Setting reference voltage with battery monitor li-soci2(3.6v) battery *Vrefint

[YBAYR.1]

hello everyone,
In a battery-powered IoT project, I can never make accurate measurements because my battery voltage is the same as my reference voltage. 

I did not use any power ICs to reduce the cost of my project.

I am using a 3.6V li-soci2 battery

Saving power is very important

I think I need to use VREFINT

I am using stm32f302r8t6

How to measure the battery level (battery monitoring) of a battery-saving system that works with a 3.6v battery?

[TDK]

Measure the VREFINT channel and use that to infer what VREF+ is. VREFINT has a constant voltage of ~1.21 (check datasheet for specific), so if the VREFINT channel measures as 1500, your VREF+ is 1.21 V * 4095 / 1500 = 3.3 V.

[YBAYR.1]

I'm very sorry but I couldn't understand

can you give me an example

I connected 3.6v (battery li-soci2) VDD and VREF+.
(4095 / VREFINT value)*1.21 = VDD
is this true?

[TDK · Accepted solution]

> is this true?

Yes

There are ADC examples in the repository that you can follow.

[YBAYR.1]

I understand, I'm really grateful.