uint8_t I2C::read(uint8_t address, uint8_t registerAddress, uint8_t numberBytes, uint8_t *dataBuffer)
{
bytesAvailable = 0;
bufferIndex = 0;
if(numberBytes == 0){numberBytes++;}
nack = numberBytes - 1;
returnStatus = 0;
returnStatus = start();
if(returnStatus){return(returnStatus);}
returnStatus = sendAddress(SLA_W(address));
if(returnStatus)
{
if(returnStatus == 1){return(2);}
return(returnStatus);
}
returnStatus = sendByte(registerAddress);
if(returnStatus)
{
if(returnStatus == 1){return(3);}
return(returnStatus);
}
returnStatus = start();
if(returnStatus)
{
if(returnStatus == 1){return(4);}
return(returnStatus);
}
returnStatus = sendAddress(SLA_R(address));
if(returnStatus)
{
if(returnStatus == 1){return(5);}
return(returnStatus);
}
for(uint8_t i = 0; i < numberBytes; i++)
{
if( i == nack )
{
returnStatus = receiveByte(0);
if(returnStatus == 1){return(6);}
if(returnStatus != MR_DATA_NACK){return(returnStatus);}
}
else
{
returnStatus = receiveByte(1);
if(returnStatus == 1){return(6);}
if(returnStatus != MR_DATA_ACK){return(returnStatus);}
}
dataBuffer[i] = TWDR;
bytesAvailable = i+1;
totalBytes = i+1;
}
returnStatus = stop();
if(returnStatus)
{
if(returnStatus == 1){return(7);}
return(returnStatus);
}
return(returnStatus);
}
bool read_registers_uint16_le(uint8_t addr, uint8_t reg, uint16_t* data, uint8_t size)
{
QASSERT(s_is_initialized);
QASSERT(s_is_locked);
QASSERT(data && size > 0);
if (!data || size == 0)
{
return 0;
}
uint8_t* data_ptr8 = reinterpret_cast<uint8_t*>(data) + 1;
//the data_ptr8 will advance like this
//1, 0, 3, 2, 5, 4, 7, 6, 9, 8
if (!_start()) goto error;
if (!_send_address(SLA_W(addr))) goto error;
if (!_send_byte(reg)) goto error;
if (!_start()) goto error;
if (!_send_address(SLA_R(addr))) goto error;
{
uint8_t i = size - 1;
while (i > 0)
{
if (!_receive_byte_ack()) goto error;
*data_ptr8 = TWDR;
data_ptr8 -= 1;
if (!_receive_byte_ack()) goto error;
*data_ptr8 = TWDR;
data_ptr8 += 3;
--i;
}
}
//last bytes
{
if (!_receive_byte_ack()) goto error;
*data_ptr8 = TWDR;
data_ptr8 -= 1;
if (!_receive_byte()) goto error;
*data_ptr8 = TWDR;
//data_ptr8 += 3;
}
if (!_stop()) goto error;
return true;
error:
s_lockup_count++;
return false;
}
bool read_registers(uint8_t addr, uint8_t reg, uint8_t* data, uint8_t size)
{
QASSERT(s_is_initialized);
QASSERT(s_is_locked);
QASSERT(size > 0);
if (size == 0)
{
return 0;
}
if (!_start()) goto error;
if (!_send_address(SLA_W(addr))) goto error;
if (!_send_byte(reg)) goto error;
if (!_start()) goto error;
if (!_send_address(SLA_R(addr))) goto error;
if (data)
{
uint8_t i = size - 1;
while (i > 0)
{
if (!_receive_byte_ack()) goto error;
*data++ = TWDR;
--i;
}
//last item
{
if (!_receive_byte()) goto error;
*data = TWDR;
}
}
else
{
uint8_t i = size - 1;
while (i > 0)
{
if (!_receive_byte_ack()) goto error;
s_i2c_null_sink = TWDR;
--i;
}
//last item
{
if (!_receive_byte()) goto error;
s_i2c_null_sink = TWDR;
}
}
if (!_stop()) goto error;
return true;
error:
s_lockup_count++;
return false;
}
bool read(uint8_t addr, uint8_t* data, uint8_t size)
{
QASSERT(s_is_initialized);
QASSERT(s_is_locked);
QASSERT(size > 0);
if (size == 0)
{
return 0;
}
if (!_start()) goto error;
if (!_send_address(SLA_R(addr))) goto error;
if (data)
{
for (int8_t i = size - 1; i > 0; i--) //write size - 1 butes
{
if (!_receive_byte_ack()) goto error;
*data++ = TWDR;
}
//last item
{
if (!_receive_byte()) goto error;
*data = TWDR;
}
}
else
{
for (int8_t i = size - 1; i > 0; i--) //write size - 1 butes
{
if (!_receive_byte_ack()) goto error;
s_i2c_null_sink = TWDR;
}
//last item
{
if (!_receive_byte()) goto error;
s_i2c_null_sink = TWDR;
}
}
if (!_stop()) goto error;
return true;
error:
s_lockup_count++;
return false;
}