Subversion Repositories MK3Mag

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12 hbuss 1
/*#######################################################################################
2
MK3Mag 3D-Magnet sensor
19 killagreg 3
!!! THIS IS NOT FREE SOFTWARE !!!
12 hbuss 4
#######################################################################################*/
5
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
6
// + Copyright (c) 05.2008 Holger Buss
7
// + Thanks to Ilja Fähnrich (P_Latzhalter)
8
// + Nur für den privaten Gebrauch
9
// + www.MikroKopter.com
10
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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
29
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
30
// + Die Funktion printf_P() unterliegt ihrer eigenen Lizenz und ist hiervon nicht betroffen
31
// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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
36
// +     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
41
// +     Exception: A preassembled MK3Mag, purchased from www.mikrokopter.de may be used as a part of commercial systems
42
// +     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
44
// +     clearly linked as origin
12 hbuss 45
// +  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
46
// +  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47
// +  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48
// +  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
49
// +  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
50
// +  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
51
// +  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
52
// +  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
53
// +  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
54
// +  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
 
22 killagreg 67
uint8_t I2C_RxBufferSize = 0, I2C_TxBufferSize = 0;
68
uint8_t *I2C_TxBuffer = 0, *I2C_RxBuffer = 0;
69
uint8_t Tx_Idx = 0, Rx_Idx = 0;
3 ingob 70
 
71
 
72
 
19 killagreg 73
I2C_Heading_t       I2C_Heading;
74
I2C_WriteAttitude_t I2C_WriteAttitude;
75
I2C_Mag_t           I2C_Mag;
76
I2C_EEPROM_t        I2C_ReadEEPROM, I2C_WriteEEPROM;
77
I2C_Version_t       I2C_Version;
78
I2C_WriteCal_t      I2C_WriteCal;
79
 
80
 
81
void I2C_Init(void)
82
{
22 killagreg 83
 
84
        uint8_t sreg;
85
 
86
        // backup status register
87
        sreg = SREG;
88
    // disable global interrupts
19 killagreg 89
        cli();
90
 
22 killagreg 91
        // SCK/SCL and  MISO/SDA are at put together on the same connector pin in the schematic
19 killagreg 92
 
22 killagreg 93
        // set PB4 (SCK) and PB5 (MISO) as input tristate
19 killagreg 94
        DDRB &= ~((1<<DDB4)|(1<<DDB5));
22 killagreg 95
        PORTB &= ~((1<<PORTB4)|(1<<PORTB5));
19 killagreg 96
 
22 killagreg 97
        // set PC4 (SDA) and PC5 (SCL) as input tristate
19 killagreg 98
        DDRC &= ~((1<<DDC4)|(1<<DDC5));
22 killagreg 99
        PORTC &= ~((1<<PORTC4)|(1<<PORTC5));
19 killagreg 100
 
22 killagreg 101
        I2C_TxBuffer = 0;
102
        Tx_Idx = 0;
103
        I2C_TxBufferSize = 0;
104
        I2C_RxBuffer = 0;
105
        Rx_Idx = 0;
106
        I2C_RxBufferSize = 0;
107
 
108
 
109
 
110
        TWCR &= ~(1<<TWSTA)|(1<<TWSTO);
111
        TWCR|= (1<<TWEA) | (1<<TWEN)|(1<<TWIE);
112
 
113
        // set own address
114
        // set own address in the upper 7 bits
115
    TWAR = I2C_SLAVE_ADDRESS; // set own address only the upper 7 bits are relevant
19 killagreg 116
        // TWI Control Register
117
        // enable TWI Acknowledge Bit (TWEA = 1)
118
        // disable TWI START Condition Bit (TWSTA = 0), SLAVE
22 killagreg 119
        // disable TWI  STOP Condition Bit (TWSTO = 0), SLAVE
120
        // enable TWI (TWEN = 1)
19 killagreg 121
        // enable TWI Interrupt (TWIE = 1)
22 killagreg 122
        TWCR &= ~((1<<TWSTA)|(1<<TWSTO));
123
        TWCR |= (1<<TWEA)|(1<<TWEN)|(1<<TWIE);
124
 
19 killagreg 125
        // update version info
126
        I2C_Version.Major = VERSION_MAJOR;
127
        I2C_Version.Minor = VERSION_MINOR;
128
        I2C_Version.Compatible = I2C_PROTOCOL_COMP;
129
 
