RAK3172 + RUI3 + Battery Voltage API

[dinesh (Dinesh Ananda Lohar)]

Hi,

Greetings!

We are using RAK3172 based board and we wish to understand how Battery API works in RUI3.

System

We wish to understand which GPIO (ADC) is used to measure battery voltage and how it is connected.

Regards,

Dinesh

[beegee (Bernd Giesecke)]

The battery API is made for the usage with the Evaluation Board. If you want to use it with the stamp module, the battery voltage divider should be connected pin32 of the stamp module, ADC1.
The required voltage divider to use the battery API is 1M Ohm 1.5M Ohm

[dinesh (Dinesh Ananda Lohar)]

Thanks for such a fast reply

[Schulz (Ernst)]

The funktion doesn’t work! (Rak3172)

Even with the latest firmware (hex) from 14.09.22 the error is still present!

Greetings

E_t

[beegee (Bernd Giesecke)]

@Schulz

What error? This thread is about reading the battery voltage, there is no error mentioned here.

[Schulz (Ernst)]

The API read an AD-value from the AD-Converter. The AD-converter get’s the reference-voltage from the battery, not from intern reference-voltage, so the result is wrong, because the reference-voltage from battery has the same variation as the voltage to be measured (Breakoutboard Pin 3.3V). In my test the value is allways the same!

Hi [**@dgois100**](https://forum.rakwireless.com/u/dgois100) ,

CR2032 will have a voltage around or less than 3V. Currently, the default VRef of ADC is VDD voltage. It means that you will not be able to track the voltage level properly. We have an API that can set the voltage reference but it seems to have issue at the moment.

E_T