Questions tagged [tcpip]

This should be used when referring to the transmission protocol TCP/IP.

Filter by
Sorted by
Tagged with
1 vote
2 answers
52 views

SNMP Manager - Multiple IP address -issue

I have multiple SNMP devices on the same network and I am trying to request, via OID numbers, each SNMP device and assign the response into an array. When I request a single IP, I get the correct ...
0 votes
2 answers
29 views

ESP8266 Wemos D1 min pro - how to change TCP_SND_BUF?

Is there any way to change the TCP send buffer size (TCP_SND_BUF) on this module ? Now it is equal to TCP_SND_BUF = 2 * TCP_MSS = 2 * 1460 = 2920. Editing lwipopts.h doesn't make any difference. The ...
2 votes
1 answer
577 views

ESP8266 - How to recieve UDP multicast packet?

how can I recieve udp multicast packets in ESP8266? I have this piece of code: #include <ESP8266WiFi.h> #include <WiFiUdp.h> const char* ssid = "my_wifi_ssid"; const char* ...
1 vote
0 answers
161 views

How to send AT Commands by code using Arduino uno, ESP 8266 01

What I'm trying to achieve ==> Connect to my WIFI hotspot by AT commands via code then connect to my local node server by using REST API. Currently, I am able to send AT commands and receive ...
0 votes
1 answer
279 views

How to access GPS location without internet

I need to provide a basic geolocation service for my clients. I built a location service based on the phone geolocation. It works great, not a problem. My problem is that some of my clients don't have ...
  • 103
2 votes
1 answer
294 views

Is there any way to catch the response of SIM800L after sending the at command?

I am using sim 800l with arduino. I am successfully sending AT command from arduino, not in serial monitor but I am unable to catch the response after each successful command execution if its ok or ...
  • 49
3 votes
0 answers
350 views

ESP32 HTTP Server request interrupts Telnet session

I have an ESP32 application that uses a web server as a user interface. For auditing and debugging during development I use Serial; however, that is impractical in the installed system. So, I decided ...
3 votes
0 answers
1k views

Modbus TCP/IP using Arduino uno and ENC28J60 module

I have this project where I need a modbus tcp server that will host a series of sensor data for other modbus client devices to read. I use this Library by Andresoarmento This is the code i am using ...
2 votes
2 answers
283 views

Static IP for ESP8266 based on gateway

I'm new to Arduino programming. I want to make my ESP8266 get a static IP address based on the gateway's IP address. I mean if the gateway is at 192.168.0.1 then the ESP8266 should get 192.168.0.15 as ...
1 vote
0 answers
83 views

Two SSL connections at the same time on Uno WiFi rev 2

So I want to have one persistent SSL connection to a cloud server (Azure IoT Hub) to upload telemetry and another SSL connection to a server to perform a simple GET request every 30 minutes. I've ...
1 vote
0 answers
2k views

TCP client readStringUntil only when data exists

I have the attached script that reads data from a socket server (it is PHP at the server end). My problem (I think) is that the readStringUntil() needs a test above it, so that it "reads up to \r&...
  • 242
0 votes
1 answer
110 views

I can't run shell commands on Linux through AVR sketch (Arduino Yun)

I'm a little confused with some Process.h methods. I'm trying to run the command "nc 192.168.1.15 9911" to the Linux processor through a sketch. The appropriate netcat listener is waiting on ...
1 vote
0 answers
221 views

Arduino Mega failing to connect to XAMPP database/php server to send HTTP requests

I have developed an application with a SunFounder Mega2560 with a W5100 Ethernet shield that acts as a server and successfully parses TCP message packets from a client sending in updates. I am now ...
1 vote
1 answer
1k views

Multiple WiFi client/server connections

I'm implementing a WiFi HTML web server using the WiFiNINA library, an Adafruit Airlift ESP32 coprocessor, and a Teensy 3.5. It's starting to work, but I have a couple of questions. This simplified ...
1 vote
0 answers
127 views

Problem with multi-client ASCII text parser (TCP)

I have been having a heck of a time getting my Arduino Uno Rev2 application to work as intended, which is to parse commands from multiple clients sending in ASCII-based commands over WiFi in order to ...
1 vote
2 answers
2k views

ESP8266 Webserver not reachable after 2 minutes from reset

I have a Keyes Espressif ESP8266 NodeMCU, I have two LEDs that I want to control which are connected to the ESP. When I open the webpage http://10.0.0.5/5 after uploading the sketch it works fine. If ...
0 votes
1 answer
807 views

creating HTTP persistent connection, to create 'smooth' data over GSM sending

Project goals Send data over GSM to firebase Fast sampling - need to send 16 bytes every half second to firebase Send data using GET or POST to server with PHP script, that redirect data to firebase ...
2 votes
0 answers
213 views

