Add UDP socket client, TCP socket client & server

[beegee-tokyo]

I implemented UDP socket client, TCP socket client & server into esp-link & el-client. Code is still under testing, but working.

Are you interested to add this functionality into esp-link/el-client? If yes, I can send a pull-request to start discussion. Link to forks: esp-link el-client

[mhanuel26]

Hi beegee-tokyo,

Do you think I might use your port as a starting point to add websockets?

Please let me know,

[beegee-tokyo]

Yes, why not?

[mhanuel26]

Hello beegee-tokyo,

I know you are not maintaining the esp-link but since you actually have contribute I would like to ask you or anybody that might give me some comments,

I am not seeing any documentation that this library has SSL/TLS support, not sure the reason since the inspired repo of tuanpmt/espduino supports it.

Do you know the difficulties or constrains to have secure sockets or mqtts with esp-link?

I will appreciate your comments,

[rolfz]

Hello, Can I change the tcp/udp port on the web interface ? means it is not anymore limited to 23 and 2323 ?? and stored in eeprom ? It was on the prinding enhancement list...

[beegee-tokyo]

@rolfz: Ports 23 and 2323 are still used by used by the web interface. My UDP/TCP functions allow you to open a UDP socket or TCP socket connection to a remote server/client to transmit/receive data from the uC!. It has nothing to do with flashing a connected uC over the web interface.

You define the port you want to use when you call tcp.begin() or udp.begin(). Check the documentation TCP begin and UDP begin. You can see as well in my examples how to setup the port TCP client example 1 TCP client example 2 TCP server example UDP example

[rolfz]

Thank you Beegee, I did not explain myself correctly, my question was about changing the port inside the web configuration page. I want to connect a wifi interface to my telescope to communicate with TCP on socket 1000 in state of 23 or 2323. I understand the original firmware only supports TCP/UDP over socket 23/2323. Would it be possible to change the port over the config page or do I need to recompile the firmware to change the port number ??

[beegee-tokyo]

I am not working on anything to change the web-configuration pages, I only proposed to add some TCP/UDP socket connection functionality which can be controlled by the attached uC. I remember your request from the issues list, but I don't think my code will solve your problems unless you are willing to use the new functions to setup the connection to the telescope from within the uC (Arduino board I guess) application to send/receive the data directly to/from the telescope.

[mhanuel26]

Hello beegee-tokyo,

Would you mind to tell me the difficulties you foreseen make tcp/udp sockets or in general this project capable of SSL/TLS?

I will appreciate your response,

[beegee-tokyo]

@mhanuel26: Sorry, I can not answer you. I didn't look (yet) into the ESP SDK regarding support of SSL/TLS. If there is native support, it might be not too difficult.

[tve]

Closing since there's the pull request #188, please move discussions there. Thanks!!

[Mauralva]

Can you help me a little more in the subject of create, connect, and comunicate between TCP Server and TCP Client?. I have two NodeMCU DevKit with ESP-12. One of them its connected to a Arduino MEGA, and the other its connected to a Arduino Uno. Both of them are flashed with ESP-Link-v2.2.3 In the MEGA flash your TCP Server Example uncommenting the lines for de serial debug, and changing the ip of tcpServer and tcpPort In the UNO I flash your TCP Client Example, making the same change like in the other example. The SLIC protocol seems to work fine. The Debug of MEGA give me the fallowing message: 192.168.4.100:7002 is served over connection number # = 0 EL-TCP ready and nothing more. Te Debug of Uno give me the fallowing message: 192.168.4.100:7002 is served over connection number # = 0 EL-TCP ready Sending message to 192.168.4.100:7002 repeating the last message indefinitely By what I see in the code, the message sent is "Message from Arduino Uno WiFi over TCP". But I can´t see that message in any where.

Can you help me what im doing wrong?

[beegee-tokyo]

According to your comment, both ESP have the same IP. That is not possible. Give the server and the client different IP addresses and it should work.

[Mauralva]

First of all: Thanks for the very quick answer

Let me explain better:

The ESP attached to the MEGA is configured as SOFT-AP with DCHP, and IP=192.168.4.1 The ESP attached to the UNO is configured as STA with DHCP, and IP=192.168.4.2

The same ip that you see is the IP from server example.

// IP address for this demo is a local IP. // Replace it with the IP address where you have a TCP socket server running char * const tcpServer PROGMEM = "192.168.4.1"; // Port for this demo is the port used by the TCP socket server. // Replace it with the port that your TCP socket server is listening to uint16_t const tcpPort PROGMEM = 7001;

In the code, that variables are used in the fallowing statment tcpConnNum = tcp.begin(tcpServer, tcpPort, SOCKET_TCP_SERVER, tcpCb); // SOCKET_SERVER ==> accept connections

I understand in that line I'm raising a server with that IP and Port. I'm in right?

I assume that the server TCP is in the AP, and the client is in the STA.

