// ------------------------------------------------------------------------------------------------------
// Setup Master Transmit - initialize Tx buffer for transmit to slave at address
// return: none
// parameters:
// address = target 7bit slave address
//
void i2c_t3::beginTransmission(uint8_t address)
{
i2c->txBuffer[0] = (address << 1); // store target addr
i2c->txBufferLength = 1;
clearWriteError(); // clear any previous write error
i2c->currentStatus = I2C_WAITING; // reset status
}
//
// Originally, 'endTransmission' was an f(void) function.
// It has been modified to take one parameter indicating
// whether or not a STOP should be performed on the bus.
// Calling endTransmission(false) allows a sketch to
// perform a repeated start.
//
// WARNING: Nothing in the library keeps track of whether
// the bus tenure has been properly ended with a STOP. It
// is very possible to leave the bus in a hung state if
// no call to endTransmission(true) is made. Some I2C
// devices will behave oddly if they do not see a STOP.
//
uint8_t TwoWire::endTransmission(uint8_t sendStop)
{
/* Set direction to send for sending of address and data. */
uint8_t result = (uint8_t)getWriteError();
if(result != 0)
{
// reset tx buffer iterator vars
txBufferIndex = 0;
txBufferLength = 0;
// indicate that we are done transmitting
transmitting_master = false;
return 1;
}
uint32_t t0 = millis();
while(I2C_HAL_GetStatusFlag(instance, kI2CBusBusy) && !I2C_HAL_IsMaster(instance))
{
if(millis() - t0 >= 25)
return 4; //timeout
}
uint16_t slaveAddress;
slaveAddress = (txAddress << 1U) & 0x00FFU;
bool sent = sendAddress(slaveAddress);
//tx buffer also sent by interrupt
// reset tx buffer iterator vars
txBufferIndex = 0;
txBufferLength = 0;
// indicate that we are done transmitting
transmitting_master = false;
clearWriteError();
result = 4;
if(sent) //sent without timeout
{
if(master_state == MASTER_STATE_COMPLETE)
{
result = 0;
}
else if(master_state == MASTER_STATE_TX_NAK) //failed
{
result = (txBufferIndex == 0) ? 2 : 3; //address or data fail
sendStop = true;
}
if(sendStop)
{
I2C_HAL_SendStop(instance);
}
}
I2C_HAL_SetDirMode(instance, kI2CReceive);
return result;
}
void TwoWire::beginTransmission(uint8_t address)
{
// indicate that we are transmitting
transmitting_master = true;
// set address of targeted slave
txAddress = address;
// reset tx buffer iterator vars
txBufferIndex = 0;
txBufferLength = 0;
clearWriteError();
}
