electr0dave
Junior Member level 1
Hello everyone.
I made a small circuit to be able to test some experience with signal processing.
Basimente I do input audio (with its analog circuit) using a STM32 (STM32F030) I digitize the signal and generate a PWM. This PWM passes through a low pass filter and is then delivered to a small audio amplifier (TPA6205A).
In this direct soundcheck test, I'm having some white noise in the output, along with the music.
Some data:
All RC filters were calculated for fc = 10KHz;
The sampling frequency (cycle) is 40KHz;
The frequency of the PWM signal is 187KHz;
The ADC is to take readings of 8bits, and PWM is written in 8-bit too.
Does anyone have any idea or advice I can follow?
In this link you can download a short video that shows the circuit and its audio output.
**broken link removed**
**broken link removed**
Thank you very much.
Greetings,
I made a small circuit to be able to test some experience with signal processing.
Basimente I do input audio (with its analog circuit) using a STM32 (STM32F030) I digitize the signal and generate a PWM. This PWM passes through a low pass filter and is then delivered to a small audio amplifier (TPA6205A).
In this direct soundcheck test, I'm having some white noise in the output, along with the music.
Some data:
All RC filters were calculated for fc = 10KHz;
The sampling frequency (cycle) is 40KHz;
The frequency of the PWM signal is 187KHz;
The ADC is to take readings of 8bits, and PWM is written in 8-bit too.
Does anyone have any idea or advice I can follow?
In this link you can download a short video that shows the circuit and its audio output.
**broken link removed**
**broken link removed**
Thank you very much.
Greetings,