[SOLVED] Powering Nano and DFPlayer Mini with batteries or any power from 5v

Other Hardware Motors, Mechanics, Power and CNC
1

Hi,

I'm working with a Nano (chinese clone), and a DFPlayer Mini.

I've got it working fine using usb power.

But I need to power the arduino and the miniplayer via batteries.

No matter what I do, if I use external power, I can't get it to work.

To even get the player to turn on, I need to put 5.7v in (the max an open frame 5v supply I have will supply). Then the player lights up, but doesn't work.

Anything less and the player doesn't even light up.

I've tried various batteries (3x 1.5v aaa, 4x1.5 etc, 2 x cr2032's, 1 x 18650 etc). Arduino turns on, but no light on the DFPlayer Mini.

I am putting power in to the arduino via 5v and gnd, and taking power out to the player from the same pins.

I need to use small batteries because it's for a small device. I'll be putting it to sleep most of the time, and also doing the usual hacks when ready to package (it's a one-off gift) - ie, taking power LED off, cutting out regulator etc. I don't want to use VIN as I want to keep the power/batteries as low as possible to run this. It is doing nothing most of the time, except for listening for a button press then waking up and playing something on the miniplayer, then going to sleep again after a while if nothing else is pressed.

Am I doing something wrong?

Once I can actually get it powered externally then I can perhaps get some advice on the best batteries, but at the moment, no external power is working, only USB!

The only other connections are RX,TX from arduino (10,11) - both with 1k resistors - to TX,RX on the player, GND from arduino to GND on player, 5v from arduino to vcc on player, then spk1 and spk2 from player to single small speakers (tried a few, one I'll be using is from a toy and I can't tell what it is, but tiny, but one I do know is 8 ohm, 0.5w).

Thanks

ps. originally asked a similar question but with more questions in the Audio section but thought this section may be more relevant so will put a link from there to here.

2

Just back from local shop with a 3.7v li-po (I have one hacked out of an old device but ...), a booster and a charger. More expensive than Amazon, but got it today and more importantly, helps them survive after 3 months of lockdown. Will test later...

3

Ok, this all works.

I have another problem now which I read over the last couple of days somewhere where the DF Miniplayer doesn't hear the serial signal so doesn't turn on (at least, the LED doesn't come on and no music plays).

This even happens if I power it via USB from the computer - it works. Then power it via the li-po, the arduino works, but the DF Miniplayer doesn't play. Then if I go back to the USB from the computer it doesn't play.

What makes it play in both cases, is grounding the next/prev pins on the DF player. Then it springs to life. So there's some issue with the serial signal.

I'll have to search and hope I can find it and hope that whoever had the problem fixed it!

4

Hi.

You might want to read this thread.
It is somewhat lengthy with its 99 pages, but you've got the time thanks to lockdown.
That thread is about building lightsabers, and has a lot in common with your project.

5

MAS3:
Hi.

You might want to read this thread.
It is somewhat lengthy with its 99 pages, but you've got the time thanks to lockdown.
That thread is about building lightsabers, and has a lot in common with your project.

Thanks. I'll have a read but I am up against the clock. I need to finish this and ship it abroad in the next day or two most (although I am becoming resigned to it being a late gift, but that's not good at all considering who it is for :frowning: )

6

MAS3:
Hi.

You might want to read this thread.
It is somewhat lengthy with its 99 pages, but you've got the time thanks to lockdown.
That thread is about building lightsabers, and has a lot in common with your project.

Sorry, got 17 pages in so far... Is this to help with the DF Miniplayer problem where the serial communication stops or just about batteries in general? I think I have the battery issue sorted, but there's a problem with the serial communication to the player. At this rate it will take all day to read that thread and if it's not relevant I've lost a day I can't afford to lose. Thanks.

7

I don't know if this will solve the problem you've got.
I did read parts of that thread (which was already large when i found it), because i think it is an interesting thread.
But i didn't learn it off by head, and i'm not doing anything close to building a saber myself so i can't tell it will bring you your solution.

It still has a lot in common with your project (IMHO), and there's a lot of problems and catches covered in there so that's why i pointed you there.

8

Ok, thanks.

My sticking point at the moment is that when powered by a battery, the DFPlayer Mini (I keep calling it a DF Miniplayer?) doesn't work. But if I press the reset button on the arduino, it does work!

I've got an atmega328p today (plus crystal/caps etc) so I may move the project to that so save having to hack bits off the nano to reduce power consumption (only thinking in terms of time not cost!)

So might give that a try first and see if the same problem occurs but if not, need to find out why a reset makes it work but plugging in the power alone doesn't.

9

Actually, this is nuts.

Firstly, I got a bit confused in my last message. I've been with my daughter all day (child) and brain is frazzled. I was only trying it via the battery with the power over USB. It still had that odd problem though of needing a reset, but then I tried it with the PC USB and the same...

Adding a 1 second delay before opening the serial to the DFPlayer Mini, and it works on USB via battery or PC...

AND it now works on the battery!

Ok, well, it seems my final DFPlayer related and power problem is solved - thank you!

Now to get on with the rest of the project!

10

Thumbs up for sharing the solution you found for your problem.

11

MAS3:
Thumbs up for sharing the solution you found for your problem.

Thanks but nothing more annoying than searching for a solution, finding someone else having it and them not posting what it was! :wink: