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Adafruit Music Maker MP3 Shield
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Adafruit Music Maker MP3 Shield

by Zlshep on Wed Aug 04, 2021 12:06 pm

Hi all. I have been using an Arduino Uno with the MPS Music Maker shield, and everything has been fine. But I have just purchased an Arduino Mega and when the sounds play with the music board, the sound quality is distorted - the audio is crackly and poor. Is this a known issue? I am using the basic default Simple Player example library. I am using it the same on both boards. Same speakers, same SD card, both powered via PC USB. But on the Mega it sounds really poor. Can you offer some advice? I am using the ISCP port on both boards; I have disabled the #11 #12 and #13 connectors. It works fine on the Uno. I've got the version with the built-in amplifier and I have not shorted any of the =dB options on the shield so it is basic +6dB output provided by the board itself.

EDIT: Also I have tried lowering the volume in IDE (higher numbers mean lower volume I know)

Zlshep
 
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Re: Adafruit Music Maker MP3 Shield

by Robert_AA on Wed Aug 04, 2021 12:52 pm

Zishep,
I have been using the MP3 Shield on Arduino Mega boards and have not had any issues with distorted sound. I have two of the shields, both with the amplifier. On one I have both the 6dB and 12dB shorted and it is successfully driving a pair of speakers. The second shield I am only using with ear buds at the moment and neither of the dB jumpers have been closed. Again, no issue with distorted sound.

The problem I have been having is that I have never been able to get the software volume control to work. Has that worked for you?

Robert_AA
 
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Re: Adafruit Music Maker MP3 Shield

by Zlshep on Wed Aug 04, 2021 6:33 pm

Robert_AA wrote:The problem I have been having is that I have never been able to get the software volume control to work. Has that worked for you?


Yes, the default is 20. Higher is quieter, so 40 is quieter and 0 is higher (although it sounds no different to the 20). I think that 20 is the maximum you can go down to, it doesn't seem to get any louder for me.

Interestingly the sound is much louder at the default level on the Mega than the Uno for me, I wonder if part of the problem is the amplification? Perhaps the Mega doesn't need it? Unsure.

Zlshep
 
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Re: Adafruit Music Maker MP3 Shield

by Robert_AA on Wed Aug 04, 2021 6:55 pm

I have written a program to change the volume parameter from 0 to 240 in steps of 10 and heard no difference in sound when I produce a test tone at each volume. I have also not heard a difference in playing MP3 files. If others find that the software volume change does work it is probably something stupid that I am doing.

I don't see why the shield should be louder on the Mega than on a Uno. Too much amplitude could cause distortion. In terms of distortion I would check all of my connections, but that is probably something you have already done.

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Re: Adafruit Music Maker MP3 Shield

by adafruit_support_mike on Sat Aug 07, 2021 11:30 pm

@Zishep: post a photo showing your hardware and connections and we'll take a look. 800x600 images usually work best.

@Robert_AA: What are you using as a power supply? A 2W speaker can use up to 750mA, and 'can't get the volume to increase' is often a sign that you're already using all the available current.

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Please be positive and constructive with your questions and comments.