mcp3202 output

[glk.c.93]

hi...
I am trying to use ADC through MCP3202 and pic16F877A by SPI comm.
I am getting 4095 at around 4 volts
From 4v to 5v i am getting the same value.
Hence i am unable to identify the value of voltage in between 4-5v and display it on a lcd.
I had given the reference voltage as 5v.

what might the problem be?
Is there any thing to be done for measuring 4to5v range too?
what does the pin VREF do?
What difference do we see if we vary the value of VREF?

[temtronic]

Without seeing your code or schematic it is very,very difficult to tell you exactly where the problem is..
...you should supply us with more information.

hardware...although you say you're getting the correct values from 0 -4 VDC there might be an issue...

software...I don't use that chip but is it 8 bit,10 bit,12 bit ADC ?
What is the ADC result variable declared as?
If >8bit do you correctly read both high and low bytes of data,then 'make' into the proper word.
Perhaps you're not setting up the ADC chip right, slecting 8 bit mode when you want 12 bit mode?
Display of data may be formatted wrong..

Again, without seeing your code it is hard to say what your error is.

hth
jay