Can I measure battery level without any external components nrf51

[Mikhail]

I want to undestand this. I can't see any examples with it. In the example ble_app_proximity I always received 100% level. If it possible, can anybody give a ADC config example for it? Thanks.

[endnode]

Read this.

[Mikhail]

I tryed this example. Doesn't work on my SDK9. This example for SDK11. I mean than I can't compile

static nrf_drv_adc_channel_t adc_channel_config = NRF_DRV_ADC_DEFAULT_CHANNEL(NRF_ADC_CONFIG_INPUT_2);

there is no

nrf_drv_adc_channel_t 

struct in SDK9