twi_transmit.ino

/* 
 * Function twi_transmit
 * Desc     fills slave tx buffer with data
 *          must be called in slave tx event callback
 * Input    data: pointer to byte array
 *          length: number of bytes in array
 * Output   1 length too long for buffer
 *          2 not slave transmitter
 *          0 ok
 */
uint8_t twi_transmit(const uint8_t* data, uint8_t length)
{
  uint8_t i;

  // ensure data will fit into buffer
  if(TWI_BUFFER_LENGTH < length){
    return 1;
  }
  
  // ensure we are currently a slave transmitter
  if(TWI_STX != twi_state){
    return 2;
  }
  
  // set length and copy data into tx buffer
  twi_txBufferLength = length;
  for(i = 0; i < length; ++i){
    twi_txBuffer[i] = data[i];
  }
  
  return 0;
}