WebSVN - FlightCtrl - Blame - Rev 2248 - /branches/V0.76g_dk9nw

Rev	Author	Line No.	Line
2248	-	1	/*****************************************************************************************************************************
		2	* File: twimaster.c
		3	*
		4	* Purpose: setup of I2C (TWI)
		5	*
		6	* Functions: extern void i2c_init (void); // initialize I2C
		7	* extern void i2c_start (void); // Start I2C
		8	* extern void i2c_reset(void); // resert I2C
		9	* extern void i2c_stop (void); // Stop I2C
		10	* extern void i2c_write_byte (char byte); // write 1 Byte
		11	*
		12	*****************************************************************************************************************************/
		13	#include "twimaster.h"
		14	#include "main.h"
		15
		16	volatile unsigned char twi_state = 0;
		17	unsigned char motor=0;
		18	unsigned char motorread=0, MissingMotor=0;
		19	unsigned char motor_rx[16], motor_rx2[16];
		20	unsigned char MotorPresent[MAX_MOTORS]; // #define MAX_MOTORS 4
		21	unsigned char MotorError[MAX_MOTORS];
		22	unsigned int I2CError=0;
		23
		24
		25	// *************************************************************************************************************************************
		26	// Initzialize I2C (TWI)
		27	//
		28	void i2c_init(void)
		29	{
		30	//--------------------------------------------------------------------------------------------------------------------
		31	// TWSR = TWI Status Register containing: TWS7 TWS6 TWS5 TWS4 TWS3 � TWPS1 TWPS0
		32	//
		33	TWSR = 0; // TWSR � TWI Status Register
		34
		35	//--------------------------------------------------------------------------------------------------------------------
		36	// TWBR = TWI Bit Rate Register containing: TWBR7 TWBR6 TWBR5 TWBR4 TWBR3 TWBR2 TWBR1 TWBR0
		37	// set TWI Bit Rate Register // SYSCLK = 16000000 and SCL_CLOCK = 200000
		38	TWBR = ((SYSCLK/SCL_CLOCK)-16)/2; // selects the division factor for the bit rate generator
		39	}
		40	// *************************************************************************************************************************************
		41
		42
		43
		44	//-------------------------------------------------------------------------------------------------------------------------------------
		45	// Start I2C
		46	//
		47	void i2c_start(void)
		48	{
		49	// ---------------------------------------------------------------------------
		50	// TWCR = TWI Control Register -> TWINT TWEA TWSTA TWSTO TWWC TWEN � TWIE
		51	// TWINT = TWI interrupt flag - to be set to one, to reset the TWINT Flag
		52	// TWSTA = TWI start and should be set to one, that TWI is started as Master.
		53	// TWEN = TWI enable -> now TWI/I2C is working properly.
		54	// TWIE = TWI Interrupt enable is the TWIE Bit -> should be set
		55	//
		56	TWCR = (1<<TWINT)\|(1<<TWSTA)\|(1<<TWEN)\|(1<<TWIE);
		57	}
		58	//-------------------------------------------------------------------------------------------------------------------------------------
		59
		60
		61
		62	//-------------------------------------------------------------------------------------------------------------------------------------
		63	// Stop I2C
		64	//
		65	void i2c_stop(void)
		66	{
		67	// ---------------------------------------------------------------------------
		68	// TWCR = TWI Control Register -> TWINT TWEA TWSTA TWSTO TWWC TWEN � TWIE
		69	// TWINT = TWI interrupt flag - to be set to one, to reset the TWINT Flag
		70	// TWSTO = TWI STOP Condition Bit (TWSTO = 1) -> now will be stoped
		71	// TWEN = TWI enable -> TWI/I2C is working properly
		72	//
		73	TWCR = (1<<TWINT)\|(1<<TWSTO)\|(1<<TWEN);
		74	}
		75	//-------------------------------------------------------------------------------------------------------------------------------------
		76
		77
		78
		79	//-------------------------------------------------------------------------------------------------------------------------------------
		80	// I2C Reset
		81	//
		82	void i2c_reset(void)
		83	{
		84	i2c_stop();
		85	twi_state = 0;
		86	motor = TWDR; // TWI Data Register (TWDR) siehe S 227
		87	motor = 0; // ist das letzte gesendete oder empfangene Byte
		88	TWCR = 0x80;
		89	TWAMR = 0;
		90	TWAR = 0;
		91	TWDR = 0;
		92	TWSR = 0;
		93	TWBR = 0;
		94	i2c_init();
		95	i2c_start();
		96	i2c_write_byte(0);
