Query about data coming out of STM32N6570-DK MCU

[chanchal94]

I am using ADC + DMA + USART1 + Timer in STM32 IDE in a setup consisting of:

Motor → Sensors → MCU (STM32N6) → PC

I am capturing the signal received at the serial port using NanoEdge AI. I have shared screenshots of:

• The actual current waveform observed on the oscilloscope

• The data received through the STM32N6 MCU

My doubt is:

Is there anything inside the MCU or ADC that could suppress or distort the natural sinusoidal shape of the current waveform?

Note:

• I have converted ADC values to actual current values using a 3.3V reference.

• I have removed the sensor bias.

• I have properly accounted for sensor gain.

I would like to confirm whether the MCU/ADC processing could be affecting the waveform shape

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Edited to place the images in the post:

 

[Andrew Neil]

Please use your scope's trace capture facility - it will give much better results than photographing the screen!

 

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@chanchal94 wrote:

Is there anything inside the MCU or ADC that could suppress or distort the natural sinusoidal shape of the current waveform?

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You need to set an appropriate sample rate!

Your graph shows that you are only sampling about once in each half-cycle ...

[chanchal94]

Thank you! I got the solution :)

[LCE]

@chanchal94 we're always happy if the solution is shared for the next person running across the same problem.

 

P.S.: ADC data over UART: people often forget / oversee that the UART's baud rate is not high enough for ADC data.

[chanchal94]

My baud rate was okay, it was the timer issue, I checked it again as @Andrew Neil pointed out about sampling rate, I found out baud rate+ timer settings should be correct for this. My timer setting was a bit distorted.