how to calibrate PIC?

hello,

i use a PIC16f877a microcontroller, i have wrote a program, to read analog input:

int10 value;
value= read_adc();

when calibrate the PIC in real time... i need to know what the value had the PIC stored in the variable "value".....

the normal method i used is to output the value to a port with 8 pins, and connect each pins to a LED seperately, by reading the on-off LED, i covert it from binary to decimal....

now, if the value i stored is more than 8 bit... what should i do to read it? is there any better idea other than using LED?

I've no idea what you mean by 'calibrate'? - as for displaying it, you can use ten LED's, 7 segment displays, LCD modules, RS232 to a PC - there are load's of different ways.

The AD reading is ratiometric with respect to Vref (assuming the other end of the network is tied to GND). AD reading is INT(1023*Vin/Vref). What is there to calibrate?