So, First, I know I have not posted a lot of code, but in this case ... hear me out
I am in the process of programming a relatively bigger project, and while working on one of the modules (FFT with LED display) from the audio library I found it weird that I always have a lot of noise on the default adc1 input (A2) Noise that was specifically according to the FFT above 5kHz and below 100Hz.
I ran many, many tests including isolating the power supply from the LED's driving them from the 3.3V or from the 5V or from external battery or from USB, nothing seemed to make any difference. finally I started to dig into the code and thought: Hmm,, I wonder if different audio inputs behave differently... I switched the analog adc to A( and lo and behold, the noise is gone. the only differences are the audio in in the software and then of course the wire on the breadboard.
And yes, before you ask, the noise was substantial.
Does that make any sense? And if so why?
And if somebody wants to dig through 200 lines of code, I'll be happy to post. since precisely the same code works as expected on A9, I don't believe this is in the code.
I am in the process of programming a relatively bigger project, and while working on one of the modules (FFT with LED display) from the audio library I found it weird that I always have a lot of noise on the default adc1 input (A2) Noise that was specifically according to the FFT above 5kHz and below 100Hz.
I ran many, many tests including isolating the power supply from the LED's driving them from the 3.3V or from the 5V or from external battery or from USB, nothing seemed to make any difference. finally I started to dig into the code and thought: Hmm,, I wonder if different audio inputs behave differently... I switched the analog adc to A( and lo and behold, the noise is gone. the only differences are the audio in in the software and then of course the wire on the breadboard.
And yes, before you ask, the noise was substantial.
Does that make any sense? And if so why?
And if somebody wants to dig through 200 lines of code, I'll be happy to post. since precisely the same code works as expected on A9, I don't believe this is in the code.