The Can't Add Edge Detection For Pin Error Again

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Introduction

The "Can't add edge detection for pin" error is a frustrating issue that many RetroPie users have encountered, especially when trying to set up custom joypads. This error message is often accompanied by a list of pins that are already in use, making it difficult to troubleshoot the problem. In this article, we will delve into the possible causes of this error and explore potential solutions to get your custom joypad up and running.

Understanding the Error Message

The error message "Can't add edge detection for pin" indicates that the GPIOnext software is unable to add edge detection for a specific pin. Edge detection is a feature that allows the software to detect changes in the pin's state, such as when a button is pressed or released. When a pin is already in use, the software cannot add edge detection for that pin, resulting in the error message.

Checking the GPIO Status

To troubleshoot the issue, we need to check the GPIO status of the Raspberry Pi. We can do this by running the command sudo cat /sys/kernel/debug/gpio. This command will display a list of all the GPIO pins on the Raspberry Pi, including their current state and any devices that are using them.

pi@retropie:~ $ sudo cat /sys/kernel/debug/gpio
gpiochip0: GPIOs 512-565, parent: platform/3f200000.gpio, pinctrl-bcm2835:
 gpio-512 (ID_SDA              )
 gpio-513 (ID_SCL              )
 gpio-514 (GPIO2               )
 gpio-515 (GPIO3               )
 gpio-516 (GPIO4               |sdmode              ) in  lo 
 gpio-517 (GPIO5               )
 gpio-518 (GPIO6               )
 gpio-519 (GPIO7               )
 gpio-520 (GPIO8               )
 gpio-521 (GPIO9               )
 gpio-522 (GPIO10              )
 gpio-523 (GPIO11              )
 gpio-524 (GPIO12              )
 gpio-525 (GPIO13              )
 gpio-526 (GPIO14              )
 gpio-527 (GPIO15              )
 gpio-528 (GPIO16              )
 gpio-529 (GPIO17              )
 gpio-530 (GPIO18              )
 gpio-531 (GPIO19              )
 gpio-532 (GPIO20              )
 gpio-533 (GPIO21              )
 gpio-534 (GPIO22              )
 gpio-535 (GPIO23              )
 gpio-536 (GPIO24              )
 gpio-537 (GPIO25              )
 gpio-538 (GPIO26              )
 gpio-539 (GPIO27              )

Setting the Pins

To set the pins for your custom joypad, you can use the gpionext set pins command. This command will set the specified pins as inputs, allowing the software to detect changes in their state.

gpionext set pins 3,5,7,8,10,11,13,15,29,31,32,33

Error Messages

When you run the gpionext set pins command, you may encounter error messages indicating that the pins are already in use. These error messages can be frustrating, but they can also provide valuable information about the issue.

Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 3(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 5(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 7(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 8(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 10(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 11(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 13(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Can't add edge detection for pin 15(pin is already in use). Skipping.
Mar 10 05:11:14 retropie python3[1165]: Pin 29 is not set as input. Skipping.
Mar 10 05:11:14 retropie python3[1165]: Pin 31 is not set as input. Skipping.
Mar 10 05:11:14 retropie python3[1165]: Pin 32 is not set as input. Skipping.
Mar 10 05:11:14 retropie python3[1165]: Pin 33 is not set as input. Skipping.

Troubleshooting

To troubleshoot the issue, we need to identify the cause of the error message. In this case, the error message indicates that the pins are already in use. This could be due to a number of factors, including:

  • Other devices using the pins: It's possible that other devices on the Raspberry Pi are using the pins, preventing the GPIOnext software from accessing them.
  • Incorrect pin settings: If the pin settings are incorrect, the software may not be able to access the pins.
  • Software conflicts: Conflicts between different software packages may be causing the issue.

Solutions

To resolve the issue, we can try the following solutions:

  • Check the GPIO status: Run the sudo cat /sys/kernel/debug/gpio command to check the GPIO status of the Raspberry Pi.
  • Set the pins correctly: Use the gpionext set pins command to set the pins correctly.
  • Disable other devices: Disable any other devices that may be using the pins.
  • Update the software: Update the GPIOnext software to the latest version.
  • Reboot the Raspberry Pi: Reboot the Raspberry Pi to ensure that all changes take effect.

