You wrote:

"how we will do the relation between the measured hex value and the real value of the process variable"

Search the forum for code concerning to conversion from hex value to seven segments display.

The real value is what you get from the humidity sensor in your application. You must be aware that the scale input range of 80C535 is 0-5v.
Thus the resolution is 5v / 255 = 19,6mv . If the register hex value is A0H, that means 10 x 19,6mv = 196mv at convertor input. If these 196mv means 10% umidity you can display as 10. Just a very, very simple explanation. Do you understand how the DAPR register is used in 80C535, how you can increase/decrease the resolution and scale range, what is the ratio between analogic input value and digital inside 8bits micro ?


What is the output level of humidity sensor ? How the interface between the sensor and the micro will look like ?

Sorry no ofence, but if you encountered such problems now, I'm wonder how will behave on real implemented PCB.

Regards,
Silviu