uchar twi_read(uchar W_ADDRESS)
{
uchar temp;
START(); //TWI启动
WAIT();
if (SATUS()!=_START)
return TRUE;
TWI_WRITE(W_MPU6050_ADDR); //写 MPU6050地址和写方式
WAIT();
if (SATUS()!=MT_SLA_ACK)
return TRUE;
TWI_WRITE(W_ADDRESS); //写 MPU6050相应寄存器地址
WAIT();
if (SATUS()!=MT_DATA_ACK)
return TRUE;
START(); //TWI重新启动
WAIT();
if (SATUS()!=RE_START)
return TRUE;
TWI_WRITE(R_MPU6050_ADDR); //写 MPU6050地址和读方式
WAIT();
if(SATUS()!=MR_SLA_ACK)
return TRUE;
TWI_READ(); //启动主TWI读方式
WAIT();
if(SATUS()!=MR_DATA_NOACK)//读完一个数停止接收数据 ，主机接收到不再接收应答信号 ，如果继续接收到应答信号
return TRUE; //说明主机继续接收数据则为错误
temp=TWDR; //读取 TWI接收数据
STOP(); //TWI停止
return temp;
}
bool _moduloTransfer(
uint8_t address, uint8_t command, uint8_t *sendData, uint8_t sendLen,
uint8_t *receiveData, uint8_t receiveLen, bool receiveString)
{
// Star the transmit CRC with the address in the upper 7 bits
uint8_t crc = _crc8_ccitt_update(0, address);
TWI_BEGIN_WRITE(address);
// Send the command and length
TWI_WRITE(command);
TWI_WRITE(sendLen);
crc = _crc8_ccitt_update(crc, command);
crc = _crc8_ccitt_update(crc, sendLen);
// Send the data
for (int i=0; i < sendLen; i++) {
TWI_WRITE(sendData[i]);
crc = _crc8_ccitt_update(crc, sendData[i]);
}
// Send the CRC and end the transmission
TWI_WRITE(crc);
if (TWI_END_WRITE(receiveLen == 0) != 0) {
return false;
}
if (receiveLen == 0) {
return true;
}
while (TWI_AVAILABLE()) {
TWI_READ();
}
// Request receiveLen data bytes plus 1 CRC byte.
if (TWI_REQUEST_FROM((int)address, (int)receiveLen+1) != receiveLen+1) {
return false;
}
// Start the CRC with the I2C address byte (address in upper 7, 1 in lsb)
crc = _crc8_ccitt_update(0, address);
// Receive the data
for (int i=0; i < receiveLen; i++) {
receiveData[i] = TWI_READ();
// If we're receiving a string, then stop when we find a 0 byte.
if (receiveString and i > 0 and receiveData[i-1] == 0) {
return (receiveData[i] == crc);
}
crc = _crc8_ccitt_update(crc, receiveData[i]);
}
// Receive the CRC.
uint8_t receivedCRC = TWI_READ();
// Check the CRC.
return (crc == receivedCRC);
}
