I am creating a small product for friends and I would like it to be at a polished level. Everything is working but when i power on the circuitry it makes a noticable pop sound. I tried using a 2n7000 on the speaker ground but I think I programmed it incorrectly as it didn't do anything and the sound quality was badly affected. What I would like is for the speaker to connect to the mp3 module after powering on to avoid the pop from the power surge. Is there something small I could use. I am considering using a relay but the standard one that came with my arduino package is too big for my enclosure size. Is there something smaller maybe? Would that work?
If your mp3 player has a "mute" connection, use that until the power has been applied for a second.
Are you using the SPK_1 & SPK_2 pins of the module? If so, neither of them are ground. If you use a transistor or any other component to connect one of them to actual ground (GND), that won't work and might damage the player.
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I see, so would a small ns8002 or pam8403 amp do that? Looking at the pam8403 datasheet it has a mute pin but majority of the modules sold dont have it on the pcb. Would I be able to solder a wire directly to the pin and use the nano to write high or low to control the muting?
The DFPlayer mini module that's being sold by DigiKey has a 0 ohm resistor that you can move to enable the mute function. Some of the knocks off do as well; a read through the first message in the topic below might be enlightening.
The typical circuit for the pam8403 shows the mute pin is active -low-, to if it is connected to an Arduino in, and the grounds are connected, setting the pin low will mute and setting the pin high will enable the amp.
Ive had a look and it seems promising but my chip is the old JL ones which arent listed on the post so I am hesitant to solder the resistor since I dont have a spare so I dont want to break this one. Has someone done something similar with the older JL chip versions
Ive gone ahead and bought a ns8002 mono amp module due to their extremely small form factor and the mute pin is easy to access. Hopefully this will solve my issue
Hey Paul, ive bought a pam8302a and I am using a 2n700 to keep it grounded as the arduino boots up removing popping sounds as the dfrobot mp3 is being initialized, I am still getting an initial power pop since it takes a few milliseconds to digitalwrite to the transistor to go to HIGH (muting the pam). Is there anything else I can do to remove the initial pop. I looked at a depletion mosfet to keep the ground open until it is pinched by the mosfet but it seems too complicated for my use (negative voltages etc).
Do I understand that the "pop" is generated by the mp3 and is not there is the mp3 is not connected?
Have you verified the audio file does not have the "pop?" ( I like audacity )
What if you hold IO_1 pin LOW until after you start playing the audio?
The issue is as soon as power is applied to the circuit the speaker pops. This is before the mp3 module is playing anything. The mp3 file is not the issue
The pop is generated by the pam8302 as soon as power is applied, then the Arduino mutes it and the subsequent pops from initialisation of the mp3 module are successfully muted. I want something to bring the SD mute pin low as soon as it’s on instead of relying on the Arduino to bring it low as the code isn’t instantly executed
You can delay the power to the amplifier a bit by inserting a small resistor, 1-10 Ohms followed by a large electrolytic capacitor in the + power to the amplifier. Vary the resistor until the delay in power application lets the mute be effective.
Sounds exactly what I’m looking for! What capacitor would you recommend and would a 1k trimpot allow for adjustable delay? Could you create a diagram or refer me to one to see how I wire it up many thanks
Late seeing the thread, but I see no code or schematic in the couple of weeks since it started? Is it possible that initialisation of the DFR Player itself could be a factor?
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