I'm doing a little synth with a Nano and some other stuff (filter & fuzz)
When I connect it by USB it works fine and produces sound, but when I connect 9v (also tried 12v) on the Vin pin, it works but the output is faint and there is a lot of noise.
I must say that I'm probing the output after the Nano, before getting to the filter and fuzz.
The strange thing is that when I touch the USB input of the Nano with the outside of the mini USB plug that is connected to the PC it works fine, without reseting or anything, just by those two touching the noise dissapears, removing it noise comes back.
When powered through Vin, you are using the on-board regulator. When powered through USB, you are not.
So you may either be exceeding the current rating for the on-board regulator, or enough current is flowing that it is causing it to go into thermal shutdown.
but when I connect 9v (also tried 12v) on the Vin pin, it works but the output is faint and there is a lot of noise.
If the regulator went to thermal shutdown, it would be off for a while.
But if there was not a common ground, it cold produce such symptoms.
Where's the OP. Maby they have a hopping weekend, and left us till Monday. LOL
How about your common grounds. Is the grounds connected when using battery, or just when using USB ?
I don't use a battery, I'm using a 200mA 9V power supply, I just connected GND to ground but I think I also tried connecting it to GND1 also.
The 5V coming through USB is filtered. Though the 9V should not be noisy enough to create what you are describing.
You can try adding 0.1uF and/or 4.7uF caps between Pos and Neg close to the battery.
This also applies to a power supply?
If the regulator went to thermal shutdown, it would be off for a while.
But if there was not a common ground, it cold produce such symptoms.
Where's the OP. Maby they have a hopping weekend, and left us till Monday. LOL
why a thermal shutdown? It's not that the Nano goes off, it just produces a noise audio output. Also tried a blink program and it works fine with the power supply only.
Could it be that is a noise power supply? Is there a way to reduce that? Maybe with a capacitor as said above?
I'm sorry, I haven't been in the PC all this time to answer!!! XD
Grumpy_Mike:
The strange thing is that when I touch the USB input of the Nano with the outside of the mini USB plug that is connected to the PC it works fine
That means you haven't got a common ground between your arduino and your audio circuits.
No no, everything has common ground! Im using only the one on the power supply, also I'm probing on the audio output of the schematic (on the right)
Ok, this is becoming a mystery. Come on guys.
What could this be?
With a volt meter, check from arduino ground, to the other grounds. Should be close to zero. A loose wire on the breadboard could cause problems. Check while audio is running weird.
Pancra85:
why a thermal shutdown? It's not that the Nano goes off, it just produces a noise audio output.
The output being faint could be due to the regulator shutting down.
The noise you are hearing is most definitely coming from the supply. Sounds like it isn't well regulated, or at least, not as well as your USB's supply.
I misunderstood your initial description. I thought "noise" meant output, not actual unwanted noise.
No no, everything has common ground! Im using only the one on the power supply, also I'm probing on the audio output of the schematic (on the right)
Check that the wiring is actually making contact. What you describe is classic no common ground.
Sorry but there you are.
Maybe a photo of your setup?
What an idiot... I forgot to ground the audio output
For some reason when using USB power the audio doesn't needs a ground (when connected to the same PC I suppose)
I am glad you have it solved. If you go back to your first post, and modify it , change the title adding (SOLVED), others may be able to learn from this thread. Thanks.