Battery Voltage Monitor using Resistor network

[alleekhaan]

Hi,

I am using nRF52832 module BL652. I want to measure the battery voltages of a 9V battery.

What are the best possible resistors value to measure voltage of such battery(7.2 to 9.6V)?

I read this blog but it is about nRF51 and they mentioned that both ADC are different.

So any suggestion for nRF52832 please

Thanks

[ketiljo]

You can use the method described in the blog post you refer to. Just make sure the voltage on the AIN pin doesn't exceed VDD at any time.

[alleekhaan]

Hi ketiljo 
Thanks for your reply
My concern is about other parameters mentioned in the blog than just a voltages.  I can adjust the output voltages using divider but they specifically mentioned few other parameters in that blog. Also, it is about nRF51 but not nRFR52. Both have different ADC.

Thanks

[ketiljo]

The blog is made for the nRF52 but is valid for both nRF51 and nRF52

[alleekhaan]

Hi ketiljo 
What resistors values you advise for the voltage divider to reach input voltages in the range of 6 to 10V?

I know it's a very basic question but i am a bit confused about.
If i choose R2 = 2M  and R1 = 4.67M.will it work?

Thanks

[ketiljo]

The output of the voltage divider will be:

Vin * R2 / (R1+R2)

So at 10 V:

10 V * 2 / (2 + 4.67) = 2.99 V

Should be ok