Then, in the client example I wrote the same ip and port of the server. // IP address for this demo is a local IP. // Replace it with the IP address where you have a TCP socket server running char * const tcpServer PROGMEM = "192.168.4.1"; // Port for this demo is the port used by the TCP socket server. // Replace it with the port that your TCP socket server is listening to uint16_t const tcpPort PROGMEM = 7001;

And these variables are used in: tcpConnNum = tcp.begin(tcpServer, tcpPort, SOCKET_TCP_CLIENT_LISTEN, tcpCb); // SOCKET_CLIENT ==> we expect a response

I understand in that line I'm connecting to one server in that IP and Port. I'm in right?

[beegee-tokyo]

You're right, that should work. Misunderstood your first message. Not sure why the server is not receiving the message. But I never tested the code with one ESP as AP and the other one connected to it. I have the server-client connection working with 4 ESP's, one is a client sending commands to the other 3 which are setup as servers. But the whole configuration is connected over my WiFi router/modem, not with one ESP as AP. Can you test using both ESP's connected to an AP (which is none of the two ESP's)?

[Mauralva]

I just tested like you recommend me (both esp conected to a Router. Then, one ESP configured as Server, and the other configured as a Client), but I have the same result.

Another question. If im connected to a network between the router, and i have the two ESP like i comment before, also i conect a PC to the network. Can I connect to the server created in one ESP in the IP 192.168.1.100 with thera term?

[beegee-tokyo]

Beside of IP and port, did you change anything in the example code? I have no idea why it is not working for you.

I don't know Thera Term (Tera Term??). I use PacketSender on Windows to test TCP/UDP servers and clients.

[Mauralva]

Yes, I dont touch any more than the statments that I say before.

Yes, Tera Term is the program. As I can see, Packet Sender allow you to create a Server/Client Socket. But Tera Term only act as client.

I am thinking the problem its in the Mega. I will use another kit next week and i tell you.

Many Thanks!!!

[Mauralva]

Ok. I bought two new MEGA2560 and flash fresh firmware. Also connect the two ESP to a Router, acting both of them like STA. I put Serial1 to Serial, and Serial0 to debug (also try putting Serial0 as Serial and Debug) The Output debug now show this: In the server side:

EL-Client starting!                                            
ELC: got 10 @65C: 2 648 0 D9 2E                                
RESP_V: 1608                                                   
SYNC!                                                          
EL-Client synced!                                              
Waiting for WiFi ELC: got 14 @65C: 3 648 1 1 0 5 0 4A D9       
RESP_CB: 1608 1                                                
WIFI CONNECTED                                                 
ELC: got 10 @65C: 2 2 0 19 32                                  
RESP_V: 2                                                      
.2                                                             

192.168.1.101:12345 is served over connection number # = 13340 
EL-TCP ready 

In the client side:

EL-Client starting!                                            
ELC: got 10 @6F3: 2 6C8 0 B7 3                                 
RESP_V: 1736                                                   
SYNC!                                                          
EL-Client synced!                                              
Waiting for WiFi ELC: got 14 @6F3: 3 6C8 1 1 0 5 0 A8 12       
RESP_CB: 1736 1                                                
WIFI CONNECTED                                                 
ELC: got 10 @6F3: 2 2 0 19 32                                  
RESP_V: 2                                                      
.2                                                             

Conectando a: 192.168.1.101:12345
TCP socket setup failed, try again in 10 seconds after reboot

I think the problem its in booth sides (client and server) becouse i use the Packet Sender to create a server o to send a packet to the server, and neither work. Can you give me a guide to try make this work?

[beegee-tokyo]

Beside of example code that you are using I have nothing I can share with you.

What I saw is that you are using SOCKET_TCP_CLIENT_LISTEN in tcp.begin(). Just for testing change it on the client side.

On the client side try tcpConnNum = tcp.begin(tcpServer, tcpPort, SOCKET_TCP_CLIENT, tcpCb); instead of tcpConnNum = tcp.begin(tcpServer, tcpPort, SOCKET_TCP_CLIENT_LISTEN, tcpCb);

SOCKET_TCP_CLIENT_LISTEN waits for a response from the server after sending a packet before it closes the connection. SOCKET_TCP_CLIENT just sends a packet and closes the connection.

[Mauralva]

@beegee-tokyo finaly y could make it work. I dont know what was realy the problem. But after erase the esp memory with 1M.bin all in FF, and then flash the last Alpha version of esp-link, the API start to work fine.

Now I have another issue. In the API Doc, reference a class named ELClientTcp , but no .cpp or .h files with that names are in the git repo. I think the right class is named ELClientSocket.

Now Im decifrating the code becouse I need to make to do only few things: 2 o 3 modules bringing data to one that its acting as collector. Then, this burst all data collected to a PC when a certain command was received.

Thanks!

[beegee-tokyo]

Good that you got it to work.

Documentation needs to be updated. You are right, ELClientTCP is no longer in the library, it is replaced by ELClientSocket.