		97	}
		98	//-------------------------------------------------------------------------------------------------------------------------------------
		99
		100
		101
		102	//---------------------------------------------------------------------------------------------------------------------------------------------
		103	// write via I2C
		104	//
		105	void i2c_write_byte(char byte)
		106	{
		107	TWSR = 0x00;
		108	TWDR = byte; // sende dieses Byte via TWI Data Register
		109	TWCR = (1<<TWINT) \| (1<<TWEN) \| (1<<TWIE);
		110	}
		111	//---------------------------------------------------------------------------------------------------------------------------------------------
		112
		113
		114
		115	//---------------------------------------------------------------------------------------------------------------------------------------------
		116	// write byte via I2C
		117	//
		118	void I2C_WriteByte(int8_t byte)
		119	{
		120	// move byte to send into TWI Data Register
		121	TWDR = byte;
		122	// clear interrupt flag (TWINT = 1)
		123	// enable i2c bus (TWEN = 1)
		124	// enable interrupt (TWIE = 1)
		125	TWCR = (1<<TWINT) \| (1<<TWEN) \| (1<<TWIE);
		126	}
		127	//---------------------------------------------------------------------------------------------------------------------------------------------
		128
		129
		130
		131	//---------------------------------------------------------------------------------------------------------------------------------------------
		132	// ein Byte gelesen und sendet ACK
		133	//
		134	void I2C_ReceiveByte(void)
		135	{
		136	TWCR = (1<<TWINT) \| (1<<TWEN) \| (1<<TWIE) \| (1<<TWEA);
		137	}
		138	//---------------------------------------------------------------------------------------------------------------------------------------------
		139
		140
		141
		142	//---------------------------------------------------------------------------------------------------------------------------------------------
		143	// I2C empfing das letzte Byte und sendet kein ACK
		144	//
		145	void I2C_ReceiveLastByte(void)
		146	{
		147	TWCR = (1<<TWINT) \| (1<<TWEN) \| (1<<TWIE);
		148	}
		149	//---------------------------------------------------------------------------------------------------------------------------------------------
		150
		151
		152
		153	//-----------------------------------------------------------------------------------------------------------------------------------------------
		154	// Interrupt I2C
		155	//
		156	ISR (TWI_vect)
		157	{
		158	static unsigned char missing_motor;
		159
		160	switch(twi_state++)
		161	{
		162	//----------------------------------------------------------------------------------------------------------------------------
		163	// write Motor-Data
		164	//----------------------------------------------------------------------------------------------------------------------------
		165	case 0:
		166	while(Mixer.Motor[motor][0] <= 0 && motor < MAX_MOTORS) motor++; // #define MAX_MOTORS 2
		167	if(motor == MAX_MOTORS) // writing finished -> now read
		168	{
		169	motor = 0;
		170	twi_state = 3;
		171	if(motorread==0) i2c_write_byte(0x53); // Read-Adress of: Motor 1 = 0x53 / 2 = 0x55 / 3 = 0x57 / 4 = 0x59
		172	if(motorread==1) i2c_write_byte(0x57);
		173	}
		174	else
		175	{
		176	if(motor==0) i2c_write_byte(0x52); // Write-Adress of: Motor 1 = 0x52 / 2 = 0x54 / 3 = 0x56 / 4 = 0x58
		177	if(motor==1) i2c_write_byte(0x56);
		178	}
		179	break;
		180
		181	case 1:
		182	i2c_write_byte(Motor[motor++]);
		183	break;
		184
		185	case 2:
		186	// TWSR � TWI Status Register -> TWS7 TWS6 TWS5 TWS4 TWS3 - TWPS1 TWPS0
		187	// Data byte has been transmitted; NOT ACK has been received
		188	if(TWSR == 0x30)
		189	{
		190	if(!missing_motor) missing_motor = motor; //
		191	if(++MotorError[motor-1] == 0) MotorError[motor-1] = 255; //
		192	}
		193
		194	i2c_stop();
		195	I2CTimeout = 10; // counted down every 2ms = watchdog
		196	twi_state = 0;
		197	i2c_start();
		198	break;
		199
		200	//----------------------------------------------------------------------------------------------------------
		201	// read Motor-Data
		202	//----------------------------------------------------------------------------------------------------------
		203	case 3:
		204	if(TWSR != 0x40) // Error?
