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12 hbuss 1
/*#######################################################################################
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MK3Mag 3D-Magnet sensor
19 killagreg 3
!!! THIS IS NOT FREE SOFTWARE !!!
12 hbuss 4
#######################################################################################*/
5
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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// + Copyright (c) 05.2008 Holger Buss
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// + Thanks to Ilja Fähnrich (P_Latzhalter)
8
// + Nur für den privaten Gebrauch
9
// + www.MikroKopter.com
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// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
19 killagreg 11
// + Die Portierung der Software (oder Teile davon) auf andere Systeme (ausser der Hardware von www.mikrokopter.de) ist nur
12 hbuss 12
// + mit unserer Zustimmung zulässig
13
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
19 killagreg 14
// + Es gilt für das gesamte Projekt (Hardware, Software, Binärfiles, Sourcecode und Dokumentation),
15
// + dass eine Nutzung (auch auszugsweise) nur für den privaten (nicht-kommerziellen) Gebrauch zulässig ist.
12 hbuss 16
// + AUSNAHME: Ein bei www.mikrokopter.de erworbener vorbestückter MK3Mag darf als Baugruppe auch in kommerziellen Systemen verbaut werden
17
// + Im Zweifelsfall bitte anfragen bei: info@mikrokopter.de
18
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
19 killagreg 19
// + Werden Teile des Quellcodes (mit oder ohne Modifikation) weiterverwendet oder veröffentlicht,
12 hbuss 20
// + unterliegen sie auch diesen Nutzungsbedingungen und diese Nutzungsbedingungen incl. Copyright müssen dann beiliegen
21
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
22
// + Sollte die Software (auch auszugesweise) oder sonstige Informationen des MikroKopter-Projekts
23
// + auf anderen Webseiten oder sonstigen Medien veröffentlicht werden, muss unsere Webseite "http://www.mikrokopter.de"
24
// + eindeutig als Ursprung verlinkt werden
25
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
26
// + Keine Gewähr auf Fehlerfreiheit, Vollständigkeit oder Funktion
27
// + Benutzung auf eigene Gefahr
28
// + Wir übernehmen keinerlei Haftung für direkte oder indirekte Personen- oder Sachschäden
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// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
30
// + Die Funktion printf_P() unterliegt ihrer eigenen Lizenz und ist hiervon nicht betroffen
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// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
19 killagreg 32
// + Redistributions of source code (with or without modifications) must retain the above copyright notice,
12 hbuss 33
// + this list of conditions and the following disclaimer.
34
// +   * PORTING this software (or parts of it) to systems (other than hardware from www.mikrokopter.de) is NOT allowed
35
// +   * Neither the name of the copyright holders nor the names of contributors may be used to endorse or promote products derived
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// +     from this software without specific prior written permission.
19 killagreg 37
// +   * The use of this project (hardware, software, binary files, sources and documentation) is only permittet
12 hbuss 38
// +     for non-commercial use (directly or indirectly)
19 killagreg 39
// +     Commercial use (for excample: selling of MikroKopters, selling of PCBs, assembly, ...) is only permitted
12 hbuss 40
// +     with our written permission
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// +     Exception: A preassembled MK3Mag, purchased from www.mikrokopter.de may be used as a part of commercial systems
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// +     In case of doubt please contact: info@MikroKopter.de
19 killagreg 43
// +   * If sources or documentations are redistributet on other webpages, our webpage (http://www.MikroKopter.de) must be
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// +     clearly linked as origin
12 hbuss 45
// +  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// +  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// +  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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// +  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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// +  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// +  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// +  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// +  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
19 killagreg 55
// +  POSSIBILITY OF SUCH DAMAGE.
12 hbuss 56
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 ingob 57
#include <avr/io.h>
19 killagreg 58
#include <avr/interrupt.h>
1 ingob 59
#include <util/twi.h>
19 killagreg 60
#include "twislave.h"
61
#include "uart.h"
1 ingob 62
#include "main.h"
19 killagreg 63
#include "timer0.h"
22 killagreg 64
#include "led.h"
1 ingob 65
 
66
 
23 killagreg 67
volatile uint8_t I2C_RxBufferSize = 0, I2C_TxBufferSize = 0;
68
volatile uint8_t *I2C_TxBuffer = 0, *I2C_RxBuffer = 0;
69
volatile uint8_t Tx_Idx = 0, Rx_Idx = 0;
3 ingob 70
 
71
 
72
 
23 killagreg 73
struct I2C_Heading_t       I2C_Heading;
74
struct I2C_WriteAttitude_t I2C_WriteAttitude;
75
struct I2C_Mag_t           I2C_Mag;
76
struct I2C_Version_t       I2C_Version;
77
struct I2C_WriteCal_t      I2C_WriteCal;
19 killagreg 78
 
