Thank you for the response. I'm using the DFPlayer Pro as a standalone player, I'm not connecting it to an ESP32 or an Arduino after I set the AT commands. The voltages are all stable. I ordered a R1 0R resistor to see if I can get the effect I want with a button.

After I connect the DFPlayer Pro to my computer and make the PLAYMODE setting change and confirm the change. I reconnect it to my computer and it has reset.

When I used the AT+SAVE command I don't get an OK response.

I tried adding the \r\n to the end of the command and didn't get the OK response.

I can't find a comprehensive list of the AT commands and the WIKI for the DFPlayer Pro isn't complete. Can you point me to a good resource for them?

Thanks

Ron

Thank you for responding, I'm sure that's my problem.