ADC VALUE MEASUREMENT IS FLUCTUATING.

[NANDHU]

Hi,

• In our  project we are using the adc pin (p02) for batttery level measurement.
• The analog dc signal from the battery is connected to p02 pin after the voltage is divided into half by using an voltage divider circute.

PROBLEM

• When we measure the voltage of battery using the oscilloscope . The ripples in the input dc signal is 160 mv.

• Look the above figure .

We want to reduce these ripple from the dc input signal . We are planning to place a capacitor to ground before the adc pin for removing  the ripples ,Is these a proper way?

Our adc readings are fluctuating so much .I think these changes will reduce the adc value fluctuation ,is it right?

Please help me to solve these issue .

If you need any further input please ask.

    

[Kenneth]

Please check out:
https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/measuring-lithium-battery-voltage-with-nrf52

You can find that we suggest a 10nF capacitor.

Best regards,
Kenneth

[NANDHU]

kenneth,

   What are the different methods we can implement in software part to remove the adc value fluctuation. 

[Kenneth]

There should already be some recommendations in the blog post and comments below, but in addition I would check out using oversampling the input, but also schedule the ADC measurement between other activity, such that that the device for instance does not run peak radio currents and/or motors and/or leds that may draw excessive current during the battery measurements.

Kenneth