how to measure the coin cell battey voltage in real

[MARTIN FR]

Hello Everyone,

I am trying to measure the (3v)battery voltage by having proximity example as reference but intially it is showing 100percent later it is going to 13(percent) voltage approxmiatelry (after 120seconds) i dont understand why it is happening like this can anyone suggest me some possible ways to measure out by using multimeter how much voltage available on ADC pin ? so that i can able to make some idea about the battery level measurement§?

[Einar Thorsrud]

The proximity example in SDK 11 uses a app timer to measure the battery level. The first measurement is not performed until the first time it times out, and the timeout is 120 second (thus measurements are performed every 120 seconds). You can modify BATTERY_LEVEL_MEAS_INTERVAL and set it to a lower value in order to measure more often. You can also do the first measurement at startup, rather than waiting the full measurement interval before doing the first measurement.

Also, if you are not using the DK you may have to change the value of DIODE_FWD_VOLT_DROP_MILLIVOLTS to reflect your hardware.

[MARTIN FR]

thank you so much for your kind reply yes i understood the ADC configuration but am providing the supply via battery (2.91V )on VDD and am using NRF_ADC_CONFIG_SCALING_INPUT_ONE_THIRD; so it will come around like this VDD/3 where 1.455 is the VBG reference voltage so can you tell me is it possible to check the ADC _VALUE in the UART terminal(putty log) so that i can do some manual calcualtion to find out how much voltage left in battery, please verify my assumption are correct about ADC configuration? and also am using nrf_adc_input_select(NRF_ADC_CONFIG_INPUT_2);is function for the analog input pin