Audible noise playing over wav file

dcmrobin

Member
So at this stage of my project I have everything on a breadboard connected with jumpers. All the buttons each have one of their terminals going to the ground rail which is connected to one of the teensy 4.1's ground pins, and the other terminal is connected directly to one of the teensy's pins. then I have the oled display all directly connected to the teensy, (using up another ground pin) and lastly I have the audio board rev D connected directly to the teensy, using up the last ground pin. (again, all connected via jumpers) now, I used to have the audio board's ground going to the ground rail on the breadboard, but it had a lot of noise there so I now have it directly connected to the teensy. This has reduced a lot of the noise, but there's still a fair amount of white noise blaring over the wav file that is playing. Could this be because of all the jumper wires being in close proximity to each other? (the breadboard looks a bit like a mess of wires) The final project is all going to be soldered onto a perfboard and everything is going to be connected using single core 1/06mm wire, which is much better than jumper wire, right? I know the best decision would be to have the audio board directly soldered onto the teensy board itself, but when I got the audio board I was way too eager and immediately soldered some headers onto it. Now if I must, I shall go through the process of desoldering all these headers... but I'm sure you can see why I want to find an alternative, eheh. Any help would be much appreciated!
 
Update: So I discovered that I didn't have the 3v pin on the audio board connected to anything. If soldered to the teensy, it would go to this 3v pin on the teensy: (circled in picture)
1743591125320.png

So I directly connected it to that pin. The result was that the music playing sounded like a beeping mess of random pitches. I also tried connecting the 5v on the audio board to the teensy's 5v, but that changed nothing. When I disconnected the 3v, (the only power pin that was connected to anything) the music returned back to pretty clear in the right ear of the headphones and white noise in the left. So me, thinking it had something to do with my different components like the buttons and screens, removed the audio board and connected it separately to a different teensy that had the same script on it. (no breadboard involved) The exact same result. So then I tried just connected every single pin on the audio board to where it would go on the teensy 4.1 via jumpers, and got the exact result of a beeping mess. Until I disconnected that one 3v pin. Then I would reboot the teensy and it would work- music in the right ear, noise in the left. While that music was playing, I would just begin to connect the jumper cable that was connected to the audio board's 3v pin, again... and instantly got a beeping mess again. I would have to disconnect that 3v pin and reboot the teensy in order to get the music and noise state. Anyone know what is going on here?? The audio board is meant to literally be mounted onto the teensy, so every pin of it should be connected... even that 3v pin. Just in case, I've uploaded a picture of the audio board's 3v pin I've been talking about:
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What is with this one particular 3v pin?!
 
Yes that is correct its meant to be wired point-to-point. The fact you ran it for a while on phantom power may have caused damage. If you look at the schematic for the Audio adapter: https://www.pjrc.com/store/teensy3_audio.html you'll see it only uses the 3.3V rail. If that wasn't connected it would have been stealing power through the protection diodes on the Teensy, likely overloading one or more pins.

You need to establish if you've damaged any of the T4.1's pins using some test code that toggles them perhaps?
 
Yes that is correct its meant to be wired point-to-point. The fact you ran it for a while on phantom power may have caused damage. If you look at the schematic for the Audio adapter: https://www.pjrc.com/store/teensy3_audio.html you'll see it only uses the 3.3V rail. If that wasn't connected it would have been stealing power through the protection diodes on the Teensy, likely overloading one or more pins.

You need to establish if you've damaged any of the T4.1's pins using some test code that toggles them perhaps?
Hey, thanks for the reply... Yeah, I think I may have damaged it. Can you guide me in the right direction as to what code to use to test if it is broken?
 
Write a loop that toggles all the pins slowly enough to check with a multimeter perhaps? Maybe someone already has something like this.
 
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