Problem: recovering ADC value

[titouancurt]

I've been stuck for several days retrieving adc values from the mp23abs1 analog microphone on my stevalmksbox1v1. I just want to test to see if the adc values fluctuate according to the sound level where I am, but nothing moves. In debug mode in live expressions, I still have a fixed adc value between 4020 and 4024. My code in main is as follows:

uint16_t ADC_VAL = 0;
int count = 0;

HAL_ADC_Start(&hadc1);

while (1)
{
   HAL_ADC_PollForConversion(&hadc1, 100);
   ADC_VAL = HAL_ADC_GetValue(&hadc1);

   HAL_Delay(500);
   count ++;
}

I have attached the configuration of my ioc. The aim is to make a sound level meter, so to get the audio signal from the microphone and convert it into DB SPL. This is for a project in my engineering school. Thank you in advance for your help.

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Code formatting applied - please see How to insert source code for future reference.

[Andrew Neil]

Welcome to the forum.

Please see How to write your question to maximize your chances to find a solution - we need more details!

Have you tried the ADC with just a steady input - eg, from a potentiometer?

[TDK]

Use DMA to convert many ADC values into a circular buffer. Slow down sampling rate to something manageable and realistic for a microphone.