Conclusion

The "Can't add edge detection for pin" error is a frustrating issue that can be caused by a number of factors. By understanding the error message and troubleshooting the issue, we can identify the cause of the problem and resolve it. In this article, we have explored the possible causes of the error and provided solutions to get your custom joypad up and running.

Additional Tips

  • Use the latest software: Make sure to use the latest version of the GPIOnext software.
  • Check the GPIO status regularly: Regularly check the GPIO status of the Raspberry Pi to ensure that the pins are not being used by other devices.
  • Document your setup: Document your setup and configuration to ensure that you can easily troubleshoot any issues that may arise.

Final Thoughts

The "Can't add edge detection for pin" error is a common issue that can be caused by a number of factors. By understanding the error message and troubleshooting the issue, we can identify the cause of the problem and resolve it. With the solutions provided in this article, you should be able to get your custom joypad up and running in no time.

Introduction

In our previous article, we explored the "Can't add edge detection for pin" error and provided solutions to get your custom joypad up and running. However, we understand that some of you may still have questions about this issue. In this Q&A article, we will address some of the most frequently asked questions about the "Can't add edge detection for pin" error.

Q: What causes the "Can't add edge detection for pin" error?

A: The "Can't add edge detection for pin" error is caused by a number of factors, including:

  • Other devices using the pins: It's possible that other devices on the Raspberry Pi are using the pins, preventing the GPIOnext software from accessing them.
  • Incorrect pin settings: If the pin settings are incorrect, the software may not be able to access the pins.
  • Software conflicts: Conflicts between different software packages may be causing the issue.

Q: How can I check if other devices are using the pins?

A: To check if other devices are using the pins, you can run the sudo cat /sys/kernel/debug/gpio command. This command will display a list of all the GPIO pins on the Raspberry Pi, including their current state and any devices that are using them.

Q: How can I set the pins correctly?

A: To set the pins correctly, you can use the gpionext set pins command. This command will set the specified pins as inputs, allowing the software to detect changes in their state.

Q: What if I'm still experiencing issues after trying the solutions?

A: If you're still experiencing issues after trying the solutions, it's possible that there's a conflict between different software packages. In this case, you may need to try a different approach, such as:

  • Disabling other devices: Disable any other devices that may be using the pins.
  • Updating the software: Update the GPIOnext software to the latest version.
  • Rebooting the Raspberry Pi: Reboot the Raspberry Pi to ensure that all changes take effect.

Q: Can I use the GPIOnext software with other devices?

A: Yes, you can use the GPIOnext software with other devices. However, you may need to configure the software to work with the specific device you're using.

Q: Is the GPIOnext software compatible with all Raspberry Pi models?

A: The GPIOnext software is compatible with most Raspberry Pi models. However, it's always a good idea to check the compatibility of the software with your specific device before installing it.

Q: Can I use the GPIOnext software with other operating systems?

A: The GPIOnext software is designed to work with the Raspberry Pi's operating system, which is a variant of Linux. However, it's possible to use the software with other operating systems, such as Windows or macOS, using a virtual machine or a cross-compilation environment.

Q: Where can I find more information about the GPIOnext software?

A: You can find more information about the GPIOnext software on the official website, as well as on online forums and communities dedicated to the Raspberry Pi and GPIO programming.

Q: Can I contribute to the GPIOnext software?

A: Yes, you can contribute to the GPIOnext software by reporting bugs, suggesting new features, or even contributing code to the project. The GPIOnext software is an open-source project, and contributions from the community are always welcome.

Conclusion

The "Can't add edge detection for pin" error is a common issue that can be caused by a number of factors. By understanding the error message and troubleshooting the issue, we can identify the cause of the problem and resolve it. We hope that this Q&A article has provided you with the information you need to get your custom joypad up and running. If you have any further questions or concerns, please don't hesitate to reach out to us.