22 killagreg 130
        // resore status register
19 killagreg 131
        SREG = sreg;
1 ingob 132
}
19 killagreg 133
 
22 killagreg 134
// send ACK after recieving a byte / ACK is expected after transmitting a byte
3 ingob 135
#define TWCR_ACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
22 killagreg 136
// send no ACK after recieving a byte / No ACK is expected after transmitting a byte
137
#define TWCR_NACK TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(0<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
138
// switched to the non adressed slave mode
139
#define TWCR_RESET TWCR = (1<<TWEN)|(1<<TWIE)|(1<<TWINT)|(1<<TWEA)|(0<<TWSTA)|(0<<TWSTO)|(0<<TWWC)
140
// The bit pattern for TWCR_ACK and TWCR_RESET are equal. This is no errro but used for better understanding.
141
#define TWCR_CLEARBUS TWCR =(1<<TWEA) | (1<<TWSTO) | (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
19 killagreg 142
 
1 ingob 143
ISR (TWI_vect)
19 killagreg 144
{
22 killagreg 145
        uint8_t data;
19 killagreg 146
        // check event
22 killagreg 147
        switch (TW_STATUS)
19 killagreg 148
        {
22 killagreg 149
        case TW_SR_SLA_ACK: // slave addressed in receiver mode and ack has been returned
150
            Rx_Idx = 0xFF;  // reset rx buffer pointer
151
                        TWCR_ACK;       // trigger receiving of first data byte and send ack afterwards
1 ingob 152
            return;
19 killagreg 153
 
22 killagreg 154
        case TW_SR_DATA_ACK: // data has been received and ack has been returned
155
                data = TWDR;
156
                        if (Rx_Idx  == 0xFF)
157
                        {       // if the fisrt byte after slave addressing was received
158
                                switch(data)
19 killagreg 159
                                {
160
                                        case I2C_CMD_VERSION:
161
                                                I2C_TxBuffer = (uint8_t *)&I2C_Version;
3 ingob 162
                                                I2C_TxBufferSize = sizeof(I2C_Version);
163
                                                I2C_RxBufferSize = 0;
19 killagreg 164
                                                break;
165
 
166
                                        case I2C_CMD_WRITE_EEPROM:
3 ingob 167
                                                I2C_TxBufferSize = 0;
19 killagreg 168
                                                I2C_RxBuffer = (uint8_t *)&I2C_WriteEEPROM;
3 ingob 169
                                                I2C_RxBufferSize = sizeof(I2C_WriteEEPROM);
19 killagreg 170
                                                break;
7 hbuss 171
 
19 killagreg 172
                                        case I2C_CMD_WRITE_CAL:
7 hbuss 173
                                                I2C_TxBufferSize = 0;
19 killagreg 174
                                                I2C_RxBuffer = (uint8_t *)&I2C_WriteCal;
7 hbuss 175
                                                I2C_RxBufferSize = sizeof(I2C_WriteCal);
19 killagreg 176
                                                break;
7 hbuss 177
 
19 killagreg 178
                                        case I2C_CMD_READ_EEPROM:
179
                                                I2C_TxBuffer = (uint8_t *)&I2C_ReadEEPROM.Content;
3 ingob 180
                                                I2C_TxBufferSize = 2;
19 killagreg 181
                                                I2C_RxBuffer = (uint8_t *)&I2C_ReadEEPROM;
3 ingob 182
                                                I2C_RxBufferSize = 1;
19 killagreg 183
                                                break;
184
 
185
                                        case I2C_CMD_READ_MAG:
186
                                                I2C_TxBuffer = (uint8_t *)&I2C_Mag;
3 ingob 187
                                                I2C_TxBufferSize = sizeof(I2C_Mag);
188
                                                I2C_RxBufferSize = 0;
19 killagreg 189
 
190
                                                I2C_Mag.MagX = MagnetX;
191
                                                I2C_Mag.MagY = MagnetY;
3 ingob 192
                                                I2C_Mag.MagZ = MagnetZ;
19 killagreg 193
                                                break;
194
 
