int Wii_Data( nunchuck_data_t *data )
{
int i = 0x21;
if (data == 0)
return -1;
// send 0x00 to let nunchuck know we are going to request data
i2c_start(); // send start
i2c_sendByte(WII_ADDR);
i2c_sendByte(0x00);
i2c_stop();
// switch to read mode by adding 1 to WII_ADDR
_delay_ms(1);
i2c_start(); // send start
i2c_sendByte(WII_ADDR | 1);
uint8_t *packet = (uint8_t*)data;
for(i = 0; i < 6; i++)
{
if(i < 5)
{
i2c_ack();
}
else
{
i2c_nack();
}
*(packet+i) = i2c_getByte();
}
i2c_stop();
return i;
}
i2c_interrupt() {
static uint8_t addrFailCnt;
SOS_MEASUREMENT_IDLE_END();
// TWSR & TW_STATUS_MASK
switch (TWSR) {
/*************************
* Master General States *
*************************/
case TWI_START: /* 0x08 */
addrFailCnt = 0;
i2c.idx = 0;
// Fall through!
case TWI_REP_START: /* 0x10 */
i2c_setByte(i2c.addr|((i2c.flags & I2C_TX_FLAG)?0:1)); // only set R/W bit if reading
i2c_setCtrlReg((1<<TWINT)|(1<<TWEN)|(1<<TWIE));
break;
case TWI_ARB_LOST: /* 0x38 */
i2c_setCtrlReg((1<<TWINT)|(1<<TWSTA)|(1<<TWEN)|(1<<TWIE)); // Initate a (RE)START condition
// TWI hardware will resend start when bus is free and signal TWI_RESTART
break;
/*****************************
* Master Transmitter States *
*****************************/
case TWI_MTX_ADR_ACK: /* 0x18 */
i2c.state = I2C_MASTER_TX;
if (i2c.flags & I2C_SOS_MSG_FLAG) {
// this is a difference between the i2c and uart
// uart uses a protocol byte for BOTH raw and sos_msgs
// i2c ONLY sends a protocol byte in the case of a sos_msg
i2c_setByte(HDLC_SOS_MSG);
i2c.msg_state = SOS_MSG_TX_HDR;
// this is a sos_msg so a crc is required
i2c.crc = crcByte(0, HDLC_SOS_MSG);
i2c_setCtrlReg((1<<TWINT)|(1<<TWEN)|(1<<TWIE));
break;
} else {
i2c.msg_state = SOS_MSG_TX_RAW;
} // fall through
case TWI_MTX_DATA_ACK: /* 0x28 */
switch (i2c.msg_state) {
case SOS_MSG_TX_HDR:
i2c_setByte(((uint8_t*)(i2c.msgBuf))[i2c.idx]);
// this is a sos_msg so a crc is required
i2c.crc = crcByte(i2c.crc, ((uint8_t*)(i2c.msgBuf))[i2c.idx]);
i2c.idx++;
if (i2c.idx == SOS_MSG_HEADER_SIZE) {
i2c.idx = 0;
i2c.txPending = i2c.msgLen + SOS_MSG_CRC_SIZE;
i2c.msg_state = SOS_MSG_TX_DATA;
}
break;
case SOS_MSG_TX_RAW:
case SOS_MSG_TX_DATA:
i2c_setByte(i2c.dataBuf[i2c.idx]);
if (i2c.flags & I2C_CRC_FLAG) {
i2c.crc = crcByte(i2c.crc, i2c.dataBuf[i2c.idx]);
}
i2c.idx++;
if (i2c.idx == i2c.msgLen) {
if (!(i2c.flags & I2C_CRC_FLAG)) {
// send stop bit and reset interface to ready state
i2c.txPending = 0;
i2c.msg_state = SOS_MSG_TX_END;
} else {
i2c.txPending = SOS_MSG_CRC_SIZE; // no unsent bytes
i2c.msg_state = SOS_MSG_TX_CRC_LOW;
}
}
break;
case SOS_MSG_TX_CRC_LOW:
i2c_setByte((uint8_t)(i2c.crc));
i2c.txPending--;
i2c.msg_state = SOS_MSG_TX_CRC_HIGH;
break;
case SOS_MSG_TX_CRC_HIGH:
i2c_setByte((uint8_t)(i2c.crc>>8));
i2c.txPending--;
i2c.msg_state = SOS_MSG_TX_END;
break;
case SOS_MSG_TX_END:
// send stop bit and reset interface to ready state
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWSTO)|(1<<TWEN)|(1<<TWIE));
i2c_send_done(i2c.flags);
i2c.state = restoreState();
return;
default:
break;
}
// normal send byte all stop conditions must return and not get here
i2c_setCtrlReg((1<<TWINT)|(1<<TWEN)|(1<<TWIE));
break;
case TWI_MTX_ADR_NACK: /* 0x20 */
if (addrFailCnt++ < MAX_ADDR_FAIL) {
