Software / API Bindings / C/C++ / API Reference and Examples / Bricks / ESP32 Ethernet Brick

C/C++ - ESP32 Ethernet Brick¶

This is the description of the C/C++ API bindings for the ESP32 Ethernet Brick. General information and technical specifications for the ESP32 Ethernet Brick are summarized in its hardware description.

An installation guide for the C/C++ API bindings is part of their general description.

API¶

Most functions of the C/C++ bindings return an error code (e_code). Data returned from the device, when a getter is called, is handled via output parameters. These parameters are labeled with the ret_ prefix.

Possible error codes are:

E_OK = 0
E_TIMEOUT = -1
E_NO_STREAM_SOCKET = -2
E_HOSTNAME_INVALID = -3
E_NO_CONNECT = -4
E_NO_THREAD = -5
E_NOT_ADDED = -6 (unused since C/C++ bindings version 2.0.0)
E_ALREADY_CONNECTED = -7
E_NOT_CONNECTED = -8
E_INVALID_PARAMETER = -9
E_NOT_SUPPORTED = -10
E_UNKNOWN_ERROR_CODE = -11
E_STREAM_OUT_OF_SYNC = -12
E_INVALID_UID = -13
E_NON_ASCII_CHAR_IN_SECRET = -14
E_WRONG_DEVICE_TYPE = -15
E_DEVICE_REPLACED = -16
E_WRONG_RESPONSE_LENGTH = -17

as defined in ip_connection.h.

All functions listed below are thread-safe.

Advanced Functions¶

int esp32_ethernet_get_identity(ESP32Ethernet *esp32_ethernet, char ret_uid[8], char ret_connected_uid[8], char *ret_position, uint8_t ret_hardware_version[3], uint8_t ret_firmware_version[3], uint16_t *ret_device_identifier)¶

Parameters:	esp32_ethernet – Type: ESP32Ethernet *
Output Parameters:	ret_uid – Type: char[8] ret_connected_uid – Type: char[8] ret_position – Type: char, Range: ['0' to '8'] ret_hardware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_firmware_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255] ret_device_identifier – Type: uint16_t, Range: [0 to 2¹⁶ - 1]
Returns:	e_code – Type: int

Returns the UID, the UID where the Brick is connected to, the position, the hardware and firmware version as well as the device identifier.

The position is the position in the stack from '0' (bottom) to '8' (top).

The device identifier numbers can be found here. There is also a constant for the device identifier of this Brick.

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

int esp32_ethernet_get_api_version(ESP32Ethernet *esp32_ethernet, uint8_t ret_api_version[3])¶

Parameters:	esp32_ethernet – Type: ESP32Ethernet *
Output Parameters:	ret_api_version – Type: uint8_t[3] 0: major – Type: uint8_t, Range: [0 to 255] 1: minor – Type: uint8_t, Range: [0 to 255] 2: revision – Type: uint8_t, Range: [0 to 255]
Returns:	e_code – Type: int

Returns the version of the API definition implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

int esp32_ethernet_get_response_expected(ESP32Ethernet *esp32_ethernet, uint8_t function_id, bool *ret_response_expected)¶

Parameters:	esp32_ethernet – Type: ESP32Ethernet * function_id – Type: uint8_t, Range: See constants
Output Parameters:	ret_response_expected – Type: bool
Returns:	e_code – Type: int

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by esp32_ethernet_set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For function_id:

int esp32_ethernet_set_response_expected(ESP32Ethernet *esp32_ethernet, uint8_t function_id, bool response_expected)¶

Parameters:	esp32_ethernet – Type: ESP32Ethernet * function_id – Type: uint8_t, Range: See constants response_expected – Type: bool
Returns:	e_code – Type: int

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

The following constants are available for this function:

For function_id:

int esp32_ethernet_set_response_expected_all(ESP32Ethernet *esp32_ethernet, bool response_expected)¶

Parameters:	esp32_ethernet – Type: ESP32Ethernet * response_expected – Type: bool
Returns:	e_code – Type: int

Changes the response expected flag for all setter and callback configuration functions of this device at once.

Constants¶

ESP32_ETHERNET_DEVICE_IDENTIFIER¶

This constant is used to identify a ESP32 Ethernet Brick.

The esp32_ethernet_get_identity() function and the IPCON_CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

ESP32_ETHERNET_DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a ESP32 Ethernet Brick.