ELClientSocket Class Reference

#include <ELClientSocket.h>

Public Member Functions
	ELClientSocket (ELClient *e)
	Class to send/receive data.
int	begin (const char *host, uint16_t port, uint8_t sock_mode, void(*userCb)(uint8_t resp_type, uint8_t client_num, uint16_t len, char *data)=0)
	Initialize communication to a remote server.
void	send (const char *data)
	Send null-terminated data to the remote server.
void	send (const char *data, int len)
	Send data to the remote server.
uint16_t	getResponse (uint8_t *resp_type, uint8_t *client_num, char *data, uint16_t maxLen)
	Retrieve response.
uint16_t	waitResponse (uint8_t *resp_type, uint8_t *client_num, char *data, uint16_t maxLen, uint32_t timeout=DEFAULT_SOCKET_TIMEOUT)
	Wait for the response.

Data Fields
int32_t	remote_instance

Detailed Description

Definition at line 40 of file ELClientSocket.h.

Constructor & Destructor Documentation

ELClientSocket()

ELClientSocket::ELClientSocket

(

ELClient *

e

)

Class to send/receive data.

ELClientSocket(ELClient *e)

The ELClientSocket class sends data over a Socket to a remote server or acts as a TCP socket server. Each instance is used to communicate with one server and multiple instances can be created to send to multiple servers. The ELClientSocket class does not support concurrent requests to the same server because only a single response can be recevied at a time and the responses of the two requests may arrive out of order.

Parameters

e	Pointer to ELClient. Check ELClient API documentation.

Example

ELClientSocket socket(&esp);

Definition at line 24 of file ELClientSocket.cpp.

Member Function Documentation

begin()

int ELClientSocket::begin	(	const char *	host,
		uint16_t	port,
		uint8_t	sock_mode,
		void(*)(uint8_t resp_type, uint8_t client_num, uint16_t len, char *data)	userCb = 0
	)

Initialize communication to a remote server.

begin(const char* host, uint16_t port, uint8_t sock_mode, void (*userCb)(uint8_t resp_type, uint8_t client_num, uint16_t len, char *data))

Initialize communication to a remote server, this communicates with esp-link but does not open a connection to the remote server.

Parameters

host	Host to be connected. Can be a URL or an IP address in the format of xxx.xxx.xxx.xxx .
port	Port to be used to send/receive packets. Port MUST NOT be 80, 23 or 2323, as these ports are already used by EL-CLIENT on the ESP8266
sock_mode	Set socket mode to SOCKET_TCP_CLIENT, SOCKET_TCP_CLIENT_LISTEN, SOCKET_TCP_SERVER or SOCKET_UDP
(*userCb)(uint8_t	resp_type, uint8_t client_num, uint16_t len, char *data) (optional) Pointer to callback function that is called if data after data has been sent, received or if an error occured

Warning

Port MUST NOT be 80, 23 or 2323, as these ports are already used by EL-CLIENT on the ESP8266. Max 4 connections are supported!

Example1

// Setup a simple client to send data and disconnect after data was sent
socketConnNum = socket.begin(socketServer, socketPort, SOCKET_TCP_CLIENT, socketCb);

Example2

// Setup a client to send data and wait for response from remote server
socketConnNum = socket.begin(socketServer, socketPort, SOCKET_TCP_CLIENT_LISTEN, socketCb);

Example3

// Setup a TCP server and wait for a client to connect
socketConnNum = socket.begin(socketServer, socketPort, SOCKET_TCP_SERVER, socketCb);

Example3

// Setup a TCP server and wait for a client to connect
socketConnNum = socket.begin(socketServer, socketPort, SOCKET_UDP, socketCb);

Definition at line 121 of file ELClientSocket.cpp.

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getResponse()

uint16_t ELClientSocket::getResponse	(	uint8_t *	resp_type,
		uint8_t *	client_num,
		char *	data,
		uint16_t	maxLen
	)

Retrieve response.

getResponse(uint8_t resp_type, uint8_t *client_num, char data, uint16_t maxLen)

Check if a response from the remote server was received, returns the number of send or received bytes, 0 if no response (may need to wait longer)

Parameters

resp_type	Pointer to response type. Is USERCB_SENT if packet was sent or USERCB_RECV if a packet was received.
client_num	Pointer to connection number. Can be used to distinguish between different socket clients.
data	Pointer to buffer for received packet
maxLen	Size of buffer for received packet. If the received packet is larger than the buffer, the received packet will be truncated.

