DFPlayer + Speakers causes a reset of my mega


I'm new to the electronics field and learning a lot. I am having a problem with the DFPlayer resetting as the mega goes through the setup.

My understanding is that this is a power problem. If I unplug the speakers, the program will run fine. I can plug the speakers back in after the setup and it will work as expected. When I attach a meter to the DFPlayer, I can see the jump in current from 0.04 to 0.11 (I'm using the 10A port). The DFPlayer is powered from a regulated 5V rail from a 6 pack of AA batts with a ±7.8V. The rail also powers the mega, a nrf24L01, a couple buttons, 16x2 lcd, a buzzer, and two led's.

Is there a simple fix for this? I'm a total newbie and have tried searching but could not see a solution.

Thanks for your help.

I posted this in the arduino discord channel and got some advice on how to solve this issue. I am going to try adding a large capacitor (1500uf) across the power rail and see if that fixes the issue.

Disclaimer - I've never used the DFplayer.

Are you sure the speaker is wired correctly? It should be a mono speaker wired between SPK1 and SPK2 (no ground connection to the speaker).

I can see the jump in current from 0.04 to 0.11

A current spike with an associated voltage-drop seems like a reasonable explanation. (It would be the voltage drop that causes a reset.) And "big capacitor" might help.

The meter is probably isn't responding fast-enough to show the true current peak (or the true voltage drop). And, with nearly 8V (3V to spare) I wouldn't expect 110mA to drop the voltage enough to cause a problem.

I also wouldn't expect a current spike that's different from the usual current, and I wouldn't expect to measure anything at all (or to get a reset) if you connect the speaker with no sound playing. (With no sound playing there should be no current through the speaker.)

Are all your wires suitable for the current they carry? Many cheap hook-up wires are not suitable for significant current, they are meant for signals only.