Can't POST data with Arduino and ESP8266

I'm having problems with my Arduino UNO and the ESP8266 module. I need to send values from Arduino to my PHP web page in this way: http://www.server.com/km/db.php?id=53 the ESP8266 module is working ...
1 vote
0 answers
380 views

Arduino Mega with SIM800L running Modbus TCP/IP

I'm trying to set up an Arduino Mega with a SIM800L module and trying to get Modbus TCP running on said Mega. I've set Modbus TCP over wifi and serial before but I used libraries for those. The ...
2 votes
0 answers
74 views

Converting Client input char to int

I'm trying to print out the temperature from a DS18B20 sensor to my app via a tpc connection. Because I have two sensors connected I will need to call the one needed by an Index. This index comes from ...
  • 41
0 votes
1 answer
155 views

Forbidden characters in TCP/IP

I'm trying to send data from my ESP8266 to a NodeJS TCP server, the connection and basic charakters (48-90) are working fine, but if I use others like ASCII-Code (0,1,2,3...) I don't get any usefull ...
  • 25
-1 votes
1 answer
113 views

Esp8266-01 AT Commands returns partially

Im trying to get html response from server via esp01 module when using the serial monitor in arduino studio everything works fine here is the serial monitor output AT+CIPSTART="TCP","aaaa.aaaa",...
  • 99
2 votes
1 answer
1k views

Using c_str() on String for IPAddress with NTPClient provides wrong values

Libraries NTPClient Board Olimex ESP32-POE board Behaviour I have written a code that connects the board to a local NTP Server (which is an embedded board). I tried assigning the IP Address of ...
1 vote
1 answer
1k views

How to configure TinySine 3G module (SIM5320E) for HTTP GET request

I recently bought a 'TinySine 3G shield (SIM5320E) 900/2100Mhz' based on Adafruit_FONA libraries to use with Arduino Mega 2560 R3. It successfully registered with Vodafone AU. Other functionality ...
  • 121
1 vote
0 answers
695 views

Arduino/ESP8266 - TCP server, connect to AP, receive connections/data

We're trying to use an ESP8266/Arduino Uno as a TCP server, which connects to a wireless AP and then receives commands from other devices on the same network. Currently we got the "connect to AP" part ...
-1 votes
1 answer
1k views

Multiple #ifndef vs. single one #endif

My question is connected with the issue as linked: Is there any good working MODBUS TCP master library available for Arduino? An example of Modbus TCP master library as suggested in the post above. A ...
0 votes
1 answer
2k views

ESP8266 check if TCP client disconnected...informally

Hi with ESP8266WiFi library, I usually check for connection of a TCP client with client.connected(). But it seems to still return true if my TCP client in an unexpected way (like disconnect to WiFi/ ...
  • 33
3 votes
0 answers
4k views

How to listen to multiple server ports with ESP8266?

I'm using WeMos D1 R2. I'm trying to listen to both ports 1992 and 1993. This is my current code: #include WiFiServer server_1992(1992); WiFiServer server_1993(1993); void setup() { Serial....
  • 33
0 votes
1 answer
1k views

ESP8266 cannot create TCP connections to this particular server

EDIT: I have created an issue about this here: https://github.com/esp8266/Arduino/issues/4593 I have this server: 185.205.210.197 (Check that it works: http://185.205.210.197/) And I have this code ...
  • 215
0 votes
1 answer
1k views

How to send MFRC522 data to a C# app using a NodeMCU TCP server?

I am trying to send MFRC522 data to a C# application through a NodeMCU acting as an access point for the C# app. I have modified the code I got from this site. #include ESP8266WiFi.h> #include SPI....
1 vote
2 answers
979 views

Communication with socketserver fails after specific number of packets

I'm trying to implement a full-duplex communication between my ESP8266 and a socketserver running on my laptop. In concrete I need each of the devices to initiate communication whenever it needs to. ...
  • 1,771
0 votes
1 answer
2k views

ERROR on SIM900AT comand HTTPDATA (POST method)

Good day community, I have a project which is VEHICLE GPS Tracker and I'm using Arduino Mega, NEO GPS6MV2 and SIM900. I'm using SIM900 to send the GPS coordinates on a web server. I'm using the POST ...
0 votes
1 answer
7k views

ESP8266 send TCP HEX packet with 4 chars

I'm building a remote for my WiFi-RGB Lights. I have an ESP8266, which should send one TCP packet with 4 chars. My code: #include <ESP8266WiFi.h> const char* ssid = "Wifi"; const char* ...
1 vote
1 answer
285 views

Sending JSON message to web api via post. Why does HTTP 1.0 versus 1.1 make a difference?

