Dfplayer mini reset when speaker connected

I use the module DFPlayer mini with an arduino pro mini 3.3V.
DFPlayer works fin when i use DAC_L/DAC_R pins. But when i connect a speaker to SPK1/SPK2 it doesn't work. I listen a huge noise and my arduino reset at the line myDFPlayer.begin(mySoftwareSerial).

I don't know why.

How are you powering it? Maybe the power supply isn't "holding up"?

I try with batery 2xAA and the ttl connecter To the pc

I also try with a buzzer but it did the same sing

Nobody have a clue ?

No not without you supplying more information.
Does it work when the speaker is connected in power up?
Has it ever worked?

no it never work. I listen a very low music when i connect to DAC_R and ground.
i connect like this:

If i connect to SPK_1 and SPK_2 after the init phase (myDFPlayer.begin(mySoftwareSerial)) it works. But it dosent' work when the speaker is connect during the init phase.

I can’t make sense of that reply, first you say it never has worked and then you say it works.
You should not be connecting up a circuit that is powered up anyway.

I got this man , the problems is that DFplayer use YX5200 chip that doesnt like 3.3V.
It runs at 5V , so I guess that you have power it with 3.3V , ( which is a miracle that it work )

I am assuming that you are using a boost circuit to get the 5V , in that case , it is likely that when reset , DFPlayer use hugh power to "test" the speaker , that power is so large that it cause the boost to use more of the 3.3V line and the Arduino voltage will drop to about 2V at a time , that cause reset .

I didnt find the solution yet , but adding a large cap , mine is 3300uF , in the DFPlayer power rail will make it work .

I had a similar issue today, after hours of testing to figure out the reason, curlyz has saved my day. It was indeed a power issue (dropping voltage) which caused the arduino to reset.
I was using a LiPo 3.7v wired to a tp4056 (charger module) which itself powered a 5v booster which powered the arduino, the dfPlayer and a touchscreen. In my case the lipo charger module (tp4056) was acting wierd and dropping voltage dramaticly so that the bosster couldnt adjust and boost fast enough. All of that caused voltage drop (when playing audio and more current is needed).
grapped a new lipo charger then problem solved! (still have few mV drop but the arduino is not resetting anymore)