// try restarting MAX_ADDR_FAIL times then fail
i2c_setCtrlReg((1<<TWINT)|(1<<TWSTA)|(1<<TWEN)|(1<<TWIE));
} else {
// reset i2c and send msg fail to process
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWSTO)|(1<<TWEN)|(1<<TWIE));
i2c_send_done(i2c.flags|I2C_ERROR_FLAG);
i2c.state = restoreState();
}
break;
case TWI_MTX_DATA_NACK: /* 0x30 */
// reset i2c and send msg fail to process
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWSTO)|(1<<TWEN)|(1<<TWIE));
i2c.txPending = i2c.txPending - i2c.idx + 1; // last byte failed
i2c_send_done(i2c.flags|I2C_BUFF_ERR_FLAG);
i2c.state = restoreState();
break;
/***************************
* Master Receiver States *
***************************/
case TWI_MRX_ADR_ACK: /* 0x40 */
i2c.state = I2C_MASTER_RX;
i2c.rxStatus = i2c.flags;
// all master rx are done in raw mode with NO protocol byte
i2c.msg_state = SOS_MSG_RX_RAW;
// a sos message will never be recieved as a manster
if (i2c.msgLen == 1) {
i2c.msg_state = SOS_MSG_RX_END;
i2c_setCtrlReg((1<<TWINT)|(1<<TWEN)|(1<<TWIE));
} else {
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
}
break;
case TWI_MRX_DATA_ACK: /* 0x50 */
i2c.dataBuf[i2c.idx++] = i2c_getByte();
if (i2c.idx < (i2c.msgLen-1)) {
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
} else { // unset TWEA (Send NACK after next/last byte)
i2c.msg_state = SOS_MSG_RX_END;
i2c_setCtrlReg((1<<TWINT)|(1<<TWEN)|(1<<TWIE));
}
break;
case TWI_MRX_ADR_NACK: /* 0x48 */
if (addrFailCnt++ < MAX_ADDR_FAIL) {
// tryrestarting MAX_ADDR_FAIL times then fail
i2c_setCtrlReg((1<<TWINT)|(1<<TWSTA)|(1<<TWEN)|(1<<TWIE));
break;
}
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWSTO)|(1<<TWEN)|(1<<TWIE));
// return data
i2c_read_done(i2c.dataBuf, i2c.idx, i2c.rxStatus);
i2c.idx = 0;
i2c.rxStatus = 0;
i2c.state = restoreState();
break;
case TWI_MRX_DATA_NACK: /* 0x58 */
i2c.dataBuf[i2c.idx++] = i2c_getByte();
if (i2c.idx < i2c.msgLen) {
// nack from master indication rx done
// send stop bit, clear interrupt and reset interface to ready state
i2c.rxStatus |= I2C_BUFF_ERR_FLAG;
}
// set flags and return data
i2c.rxStatus |= I2C_BUFF_DIRTY_FLAG;
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWSTO)|(1<<TWEN)|(1<<TWIE));
i2c_read_done(i2c.dataBuf, i2c.idx, i2c.rxStatus);
i2c.idx = 0;
i2c.rxStatus = 0;
i2c.state = restoreState();
break;
/****************************
* Slave Transmitter States *
****************************/
case TWI_STX_ADR_ACK: /* 0xA8 */
case TWI_STX_ADR_ACK_M_ARB_LOST: /* 0xB0 */
if (i2c.state != I2C_SLAVE_WAIT) {
i2c_send_done(i2c.flags|I2C_ERROR_FLAG);
break;
} else {
saveState(i2c.state);
i2c.state = I2C_SLAVE_TX;
i2c.msg_state = SOS_MSG_TX_RAW;
}
// fall through
case TWI_STX_DATA_ACK: /* 0xB8 */
if (i2c.msg_state == SOS_MSG_TX_RAW) {
i2c_setByte(i2c.dataBuf[i2c.idx++]);
// unset TWEA (Send NACK after next/last byte)
if (i2c.msgLen == i2c.idx) {
i2c_setCtrlReg((1<<TWINT)|(1<<TWEN)|(1<<TWIE));
i2c.txPending = 1; // last byte failed
i2c.msg_state = SOS_MSG_TX_END;
} else { // Reset the TWI Interupt to wait to ack next byte
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
}
}
break;
case TWI_STX_DATA_NACK: /* 0xC0 */
// Master has sent a NACK before expected amount of data was sent.