Returns

uint16_t Size of received packet or number of sent bytes or 0 if no response

Example

#define BUFLEN 266
void loop()
{
    // process any callbacks coming from esp_link
    esp.Process();
    // Check if we received a packet or if the last send request has finished
    char response[BUFLEN];
    memset(response, 0, BUFLEN);
    uint8_t resp_type;
    uint8_t client_num;
    uint16_t len = socket.getResponse(&resp_type, &client_num, response, BUFLEN);
    if (len != 0)
    {
        if (resp_type == USERCB_SENT)
        {
            Serial.println("Sent "+String(len)+" bytes");
        }
        else
        {
            Serial.print("Received packet: ");
            for (int i=0; i<len; i++)
            {
                Serial.print(response[i]);
            }
            Serial.println("");
        }
    }
}

Definition at line 236 of file ELClientSocket.cpp.

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send() [1/2]

void ELClientSocket::send

(

const char *

data

)

Send null-terminated data to the remote server.

send(const char* data)

Parameters

data	Pointer to SOCKET packet, must be null-terminated

Example

Serial.println("Sending text message to SOCKET server");
socket.send("Message from your Arduino Uno WiFi over TCP socket");

Definition at line 184 of file ELClientSocket.cpp.

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send() [2/2]

void ELClientSocket::send	(	const char *	data,
		int	len
	)

Send data to the remote server.

send(const char* data, int len)

Parameters

data	Pointer to SOCKET packet
len	Length of SOCKET packet

Example

Serial.println("Sending JSON array to SOCKET server");
char socketPacket = "{"device":"spm","s":622.02,"c":-165.86}"
socket.send(socketPacket, 39);

Definition at line 160 of file ELClientSocket.cpp.

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waitResponse()

uint16_t ELClientSocket::waitResponse	(	uint8_t *	resp_type,
		uint8_t *	client_num,
		char *	data,
		uint16_t	maxLen,
		uint32_t	timeout = DEFAULT_SOCKET_TIMEOUT
	)

Wait for the response.

waitResponse(uint8_t resp_type, uint8_t *client_num, char data, uint16_t maxLen, uint32_t timeout)

Checks if a response from the remote server has arrived for timeout seconds, returns the number of send or received bytes, 0 if no response (may need to wait longer)

Warning

Blocks the Arduino code for 5 seconds! not recommended to use. Use callback function instead! Received packet is NOT null-terminated

Parameters

resp_type	Pointer to response type. Is USERCB_SENT if packet was sent or USERCB_RECV if a packet was received.
client_num	Pointer to connection number. Can be used to distinguish between different socket clients.
data	Pointer to buffer for received packet
maxLen	Size of buffer for received packet. If the received packet is larger than the buffer, the received packet will be truncated.
timeout	(optional) Timout in milli seconds to wait for a response, defaults to 5000ms

Returns

uint16_t Size of received packet or number of sent bytes or 0 if no response

Example

#define BUFLEN 266
bool haveRemoteResponse = true;
void loop()
{
    // process any callbacks coming from esp_link
    esp.Process();
    if (haveRemoteResponse) // If last packet was sent, send a new one
    {
        Serial.println("Sending JSON array to TCP server");
        char socketPacket = "{"device":"spm","s":622.02,"c":-165.86}"
        socket.send(socketPacket, 39);
        haveRemoteResponse = false;
    }
    // Check if we received a packet or if the last send request has finished
    char response[BUFLEN];
    memset(response, 0, BUFLEN);
    uint8_t resp_type;
    uint8_t client_num;
    uint16_t len = socket.waitResponse(&resp_type, &client_num, response, BUFLEN);
    if (len != 0)
    {
        if (resp_type == USERCB_SENT)
        {
            Serial.println("Sent "+String(len)+" bytes");
        }
        else
        {
            Serial.print("Received packet: ");
            for (int i=0; i<len; i++)
            {
                Serial.print(response[i]);
            }
            Serial.println("");
            haveRemoteResponse = true;
        }
    }
}

Definition at line 306 of file ELClientSocket.cpp.

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Field Documentation

remote_instance

int32_t ELClientSocket::remote_instance

Connection number, value can be 0 to 3

Definition at line 71 of file ELClientSocket.h.

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The documentation for this class was generated from the following files:

• Gbox420_Mega_Main/ELClient/ELClientSocket.h
• Gbox420_Mega_Main/ELClient/ELClientSocket.cpp