		205	{ // send 1. Byte to be read
		206	MotorPresent[motorread] = 0;
		207	motorread++;
		208	if(motorread >= MAX_MOTORS) motorread = 0; // #define MAX_MOTORS 2
		209	i2c_stop();
		210	twi_state = 0;
		211	}
		212	else
		213	{
		214	MotorPresent[motorread] = ('1' - '-') + motorread;
		215	I2C_ReceiveByte();
		216	}
		217	//MissingMotor = missing_motor;
		218	MissingMotor = 0;
		219	missing_motor = 0;
		220	break;
		221
		222	case 4: // read 1. Byte and send 2. Byte
		223	motor_rx[motorread] = TWDR;
		224	I2C_ReceiveLastByte(); // no acknowledge
		225	break;
		226
		227	case 5:
		228	motor_rx2[motorread++] = TWDR; // read 2. Byte
		229	if(motorread >= MAX_MOTORS) motorread = 0; // #define MAX_MOTORS 4
		230	i2c_stop();
		231	twi_state = 0;
		232	break;
		233
		234	//----------------------------------------------------------------------------------------------------------------------------------
		235	// write Gyro-Offset
		236	//----------------------------------------------------------------------------------------------------------------------------------
		237	case 8:
		238	i2c_write_byte(0x98); // Address of DAC see DAC Manual page 17
		239	break;
		240
		241	case 9:
		242	i2c_write_byte(0x10); // byte sent to chanel A
		243	break;
		244
		245	case 10:
		246	i2c_write_byte(AnalogOffsetNick); // offset sent to DAC
		247	break;
		248
		249	case 11:
		250	i2c_write_byte(0x80); // The 2nd Byte does not care = 0x80 (Dummy)
		251	break;
		252
		253	case 12:
		254	i2c_stop();
		255	I2CTimeout = 10;
		256	i2c_start();
		257	break;
		258
		259	case 13:
		260	i2c_write_byte(0x98); // Address of DAC see DAC Manual page 17
		261	break;
		262
		263	case 14:
		264	i2c_write_byte(0x12); // byte sent to chanel B
		265	break;
		266
		267	case 15:
		268	i2c_write_byte(AnalogOffsetRoll); // offset sent to DAC
		269	break;
		270
		271	case 16:
		272	i2c_write_byte(0x80); // The 2nd Byte does not care = 0x80 (Dummy)
		273	break;
		274
		275	case 17:
		276	i2c_stop();
		277	I2CTimeout = 10;
		278	i2c_start();
		279	break;
		280
		281	case 18:
		282	i2c_write_byte(0x98); // Address of DAC see DAC Manual page 17
		283	break;
		284
		285	case 19:
		286	i2c_write_byte(0x14); // byte sent to chanel C
		287	break;
		288
		289	case 20:
		290	i2c_write_byte(AnalogOffsetGier); // offset sent to DAC
		291	break;
		292
		293	case 21:
		294	i2c_write_byte(0x80); // The 2nd Byte does not care = 0x80 (Dummy)
		295	break;
		296
		297	case 22:
		298	i2c_stop();
		299	I2CTimeout = 10;
		300	twi_state = 0;
		301	break;
		302
		303	default: twi_state = 0;
		304	break;
		305	}
		306	TWCR \|= 0x80; // TWWC: TWI Write Collision Flag is set to 1
		307	}
		308	//-----------------------------------------------------------------------------------------------------------------------------------

Subversion Repositories FlightCtrl

(root)/branches/V0.76g_dk9nw_balancekopter/twimaster.c - Rev 2248