195
                                        case I2C_CMD_READ_HEADING:
196
                                                I2C_TxBuffer = (uint8_t *)&I2C_Heading;
3 ingob 197
                                                I2C_TxBufferSize = sizeof(I2C_Heading);
19 killagreg 198
                                                I2C_RxBuffer =  (uint8_t *)&I2C_WriteAttitude;
199
                                                I2C_RxBufferSize = sizeof(I2C_WriteAttitude);
200
                                                // update heading from global variable
3 ingob 201
                                                I2C_Heading.Heading = Heading;
19 killagreg 202
                                                // copy current attitude from I2C rx buffer to uart rx buffer (this is used for the calulation of the heading)
203
                                                ExternData.Attitude[NICK] = I2C_WriteAttitude.Nick;
204
                                                ExternData.Attitude[ROLL] = I2C_WriteAttitude.Roll;
205
                                                break;
22 killagreg 206
                                        default:
207
                                                I2C_RxBuffer = 0;
208
                                                I2C_RxBufferSize = 0;
209
                                                I2C_TxBuffer = 0;
210
                                                I2C_TxBufferSize = 0;
211
                                        break;
19 killagreg 212
                                }
22 killagreg 213
                                Rx_Idx = 0; // set rx buffer index to start of the buffer
214
                                if(I2C_RxBufferSize > 1) TWCR_ACK; // prepare receiving of next byte and send ACK afterwards
215
                                else TWCR_NACK; // prepare receiving of next byte and send NACK afterwards
3 ingob 216
                        }
22 killagreg 217
                        else // Rx_Idx  != 0xFF
3 ingob 218
                        {
22 killagreg 219
                                // fill receiver buffer with byte that has been received
220
                                // if buffer exist
221
                                if(I2C_RxBuffer != 0)
222
                                {       // and there is still some free space
223
                                        if (Rx_Idx  < I2C_RxBufferSize) I2C_RxBuffer[Rx_Idx++] = data;
224
                                        // if there is space for more than one byte
225
                                        if(Rx_Idx < (I2C_RxBufferSize - 1)) TWCR_ACK;
226
                                        // with the next incomming byte the rx buffer is full
227
                                        else TWCR_NACK;
228
                                }
229
                                // rx buffer does not exist
230
                                else TWCR_NACK; // prepare receiving of next byte and send NACK afterwards
3 ingob 231
                        }
1 ingob 232
            return;
19 killagreg 233
 
22 killagreg 234
        case TW_SR_DATA_NACK: // data has been received and NACK has been returned
235
                // read the last byte that is expected
236
                data = TWDR;
237
                if((I2C_RxBuffer != 0) && (Rx_Idx != 0xFF))
238
                        {       // and there is still some free space
239
                                if (Rx_Idx  < I2C_RxBufferSize) I2C_RxBuffer[Rx_Idx++] = data;
240
                        }
241
                        TWCR_RESET; // switched to the non adressed slave mode
242
                return;
243
 
244
        case TW_ST_SLA_ACK: // slave transmitter selected
19 killagreg 245
                // reset position in tx buffer
3 ingob 246
            Tx_Idx = 0;
22 killagreg 247
                case TW_ST_DATA_ACK: // data byte has been transmitted ack has been received
248
                        // put next byte from tx buffer to twi data register
249
                        if(I2C_TxBuffer != 0)
250
                        {
251
                if (Tx_Idx < I2C_TxBufferSize)
252
                {
253
                                        TWDR = I2C_TxBuffer[Tx_Idx++];
254
                                        if(Tx_Idx + 1 < I2C_TxBufferSize) TWCR_ACK; // more than one byte to send
255
                                        else TWCR_NACK; // last byte was send NACK should be received
256
                                }
257
                                else
258
                                {   //
259
                                        TWDR = 0x00;
260
                                        TWCR_NACK;// NACK should be received
261
                                }
262
                        }
263
                        else // buffer not existent
264
                        {
265
                                TWDR = 0x00;
266
                                TWCR_NACK;// NACK should be received
267
                        }
19 killagreg 268
            return;
269
 
22 killagreg 270
        case TW_BUS_ERROR:  // Bus-Error
271
            TWCR_CLEARBUS;      // free bus reset to nonselected slave
19 killagreg 272
            return;
273
 
22 killagreg 274
                case TW_ST_DATA_NACK:   // data transmitted, NACK received
275
                case TW_ST_LAST_DATA:   // last data byte transmitted, ACK received
276
                case TW_SR_STOP:                // stop or repeated start condition received while selected
277
                default:
278
                        TWCR_RESET; // switch to the not addressed slave mode, own SLA will be recognized
279
                return;
19 killagreg 280
        }
1 ingob 281
}
282
 
283