79
 
80
void I2C_Init(void)
81
{
22 killagreg 82
 
83
        uint8_t sreg;
84
 
85
        // backup status register
86
        sreg = SREG;
87
    // disable global interrupts
19 killagreg 88
        cli();
89
 
22 killagreg 90
        // SCK/SCL and  MISO/SDA are at put together on the same connector pin in the schematic
19 killagreg 91
 
23 killagreg 92
        // set PB4 (SCK) and PB5 (MISO) as input pull up
19 killagreg 93
        DDRB &= ~((1<<DDB4)|(1<<DDB5));
23 killagreg 94
        PORTB |= ((1<<PORTB4)|(1<<PORTB5));
19 killagreg 95
 
22 killagreg 96
        // set PC4 (SDA) and PC5 (SCL) as input tristate
19 killagreg 97
        DDRC &= ~((1<<DDC4)|(1<<DDC5));
22 killagreg 98
        PORTC &= ~((1<<PORTC4)|(1<<PORTC5));
19 killagreg 99
 
22 killagreg 100
        I2C_TxBuffer = 0;
101
        Tx_Idx = 0;
102
        I2C_TxBufferSize = 0;
103
        I2C_RxBuffer = 0;
104
        Rx_Idx = 0;
105
        I2C_RxBufferSize = 0;
106
 
107
 
108
 
109
        TWCR &= ~(1<<TWSTA)|(1<<TWSTO);
110
        TWCR|= (1<<TWEA) | (1<<TWEN)|(1<<TWIE);
111
 
112
        // set own address
113
        // set own address in the upper 7 bits
114
    TWAR = I2C_SLAVE_ADDRESS; // set own address only the upper 7 bits are relevant
19 killagreg 115
        // TWI Control Register
116
        // enable TWI Acknowledge Bit (TWEA = 1)
117
        // disable TWI START Condition Bit (TWSTA = 0), SLAVE
22 killagreg 118
        // disable TWI  STOP Condition Bit (TWSTO = 0), SLAVE
119
        // enable TWI (TWEN = 1)
19 killagreg 120
        // enable TWI Interrupt (TWIE = 1)
23 killagreg 121
        TWCR |= (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(1<<TWSTO)|(0<<TWWC);
19 killagreg 122
        // update version info
123
        I2C_Version.Major = VERSION_MAJOR;
124
        I2C_Version.Minor = VERSION_MINOR;
125
        I2C_Version.Compatible = I2C_PROTOCOL_COMP;
126
 
22 killagreg 127
        // resore status register
19 killagreg 128
        SREG = sreg;
1 ingob 129
}
19 killagreg 130
 
22 killagreg 131
// send ACK after recieving a byte / ACK is expected after transmitting a byte
23 killagreg 132
#define TWCR_ACK TWCR           = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
22 killagreg 133
// send no ACK after recieving a byte / No ACK is expected after transmitting a byte
23 killagreg 134
#define TWCR_NACK TWCR          = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(0<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
22 killagreg 135
// switched to the non adressed slave mode
23 killagreg 136
#define TWCR_RESET TWCR         = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
22 killagreg 137
// The bit pattern for TWCR_ACK and TWCR_RESET are equal. This is no errro but used for better understanding.
23 killagreg 138
#define TWCR_CLEARBUS TWCR      = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(1<<TWSTO)|(0<<TWWC)
19 killagreg 139
 
1 ingob 140
ISR (TWI_vect)
19 killagreg 141
{
22 killagreg 142
        uint8_t data;
23 killagreg 143
 
19 killagreg 144
        // check event
22 killagreg 145
        switch (TW_STATUS)
19 killagreg 146
        {
22 killagreg 147
        case TW_SR_SLA_ACK: // slave addressed in receiver mode and ack has been returned
148
            Rx_Idx = 0xFF;  // reset rx buffer pointer
149
                        TWCR_ACK;       // trigger receiving of first data byte and send ack afterwards
23 killagreg 150
                        LED_GRN_TOGGLE;
1 ingob 151
            return;
19 killagreg 152
 
22 killagreg 153
        case TW_SR_DATA_ACK: // data has been received and ack has been returned
154
                data = TWDR;
155
                        if (Rx_Idx  == 0xFF)
156
                        {       // if the fisrt byte after slave addressing was received
157
                                switch(data)
19 killagreg 158
                                {
159
                                        case I2C_CMD_VERSION:
160
                                                I2C_TxBuffer = (uint8_t *)&I2C_Version;
3 ingob 161
                                                I2C_TxBufferSize = sizeof(I2C_Version);
23 killagreg 162
                                                I2C_RxBuffer = 0;
3 ingob 163
                                                I2C_RxBufferSize = 0;
19 killagreg 164
                                                break;
165
 
166
                                        case I2C_CMD_WRITE_CAL:
23 killagreg 167
                                                I2C_TxBuffer = 0;
7 hbuss 168
                                                I2C_TxBufferSize = 0;
19 killagreg 169
                                                I2C_RxBuffer = (uint8_t *)&I2C_WriteCal;
7 hbuss 170
                                                I2C_RxBufferSize = sizeof(I2C_WriteCal);
19 killagreg 171
                                                break;
7 hbuss 172
 
