Compute RMS from SAADC sample buffer

[Jakub]

Hello, 

I am currently sampling SAADC every 1ms using PPI. Samples are collected in predefined buffer, and then send over BLE with ble_nus_data_send() function.

I would like to slightly modify my software and compute RMS value from samples gathered in buffer, and then send single RMS-value with ble_nus_data_send() function, hence my question.

Is there any exemplary software provided by Nordic Semiconductors to compute RMS from SAADC samples?

Thank you in advance for your reply, Jakub.

[Håkon Alseth]

Hi,

 

We do not have any libraries for this specifically.

You could use SAADC oversampling, or manually sample 'n' amount of times and average this.

 

Best regards,

Håkon

[Jakub]

would it be ok if I use arm_math.h to compute RMS value of collected samples?

[Håkon Alseth]

Yes, you can use arm_math and other math/dsp-libraries if you require those.

 

Cheers,

Håkon

[Jakub]

Ok, thank you for your help ;)