                                                I2C_Mag.MagY = MagnetY;

                                                I2C_Mag.MagZ = MagnetZ;

                                                break;

                                        case I2C_CMD_READ_HEADING:

                                                I2C_TxBuffer = (uint8_t *)&I2C_Heading;

                                                I2C_TxBufferSize = sizeof(I2C_Heading);

                                                I2C_RxBuffer =  (uint8_t *)&I2C_WriteAttitude;

                                                I2C_RxBufferSize = sizeof(I2C_WriteAttitude);

                                                // update heading from global variable

                                                I2C_Heading.Heading = Heading;

                                                // copy current attitude from I2C rx buffer to uart rx buffer (this is used for the calulation of the heading)

                                                ExternData.Attitude[NICK] = I2C_WriteAttitude.Nick;

                                                ExternData.Attitude[ROLL] = I2C_WriteAttitude.Roll;

                                                break;

                                }

                        }

                        else // Rx_Idx  != 0

                        {

                                // fill receiver buffer

                                if ((Rx_Idx - 1) < I2C_RxBufferSize) I2C_RxBuffer[Rx_Idx - 1] = TWDR;

                        }

                        // next byte

                        Rx_Idx++;

            I2C_Timeout = 500;

                        TWCR_ACK; // send acknowledge

            return;

        case SW_SLA_ACK: // slave transmitter selected

                // reset position in tx buffer

            Tx_Idx = 0;

            // write first bte o tx buffer to the twi data register

                        if (I2C_TxBufferSize > 0) TWDR = I2C_TxBuffer[Tx_Idx++];

                        // send acknowledge

            TWCR_ACK;

            return;

                case SW_DATA_ACK: // send data byte

                        // put next byte from tx buffer to twi data register

            if (Tx_Idx < I2C_TxBufferSize) TWDR = I2C_TxBuffer[Tx_Idx++];

                        else TWDR = 0x00;

                        TWCR_ACK; // send acknowledge

            return;

        // clear Bus-Error

        case TWI_BUS_ERR_2:

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

        // clear Bus-Error

        case TWI_BUS_ERR_1:

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

        }

        // clear interrupt flag (TWINT = 1)

        // enable TWI Acknowledge Bit (TWEA = 1)

        // enable TWI (TWEN = 1)

        // enable TWI interrpt (TWIE = 1)

    TWCR = (1<<TWEA) | (1<<TWINT) | (1<<TWEN) | (1<<TWIE); // TWI Reset

}