WebSVN - MK3Mag - Diff - Rev 22 and 23 - /branches/MK3Mag V0.14 Code Redesign Killagreg/twislave.c

 /*#######################################################################################
 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"
 #include "led.h"
-uint8_t I2C_RxBufferSize = 0, I2C_TxBufferSize = 0;
+volatile uint8_t I2C_RxBufferSize = 0, I2C_TxBufferSize = 0;
-uint8_t *I2C_TxBuffer = 0, *I2C_RxBuffer = 0;
+volatile uint8_t *I2C_TxBuffer = 0, *I2C_RxBuffer = 0;
-uint8_t Tx_Idx = 0, Rx_Idx = 0;
+volatile uint8_t Tx_Idx = 0, Rx_Idx = 0;
-I2C_Heading_t       I2C_Heading;
+struct I2C_Heading_t       I2C_Heading;
-I2C_WriteAttitude_t I2C_WriteAttitude;
+struct I2C_WriteAttitude_t I2C_WriteAttitude;
-I2C_Mag_t           I2C_Mag;
-I2C_EEPROM_t        I2C_ReadEEPROM, I2C_WriteEEPROM;
+struct I2C_Mag_t           I2C_Mag;
-I2C_Version_t       I2C_Version;
+struct I2C_Version_t       I2C_Version;
-I2C_WriteCal_t      I2C_WriteCal;
+struct I2C_WriteCal_t      I2C_WriteCal;
 void I2C_Init(void)
+{
         uint8_t sreg;
         // backup status register
         sreg = SREG;
     // disable global interrupts
         cli();
         // 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 tristate
+        // set PB4 (SCK) and PB5 (MISO) as input pull up
         DDRB &= ~((1<<DDB4)|(1<<DDB5));
-        PORTB &= ~((1<<PORTB4)|(1<<PORTB5));
+        PORTB |= ((1<<PORTB4)|(1<<PORTB5));
         // set PC4 (SDA) and PC5 (SCL) as input tristate
         DDRC &= ~((1<<DDC4)|(1<<DDC5));
         PORTC &= ~((1<<PORTC4)|(1<<PORTC5));
         I2C_TxBuffer = 0;
         Tx_Idx = 0;
         I2C_TxBufferSize = 0;
         I2C_RxBuffer = 0;
         Rx_Idx = 0;
         I2C_RxBufferSize = 0;
         TWCR &= ~(1<<TWSTA)|(1<<TWSTO);
         TWCR|= (1<<TWEA) | (1<<TWEN)|(1<<TWIE);
         // set own address
         // set own address in the upper 7 bits
     TWAR = I2C_SLAVE_ADDRESS; // set own address only the upper 7 bits are relevant
         // TWI Control Register
         // enable TWI Acknowledge Bit (TWEA = 1)
         // disable TWI START Condition Bit (TWSTA = 0), SLAVE
         // disable TWI  STOP Condition Bit (TWSTO = 0), SLAVE
         // enable TWI (TWEN = 1)
         // enable TWI Interrupt (TWIE = 1)
-        TWCR &= ~((1<<TWSTA)|(1<<TWSTO));
-        TWCR |= (1<<TWEA)|(1<<TWEN)|(1<<TWIE);
+        TWCR |= (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(1<<TWSTO)|(0<<TWWC);
         // update version info
         I2C_Version.Major = VERSION_MAJOR;
         I2C_Version.Minor = VERSION_MINOR;
         I2C_Version.Compatible = I2C_PROTOCOL_COMP;
         // resore status register
         SREG = sreg;
+}
 // send ACK after recieving a byte / ACK is expected after transmitting a byte
-#define TWCR_ACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
+#define TWCR_ACK TWCR           = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
 // send no ACK after recieving a byte / No ACK is expected after transmitting a byte
-#define TWCR_NACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(0<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
+#define TWCR_NACK TWCR          = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(0<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
 // switched to the non adressed slave mode
-#define TWCR_RESET TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
+#define TWCR_RESET TWCR         = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
 // The bit pattern for TWCR_ACK and TWCR_RESET are equal. This is no errro but used for better understanding.
