Скачать или смотреть Solve the Raspberry Pi and Arduino Serial Communication Crash

Discover how to fix the issue with your Python script crashing when sending data over serial on Raspberry Pi. Learn to leverage absolute paths to ensure a smooth workflow.
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Solving the Raspberry Pi and Arduino Serial Communication Crash

When working on projects involving Raspberry Pi and Arduino, developers often encounter issues that can be challenging to troubleshoot, especially when running scripts in different environments. One common problem arises when a Python script that reads from a text file and sends data over serial encounters a crash when initiated from the system before the Raspbian GUI starts. In this guide, we will break down this problem and provide a clear solution.

The Problem

You have a Python script that successfully reads a text file containing only numbers and sends this data over serial. However, you notice that when this script is executed at startup via the system (before the GUI loads), it crashes. Conversely, the script works perfectly when run in the Raspbian GUI or through an IDE like PyCharm. Since the script is crucial to your project deadlines, you need an efficient way to address this issue.

Key Observations:

The script only crashes when run during the system startup phase.

It relies on a text file (testprog.txt) to retrieve the data to send over serial.

The script uses PyQt5 for the GUI application.

Understanding the Root Cause

The main reason you're experiencing this crash could be related to the relative path you're using to reference the text file. When scripts run in different environments (like the terminal vs GUI), the current working directory may vary, causing issues when trying to locate files.

Relative vs Absolute Paths:

Relative Path: Assumes a default directory that may not be consistent across various execution environments, causing file not found errors.

Absolute Path: Defines the complete path to a file, making it less dependent on the current working directory.

To illustrate, here's the segment of your code that's likely causing the issue:

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

The Solution

By switching from a relative path to an absolute path, you can provide the script with a consistent reference to your text file regardless of how or where it’s executed. Here’s how you can modify your code:

Identify the Absolute Path: Determine the exact path where your testprog.txt file is stored on the Raspberry Pi.

Update Your Code: Replace the relative path in your script with the absolute path.

Updated Code Example

Replace the problematic line with the following:

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

Benefits of This Change:

Ensures consistent file access across different execution environments.

Minimizes the risk of crashes due to file not found errors.

Enhances overall reliability of your script.

Conclusion

In summary, addressing the issue of your Python script crashing when sending data over serial on Raspberry Pi involves changing the file path from relative to absolute. This simple adjustment can save you hours of troubleshooting and help meet your project deadline. Always remember to check your paths when working with file operations in different execution contexts. Happy coding!