// set dirty bit on send buffer go to end state and issue send done
if (i2c.msg_state != SOS_MSG_TX_END) {
i2c.txPending = i2c.txPending - i2c.idx + 1; // last byte failed
i2c.msg_state = SOS_MSG_TX_END;
} else {
i2c.txPending = 0;
}
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
if (i2c.msg_state == SOS_MSG_TX_END) {
i2c.msg_state = SOS_MSG_NO_STATE;
i2c_send_done(i2c.flags);
}
break;
case TWI_STX_DATA_ACK_LAST_BYTE: /* 0xC8 */
i2c.msg_state = SOS_MSG_NO_STATE;
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
i2c_send_done(i2c.flags|I2C_BUFF_ERR_FLAG);
break;
/*************************
* Slave Receiver States *
*************************/
// all receptions are done in a raw mode
// if it is a sos message it it will be packed later
case TWI_SRX_GEN_ACK: /* 0x70 */
case TWI_SRX_GEN_ACK_M_ARB_LOST: /* 0x78 */
i2c.rxStatus = I2C_GEN_ADDR_FLAG;
// fall through
case TWI_SRX_ADR_ACK: /* 0x60 */
case TWI_SRX_ADR_ACK_M_ARB_LOST: /* 0x68 */
saveState(i2c.state);
i2c.state = I2C_SLAVE_RX;
i2c.msg_state = SOS_MSG_RX_RAW;
i2c.idx = 0;
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
break;
case TWI_SRX_ADR_DATA_ACK: /* 0x80 */
case TWI_SRX_GEN_DATA_ACK: /* 0x90 */
if (i2c.msg_state == SOS_MSG_RX_RAW) {
i2c.rxDataBuf[i2c.idx++] = i2c_getByte();
if (i2c.idx >= I2C_MAX_MSG_LEN) { // buffer overflow
i2c.msg_state = SOS_MSG_RX_END;
// set flags and return data
i2c.rxStatus |= (I2C_BUFF_DIRTY_FLAG|I2C_BUFF_ERR_FLAG);
i2c_read_done(i2c.rxDataBuf, i2c.idx, i2c.rxStatus);
i2c.idx = 0;
i2c.rxStatus = 0;
}
}
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
break;
case TWI_SRX_ADR_DATA_NACK: /* 0x88 */
case TWI_SRX_GEN_DATA_NACK: /* 0x98 */
// switch to not addressed mode
if (i2c.msg_state == SOS_MSG_RX_RAW) {
// set flags and return data
i2c.rxStatus |= I2C_BUFF_DIRTY_FLAG;
i2c_read_done(i2c.rxDataBuf, i2c.idx, i2c.rxStatus);
i2c.idx = 0;
i2c.rxStatus = 0;
i2c.msg_state = SOS_MSG_RX_END;
}
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
break;
case TWI_SRX_STOP_RESTART: /* 0xA0 */
// reset reciever
i2c.msg_state = SOS_MSG_NO_STATE;
if (i2c.idx > 0) {
// need to make sure data has been read
i2c.rxStatus |= I2C_BUFF_DIRTY_FLAG;
i2c_read_done(i2c.rxDataBuf, i2c.idx, i2c.rxStatus);
i2c.idx = 0;
i2c.rxStatus = 0;
}
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
i2c.state = restoreState();
break;
/***************
* Misc States *
***************/
//case TWI_NO_STATE: /* 0xF8 */
case TWI_BUS_ERROR: /* 0x00 */
default:
{
uint8_t twiStatus=0;
// Store TWSR and automatically sets clears noErrors bit.
twiStatus = TWSR;
// Clear TWINT and reset TWI Interface
i2c_setCtrlReg((1<<TWINT)|(1<<TWEA)|(1<<TWEN)|(1<<TWIE));
i2c.state = I2C_IDLE;
// should really be i2c_error
i2c_send_done(I2C_NULL_FLAG);
break;
}
}
}