Hi,
I can´t help with the PIC..
Is the numbering of the ADC channels correct? --> When you select channel6, is this referring to correct port pin?
but some hints, if you don´t mind.
* a capacitor next to the ADC input pins helps to make readings more stable
* a display update every 300ms is enough, so i recommend to use a 300ms dely in your main loop
* It may be a 10 or 12 bit ADC, so you factor 0.00977517106549364613880742913001 won´t make a difference to: 0.009775. Even the precision of a 32 bit float is limited to : 0.009775171
I wonder if the compiler can handle your value.
* The factor values make me think you want a precise measurement. But on the other hand it seems you use VCC as reference. Can you rely on VCC to be that accurate?..with change in load current, temperature, time...
* you should use bulk and decoupling capacitors on VCC, VREF and other importand voltages.
Klaus