I am sending a message to a web api call every xx seconds. I could not get it to work at all until I changed the header from HTTP 1.1 which is what I was using to HTTP 1.0. Then, it started working. ...
2 votes
1 answer
254 views

ESP8266 problem with recieved data trasmission via TCP

I am having small project where I want to read couple of analog inputs from Arduino UNO, send it via software serial to ESP8266-01 and from that to python server using TCP. Data is sent to ESP using ...
  • 119
3 votes
1 answer
4k views

Data transmission Serial to TCP

I am trying to send numeric data using ESP8266 to local network python server. Before that I am collecting data from sensors using Arduino UNO and then send it to ESP using hardware serial. ESP8266 ...
  • 119
2 votes
2 answers
10k views

ESP8266 TCP connection WiFiClient issue

I am using ESP8266 01 board to send some data via TCP to server on local network. My code is: #include <ESP8266WiFi.h> const char* ssid = "ssid"; const char* password = "pas"; const char* ...
  • 119
1 vote
0 answers
452 views

How do I send HTTP request using ESP8266 to other port than 80?

I currently have a working connection to my ESP8266 module. However, I can only connect to a server using the port 80, is it possible to choose a different port? I can connect using AT+CIPSTART="TCP"...
  • 215
3 votes
1 answer
11k views

Is there any good working MODBUS TCP master library available for Arduino?

I would like to connect with Fronius solar inverter through MODBUS TCP with Arduino to READ and WRITE register values only. I want to set the Arduino as master and the Inverter as slave. I want to use ...
3 votes
1 answer
9k views

How to run TCP socket server on Arduino Uno WiFi?

2017-03-23 update I still don't know why it works so well on Yún. Maybe it has a better antenna? Anyway, I've returned Uno WiFi and got a SparkFun ESP32 Thing. Unfortunately, it has the same problem ...
0 votes
2 answers
4k views

How to create TCP server on Arduino UNO WiFi?

I'm currently trying to make my Arduino UNO WiFi work as a TCP host, so I can send him a TCP message and it sends a response. I had no problem doing this on the Arduino Galileo Gen 2 using the ...
  • 215
1 vote
2 answers
2k views

ESP8266 ASyncTCP class example

I am new to ESP programming on Arduino, as before I was developing on eLua. There were some memory problems in Lua, so I decided to move to Arduino. After looking at some examples, I found a library ...
  • 11
3 votes
4 answers
6k views

Scan IP address of ESP8266

I am working on a project in which, the mobile app/browser sends HTTP command to ESP8266 in AP mode. The default IP address of ESP is 192.168.4.1. Therefore in order to connect the ESP to WiFi, the ...
  • 450
5 votes
2 answers
25k views

Multiple client server over wifi

Trying to setup a server on Arduino to support multiple clients, I am able to support one but I don't want to flush that client to make another connection. #include <ESP8266WiFi.h> const char* ...
2 votes
1 answer
712 views

Is it possible to print client IP or MAC address from Arduino WiFi web server?

For a school project I want to make a little project with the Arduino Uno. I want to make a project that does something when a client connects to the WiFi shield. My first thought was to print out ...
0 votes
3 answers
1k views

How avoid TCP packet fragmentation?

I'm using an Arduino Uno with an Ethernet Shield and the arduino.cc Ethernet library for a custom TCP-based message-exchanging chat-like protocol. Specifically I'm using the Client class with its ...
  • 101
1 vote
1 answer
2k views

Can't connect to my Arduino via W5100 Ethernet shield

I recently bought a W5100 Ethernet shield and I'm trying to run this simple example, which is a little improvement of the basic WebServer sketch provided by Arduino.cc #include <SPI.h> #include ...
  • 233
0 votes
1 answer
962 views

SIM900 TCP Connection issue

I am having a strange issue where if I try and create a TCP connection to my service, it doesn't work. But any other website, such as google, works fine. The serial monitor output is also slightly ...
  • 163
0 votes
1 answer
4k views

Modbus RTU over TCPip

I have developed my arduino code using below library. I tested code working fine over modbus RTU slave. Now i am planning to use RS485 to wifi instead of wire connection. In order to get data over web ...
  • 447
1 vote
1 answer
870 views

ESP2866 and java ServerSocket

So I have an application that runs on the Arduino that passes info over serial. I'm using a ESP2866 to make it wireless. Arduino->Serial->Esp2866->SocketConn->JavaSocket->Console I ...