popping noise at startup

Knallberto

Hi,

I am using PD with Bela to create different simple instruments for a school project. I have the following problem: Whenever I turn on the board, there's a loud popping noise that comes through the audio outputs. I've tried a few things to minimize it, like adding a 4-second delay at the beginning of my Pure Data patch (before I turn up the output volume), but it's still there. I'm wondering if there's a software-based solution to this issue? Or is there something else I can do to prevent the popping noise from occurring?

Thanks for any help or advice.

Best regards
Andy

giuliomoro

Updating your board's code to the latest dev branch may reduce it

https://learn.bela.io/using-bela/bela-techniques/updating-bela/

Knallberto

Thanks for the advice. I updated, but the startup sound is still the same.

giuliomoro

Did you rebuild your project after the update?

What does the following command return when you run it in the console at the bottom of the IDE?

grep Mcasp::startAhclkx /root/Bela/core/I2c_Codec.cpp

Knallberto

Yes, I did. When I run the command in the console, I do not get a return. The console only writes "root@bela ~/Bela# grep Mcasp::startAhclkx /root/Bela/core/I2c_Codec.cpp".

giuliomoro

right that means you don't actually have the latest code, as that should return:

grep Mcasp::startAhclkx /root/Bela/core/I2c_Codec.cpp
	Mcasp::startAhclkx();

maybe you did not update using a zip archive of the dev branch?

Knallberto

I downloaded the latest version following your link and then updated in the IDE. So I guess it is not the latest dev branch? I will try again next week and get back to you. I have the Bela in a school right now so I cannot access it.

giuliomoro

oh right, sorry I didn't point to the last section of the linked page: "updating to an experimental release" https://learn.bela.io/using-bela/bela-techniques/updating-bela/#updating-to-an-experimental-release

Knallberto

okay, now I installed the dev branch and it returns:
Initialise...
Mcasp::startAhclkx();
/root/Bela

But the startup popping noise is still there.

giuliomoro

It should be significantly quieter with this branch. Did you rebuild the project that is running first at boot?

Knallberto

yes I did, but I could not hear much difference, thanks anyway