void
I2c_Transmit(int n)
{
if (n > I2C_BufferSz)
return ;
i2cBuff[0] &= ~0x01; // fix address , this is the "write" I2C address now
i2cm_start();
// TODO: need to check for ack and return false if no ACK
i2cm_out( i2cBuff, n+1); // sending device address + data to slave
i2cm_stop(); // transition bus into idle state
}
// returns one of I2C_ACK, I2C_NAK, I2C_MISSING_SCL_PULLUP or I2C_MISSING_SDA_PULLUP
uint8_t i2cm_txbyte(const uint8_t slave_address, const uint8_t data)
{
uint8_t rv;
rv = i2cm_start();
if (rv != I2C_OK) {
return rv;
}
rv = i2cm_tx(slave_address, I2C_WRITE);
if (rv == I2C_ACK) {
rv = i2cm_tx(data, I2C_NO_ADDR_SHIFT);
}
i2cm_stop();
return rv;
}
// returns one of I2C_ACK, I2C_NAK, I2C_MISSING_SCL_PULLUP or I2C_MISSING_SDA_PULLUP
uint8_t i2cm_rxfrom(const uint8_t slave_address, uint8_t * data,
uint16_t length)
{
uint8_t rv;
rv = i2cm_start();
if (rv != I2C_OK) {
return rv;
}
rv = i2cm_tx(slave_address, I2C_READ);
if (rv == I2C_ACK) {
i2cm_rx(data, length, 0);
}
i2cm_stop();
return rv;
}
void
I2c_Receive(int n) // Read transaction from slave
{
if (n > I2C_BufferSz)
return ;
i2cBuff[0] &= ~0x01; // Write address first
i2cm_start(); // transition from idle state into start condition
i2cm_out( i2cBuff, 2); // device address and command address in write mode
// i2cm_stop(); // not needed
i2cBuff[0] |= 0x01; // Set Read mode address bit
i2cm_start(); // restart for read phase
i2cm_out( i2cBuff, 1); // Device addressed in read mode now
i2cm_in ( i2cBuff, n); // Reads from slave with ACK from master
i2cm_stop(); // transition bus into idle state
return;
}
