Скачать или смотреть How to Connect to localhost with Arduino via Ethernet Shield

Discover how to successfully connect your Arduino to a local server using an Ethernet Shield. Troubleshoot connection issues and learn best practices for a seamless integration.
---
This video is based on the question https://stackoverflow.com/q/65073414/ asked by the user 'Vetedde' ( https://stackoverflow.com/u/9753359/ ) and on the answer https://stackoverflow.com/a/68619752/ provided by the user 'Vetedde' ( https://stackoverflow.com/u/9753359/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to connect to loaclhost with Arduino via ethernet shield?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Connect to localhost with Arduino via Ethernet Shield: A Comprehensive Guide

Connecting an Arduino to a local server via an Ethernet Shield can be a straightforward process, but it's not uncommon to encounter hurdles along the way, such as connection failures. If you're trying to send data from your Arduino to a server hosted on your computer, but you're facing connectivity issues, you've come to the right place. In this post, we'll walk you through the necessary steps to ensure successful communication between your Arduino and the server on your computer.

Understanding the Scenario

Imagine this setup:

Computer: Connected to Wi-Fi, hosting the server.

Arduino Uno: Wired via an Ethernet Shield to your router.

You want to send data from the Arduino to the server running on your computer. However, despite configuring the Arduino's IP settings and updating the server address, you're still facing "connection failure." Let's explore how you can troubleshoot and resolve this issue.

Step-by-Step Solutions

1. Ensure Proper Setup of IP Addresses

First and foremost, ensure that the IP addresses you are using are correctly configured. Here’s a breakdown:

Server IP Address: Use the correct local IP address of your computer (found using ipconfig on Windows).

Arduino IP Address: Make sure the IP address assigned to your Arduino does not conflict with other devices on the network. It should be on the same subnet as your server's IP address.

2. Check the Ethernet Connection

Confirm that the Ethernet cables are securely connected. Here are a few things to check:

Is the Ethernet Shield properly mounted on the Arduino?

Is the Ethernet cable functional? You might want to test it by connecting another device to the same port.

3. Configure the Arduino Code Correctly

Let’s review the key parts of the Arduino sketch. Ensure the following sections are properly configured:

[[See Video to Reveal this Text or Code Snippet]]

Make sure IPAddress server() correctly reflects your computer’s IP address, and IPAddress ip() provides a unique static IP for the Arduino.

4. Adjust Firewall Settings

A frequent cause of connection failures is the firewall settings on your computer. If your firewall is blocking incoming connections, your Arduino won't be able to connect. Here’s how to check this:

Windows Firewall: Temporarily disable the Windows Firewall to see if the Arduino can connect.

Go to Control Panel > System and Security > Windows Firewall > Turn Windows Firewall on or off.

Turn off the firewall for both private and public networks.

If this resolves your issue, consider adding exceptions for your server application instead of leaving the firewall off entirely.

5. Test Your Server

Ensure that the server on your computer is running and listening on the correct port (in this example, port 3000). You can do this by:

Running a local server program or using a simple tool like netcat to listen on that port.

Testing the server's accessibility from your web browser by navigating to http://localhost:3000.

6. Monitor and Debug

If the connection still fails, utilize the serial monitor in the Arduino IDE to debug. Here’s what to look for:

Are there any error messages printed out?

Does “connecting…” appear before you receive a “connection failed” message? This can help pinpoint where the issue lies.

Conclusion

Connecting your Arduino to a local server can open the door to a multitude of fun and advanced projects, but it requires a bit of setup and troubleshooting. By ensuring correct IP configurations, checking connections, adjusting firewall settings, and using the serial monitor for debugging, you can successfully establish this connecti