19 killagreg 173
                                        case I2C_CMD_READ_MAG:
174
                                                I2C_TxBuffer = (uint8_t *)&I2C_Mag;
3 ingob 175
                                                I2C_TxBufferSize = sizeof(I2C_Mag);
23 killagreg 176
                                                I2C_RxBuffer = 0;
3 ingob 177
                                                I2C_RxBufferSize = 0;
19 killagreg 178
 
179
                                                I2C_Mag.MagX = MagnetX;
180
                                                I2C_Mag.MagY = MagnetY;
3 ingob 181
                                                I2C_Mag.MagZ = MagnetZ;
19 killagreg 182
                                                break;
183
 
184
                                        case I2C_CMD_READ_HEADING:
185
                                                I2C_TxBuffer = (uint8_t *)&I2C_Heading;
3 ingob 186
                                                I2C_TxBufferSize = sizeof(I2C_Heading);
19 killagreg 187
                                                I2C_RxBuffer =  (uint8_t *)&I2C_WriteAttitude;
188
                                                I2C_RxBufferSize = sizeof(I2C_WriteAttitude);
189
                                                // update heading from global variable
3 ingob 190
                                                I2C_Heading.Heading = Heading;
19 killagreg 191
                                                // copy current attitude from I2C rx buffer to uart rx buffer (this is used for the calulation of the heading)
192
                                                ExternData.Attitude[NICK] = I2C_WriteAttitude.Nick;
193
                                                ExternData.Attitude[ROLL] = I2C_WriteAttitude.Roll;
194
                                                break;
23 killagreg 195
                                        default: // unknown command id
22 killagreg 196
                                                I2C_RxBuffer = 0;
197
                                                I2C_RxBufferSize = 0;
198
                                                I2C_TxBuffer = 0;
199
                                                I2C_TxBufferSize = 0;
200
                                        break;
19 killagreg 201
                                }
22 killagreg 202
                                Rx_Idx = 0; // set rx buffer index to start of the buffer
3 ingob 203
                        }
22 killagreg 204
                        else // Rx_Idx  != 0xFF
3 ingob 205
                        {
23 killagreg 206
                                // fill receiver buffer with the byte that has been received
207
                                // if buffer exist and there is still some free space
208
                                if((I2C_RxBuffer != 0) && (Rx_Idx  < I2C_RxBufferSize))
209
                                {
210
                                        I2C_RxBuffer[Rx_Idx++] = data;
22 killagreg 211
                                }
23 killagreg 212
                                // else ignore the data
3 ingob 213
                        }
23 killagreg 214
                        TWCR_ACK;
1 ingob 215
            return;
19 killagreg 216
 
23 killagreg 217
        case TW_ST_SLA_ACK: // slave transmitter selected
218
                // reset index  to start of tx buffer
219
            Tx_Idx = 0;
220
            // if tx bufer exist and there is at least ine byte to transfer
221
                        if((I2C_TxBuffer != 0) && (I2C_TxBufferSize > 1))
222
                        {
223
                                TWDR = I2C_TxBuffer[Tx_Idx++];
22 killagreg 224
                        }
23 killagreg 225
                        else
226
                        {   // send 0x00 if no tx buffer exist or all bytes of the tx buffer have been transmitted
227
                                TWDR = 0x00;
228
                        }
229
                        TWCR_ACK;
230
            return;
22 killagreg 231
 
232
                case TW_ST_DATA_ACK: // data byte has been transmitted ack has been received
23 killagreg 233
                        // put next byte from tx buffer to the data register
234
                        if((I2C_TxBuffer != 0) && (Tx_Idx < I2C_TxBufferSize))
22 killagreg 235
                        {
23 killagreg 236
                        TWDR = I2C_TxBuffer[Tx_Idx++];
22 killagreg 237
                        }
23 killagreg 238
                        else
239
                        {   // send dummy byte instead
22 killagreg 240
                                TWDR = 0x00;
241
                        }
23 killagreg 242
                        TWCR_ACK;
19 killagreg 243
            return;
244
 
22 killagreg 245
        case TW_BUS_ERROR:  // Bus-Error
23 killagreg 246
            TWCR_CLEARBUS;      // free bus, reset to nonselected slave
19 killagreg 247
            return;
248
 
22 killagreg 249
                case TW_ST_DATA_NACK:   // data transmitted, NACK received
250
                case TW_ST_LAST_DATA:   // last data byte transmitted, ACK received
251
                case TW_SR_STOP:                // stop or repeated start condition received while selected
252
                default:
253
                        TWCR_RESET; // switch to the not addressed slave mode, own SLA will be recognized
254
                return;
19 killagreg 255
        }
1 ingob 256
}
257
 
258