DFPlayer Pro Playmode Resets

It sounds like you're experiencing a configuration issue with the DFPlayer Pro module resetting its play mode setting when disconnected from your computer and connected to your breadboard setup. Here are a few steps and considerations to help you resolve this:

### Understanding the Issue

The DFPlayer Pro module uses AT commands to configure its behavior. The AT+PLAYMODE command is used to set the playback mode, where:
- **0**: Repeat mode (default)
- **1**: Folder repeat mode
- **2**: Single repeat mode
- **3**: Random mode

You mentioned that when you set AT+PLAYMODE=3 while connected to your computer, it correctly responds with mode 3. However, when you disconnect it and connect it to your breadboard setup, it resets to mode 2.

### Possible Causes and Solutions

1. **Power Supply Issues**:
  - Ensure that your breadboard setup provides a stable power supply to the DFPlayer Pro module. Inconsistent power can sometimes cause modules to reset or behave unpredictably. Use a regulated 5V power supply if possible, and avoid powering the module directly from the ESP32's 3.3V pin, as it may not supply sufficient current.

2. **Initialization Sequence**:  https://www.heisener.com/
  - DFPlayer Pro modules can have specific initialization requirements. Make sure you're initializing the module correctly when it powers up. This includes setting the correct baud rate (typically 9600 by default), and possibly sending initialization commands (like setting the volume, EQ mode, etc.) after powering it up.

3. **Serial Communication Stability**:
  - Check the serial communication lines (TX and RX) between your ESP32 and the DFPlayer Pro module. Ensure there are no loose connections or interference that could disrupt communication. Use capacitors to stabilize the power supply if necessary.

4. **Check for Interference**:
  - Sometimes, other components on the breadboard (especially motors, relays, or other high-current devices) can introduce noise or voltage spikes that affect the DFPlayer Pro module. Try isolating the module from other components or using separate power lines if feasible.

5. **Verify Commands and Responses**:
  - Double-check your code to ensure that after setting AT+PLAYMODE=3, it's not inadvertently being reset to 2 due to subsequent commands or incorrect initialization routines. Verify each command sent to the module and the response received to ensure consistency.

### Troubleshooting Steps

- **Power Supply Check**: Measure the voltage supplied to the DFPlayer Pro module on the breadboard. Ensure it remains stable and within the module's operating range (usually 3.2V - 5V).
 
- **Serial Communication Debugging**: Use serial debugging to print out responses from the DFPlayer Pro module during initialization and command execution phases. This will help you track any unexpected resets or changes in settings.

- **Isolation Testing**: Simplify your breadboard setup by removing other components temporarily to see if the issue persists. This can help identify if interference from other components is causing the problem.

- **Module Reset Considerations**: If the module seems to reset only during specific actions (like changing play modes), consider implementing delays between commands to ensure each command is processed correctly before sending the next one.

By systematically checking these aspects, you should be able to identify why your DFPlayer Pro module resets its play mode setting when transitioning from computer to breadboard setup, and implement the necessary fixes to maintain your desired configuration.

After setting the play mode (AT+PLAYMODE=3), you need to save the settings using the AT+SAVE command. This command ensures that the changes are written to the module's non-volatile memory, so they persist even after power cycles.

Here's how you can do it: