Method get_grove_value

Software/C/GoPiGo3.cpp:488–567

}

int GoPiGo3::get_grove_value(uint8_t port, void *value_ptr){
  uint8_t msg_type;
  uint8_t port_index;
  switch(port){
    case GROVE_1:
      msg_type = GPGSPI_MESSAGE_GET_GROVE_VALUE_1;
      port_index = 0;
    break;
    case GROVE_2:
      msg_type = GPGSPI_MESSAGE_GET_GROVE_VALUE_2;
      port_index = 1;
    break;
    default:
      fatal_error("get_grove_value error. Must be one grove port at a time. GROVE_1 or GROVE_2.");
  }
  spi_array_out[0] = Address;
  spi_array_out[1] = msg_type;

  uint8_t spi_transfer_length;

  // Determine the SPI transaction byte length based on the grove type
  switch(GroveType[port_index]){
    case GROVE_TYPE_IR_DI_REMOTE:
      spi_transfer_length = 7;
    break;
    case GROVE_TYPE_IR_EV3_REMOTE:
      spi_transfer_length = 10;
    break;
    case GROVE_TYPE_US:
      spi_transfer_length = 8;
    break;
    case GROVE_TYPE_I2C:
      spi_transfer_length = 6 + GroveI2CInBytes[port_index];
    break;
    default:
      return GROVE_STATUS_NOT_CONFIGURED;
    break;
  }

  // Get the grove value(s), and if error
  // assign error to the value returned by spi_transfer_array, and if not 0:
  if(int error = spi_transfer_array(spi_transfer_length, spi_array_out, spi_array_in)){
    return error;
  }
  // If the fourth byte received is not 0xA5
  if(spi_array_in[3] != 0xA5){
    return ERROR_SPI_RESPONSE;
  }
  // If the grove type is not what it should be
  if(spi_array_in[4] != GroveType[port_index]){
    printf("get_grove_value %d != %d for port index %d\n", spi_array_in[4], GroveType[port_index], port_index);
    return ERROR_GROVE_TYPE_MISMATCH;
  }
  // If the sensor value(s) is not valid (still configuring the grove port, or error communicating with grove device)
  if(spi_array_in[5] != GROVE_STATUS_VALID_DATA){
    return spi_array_in[5];
  }