Converting ADC output to real values
It looks like you have a 16-bit, 2's-complement ADC with a range of \$-5V \le V_{IN} &lt; 5V\$. If that's the case, then the digital values can be interpreted as signed integers from -32768 to +32767. The measured voltage is

\$ V_{IN} = \frac{DigitalValue}{32768} \times 5\$