Hi guys


I programmed a microcontroller and it samples 200 times on a value of voltage, I want to reduce the noise affecting on the signal, so i sum samples and then divide by 200. But result is not very good, it still have some variation.


Can you recommand a better way to do it


Thanks

Gary Wang

 

External RC filter.

 

To answer this one correctly we need to know the nature of the signal being sampled. Is it DC with noise, and how much noise. But RC filter close to micro is the start and make sure Vref is clean to.

 

Also, if its line noise 50Hz make sure you sample over many cycles. Put a delay between the samples.

 

It output by DAC, and each step, It measures 200 times and I placed a simple RC filter at the ADC input. and also the RC low pass filter cutoff frequency is twice of ADC sampling rate

 

Also, if its line noise 50Hz make sure you sample over many cycles. Put a delay between the samples.

If it is line frequency noise, make sure that you sample over an exact integral number of complete cycles. For example, if it is 50Hz AC noise, sample for a complete cycle of 20ms duration or any multiple of 20ms.