why proximity example shows always 100 battery

[karan]

Hello,

I am trying to make battery service in my application so i refer the proximity example in SDK 9 and i flashed into my kit it showing always 100percent in the nordic app what needs to be done inorder t monitor the exact battery voltage interms of percentage in nordiac app ? i am new to this field so any sugeestion will be useful for me

Thank you

[monpetit]

Look at the code. It probably says like this:

static void adc_configure(void)
{
    ...
    nrf_adc_input_select(NRF_ADC_CONFIG_INPUT_DISABLED);
    ...
}

Change adc input pin to NRF_ADC_CONFIG_INPUT_0 ~ NRF_ADC_CONFIG_INPUT_7 properly and test again.

[karan]

i did not see any lines like that in the ADC configure function

/**@brief Function for configuring ADC to do battery level conversion.
 */
static void adc_configure(void)
{
    uint32_t err_code;
    nrf_adc_config_t adc_config = NRF_ADC_CONFIG_DEFAULT;

    // Configure ADC
    adc_config.reference  = NRF_ADC_CONFIG_REF_VBG;
    adc_config.resolution = NRF_ADC_CONFIG_RES_8BIT;
    adc_config.scaling    = NRF_ADC_CONFIG_SCALING_SUPPLY_ONE_THIRD;
    nrf_adc_configure(&adc_config);

    // Enable ADC interrupt
    nrf_adc_int_enable(ADC_INTENSET_END_Msk);
    err_code = sd_nvic_ClearPendingIRQ(ADC_IRQn);
    APP_ERROR_CHECK(err_code);

    err_code = sd_nvic_SetPriority(ADC_IRQn, NRF_APP_PRIORITY_LOW);
    APP_ERROR_CHECK(err_code);

    err_code = sd_nvic_EnableIRQ(ADC_IRQn);
    APP_ERROR_CHECK(err_code);
}

[karan]

can you tell me do i have add any information in the ADC configure function?

[monpetit]

Sorry for the confusion, it was my fault for using the example of SDK 10.0.0.

You should use void nrf_adc_input_select(nrf_adc_config_input_t input) before nrf_adc_start().

For example:

static void battery_level_meas_timeout_handler(void * p_context)
{
    UNUSED_PARAMETER(p_context);
    nrf_adc_input_select(NRF_ADC_CONFIG_INPUT_0);
    nrf_adc_start();
}

Happy coding... :)

[karan]

Thanks for your reply but still in the nordic app am getting only 100 percent response and i have connected and tested with battery and usb power supply to see the measurementS am getting 100 only

[monpetit]

I see. Look at adc_config.reference = NRF_ADC_CONFIG_REF_VBG; In this case, adc measurement range is from 0 to 3.6V. If battery voltage is exceeds 3.6V you have to use voltage divider with resistors.