-#define TWCR_CLEARBUS TWCR =(1<<TWEA) | (1<<TWSTO) | (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
+#define TWCR_CLEARBUS TWCR      = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(1<<TWSTO)|(0<<TWWC)
 ISR (TWI_vect)
+{
         uint8_t data;
         // check event
         switch (TW_STATUS)
+        {
         case TW_SR_SLA_ACK: // slave addressed in receiver mode and ack has been returned
             Rx_Idx = 0xFF;  // reset rx buffer pointer
                         TWCR_ACK;       // trigger receiving of first data byte and send ack afterwards
+                        LED_GRN_TOGGLE;
             return;
         case TW_SR_DATA_ACK: // data has been received and ack has been returned
                 data = TWDR;
                         if (Rx_Idx  == 0xFF)
                         {       // if the fisrt byte after slave addressing was received
                                 switch(data)
+                                {
                                         case I2C_CMD_VERSION:
                                                 I2C_TxBuffer = (uint8_t *)&I2C_Version;
                                                 I2C_TxBufferSize = sizeof(I2C_Version);
+                                                I2C_RxBuffer = 0;
                                                 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:
-                                        case I2C_CMD_WRITE_CAL:
+                                                I2C_TxBuffer = 0;
                                                 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_RxBuffer = 0;
                                                 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;
-                                        default:
+                                        default: // unknown command id
                                                 I2C_RxBuffer = 0;
                                                 I2C_RxBufferSize = 0;
                                                 I2C_TxBuffer = 0;
                                                 I2C_TxBufferSize = 0;
                                         break;
+                                }
                                 Rx_Idx = 0; // set rx buffer index to start of the buffer
-                                if(I2C_RxBufferSize > 1) TWCR_ACK; // prepare receiving of next byte and send ACK afterwards
-                                else TWCR_NACK; // prepare receiving of next byte and send NACK afterwards
+                        }
                         else // Rx_Idx  != 0xFF
+                        {
-                                // fill receiver buffer with byte that has been received
+                                // fill receiver buffer with the byte that has been received
-                                // if buffer exist
-                                if(I2C_RxBuffer != 0)
-                                {       // and there is still some free space
+                                // if buffer exist and there is still some free space
-                                        if (Rx_Idx  < I2C_RxBufferSize) I2C_RxBuffer[Rx_Idx++] = data;
+                                if((I2C_RxBuffer != 0) && (Rx_Idx  < I2C_RxBufferSize))
-                                        // if there is space for more than one byte
+                                {
-                                        if(Rx_Idx < (I2C_RxBufferSize - 1)) TWCR_ACK;
+                                        I2C_RxBuffer[Rx_Idx++] = data;
-                                        // with the next incomming byte the rx buffer is full
-                                        else TWCR_NACK;
+                                }
-                                // rx buffer does not exist
+                                // else ignore the data
-                                else TWCR_NACK; // prepare receiving of next byte and send NACK afterwards
+                        }
+                        TWCR_ACK;
             return;
-        case TW_SR_DATA_NACK: // data has been received and NACK has been returned
-                // read the last byte that is expected
-                data = TWDR;
-                if((I2C_RxBuffer != 0) && (Rx_Idx != 0xFF))
-                        {       // and there is still some free space
-                                if (Rx_Idx  < I2C_RxBufferSize) I2C_RxBuffer[Rx_Idx++] = data;
-                        }
-                        TWCR_RESET; // switched to the non adressed slave mode
-                return;
         case TW_ST_SLA_ACK: // slave transmitter selected
-                // reset position in tx buffer
+                // reset index  to start of tx buffer
             Tx_Idx = 0;
-                case TW_ST_DATA_ACK: // data byte has been transmitted ack has been received
-                        // put next byte from tx buffer to twi data register
+            // if tx bufer exist and there is at least ine byte to transfer
-                        if(I2C_TxBuffer != 0)
+                        if((I2C_TxBuffer != 0) && (I2C_TxBufferSize > 1))
-                        {
-                if (Tx_Idx < I2C_TxBufferSize)
-                {
+                        {
-                                        TWDR = I2C_TxBuffer[Tx_Idx++];
-                                        if(Tx_Idx + 1 < I2C_TxBufferSize) TWCR_ACK; // more than one byte to send
-                                        else TWCR_NACK; // last byte was send NACK should be received
-                                }
-                                else
-                                {   //
-                                        TWDR = 0x00;
-                                        TWCR_NACK;// NACK should be received
                                 TWDR = I2C_TxBuffer[Tx_Idx++];
+                        }
+                        else
+                        {   // send 0x00 if no tx buffer exist or all bytes of the tx buffer have been transmitted
+                                TWDR = 0x00;
+                        }
+                        TWCR_ACK;
+            return;
-                        }
+                case TW_ST_DATA_ACK: // data byte has been transmitted ack has been received
+                        // put next byte from tx buffer to the data register
-                        else // buffer not existent
+                        if((I2C_TxBuffer != 0) && (Tx_Idx < I2C_TxBufferSize))
+                        {
+                        TWDR = I2C_TxBuffer[Tx_Idx++];
+                        }
+                        else
                         {   // send dummy byte instead
-                                TWDR = 0x00;
-                                TWCR_NACK;// NACK should be received
+                                TWDR = 0x00;
+                        }
                         TWCR_ACK;
             return;
         case TW_BUS_ERROR:  // Bus-Error
-            TWCR_CLEARBUS;      // free bus reset to nonselected slave
+            TWCR_CLEARBUS;      // free bus, reset to nonselected slave
             return;
                 case TW_ST_DATA_NACK:   // data transmitted, NACK received
                 case TW_ST_LAST_DATA:   // last data byte transmitted, ACK received
                 case TW_SR_STOP:                // stop or repeated start condition received while selected
                 default:
                         TWCR_RESET; // switch to the not addressed slave mode, own SLA will be recognized
                 return;
+        }
+}

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(root)/branches/MK3Mag V0.14 Code Redesign Killagreg/twislave.c - Rev 22 → 23