I tried SAADC on Dynastream D52 module. Im not understanding the value read

[Nats]

Hello,

I successfully downloaded SAADC SDK example in the peripheral folder. The hardware setup is as below , 

The pin configuration for this is as below

When i connect to J102.01 to GND pin, i get the values as below.

Kindly help me with, How to read this value ?

[Kenneth]

In an perfect world the value would be 0 if you connected the input to GND. However an ADC have for instance offset and gain error, and thermal noise affect individual readings, so a value of (assuming 10bit): 30 / 1024 * VDD(assuming 3V) = 88mV is not the far off. However, you may consider running nrf_drv_saadc_calibrate_offset() during saadc_init(). This should reduce the offset error.

[Nats]

Thank you @Kenneth for the detailed explanation.