Problem with voltage divider
This is a common problem with voltage dividers when you feed the value into something which does not have a high enough resistance.







simulate this circuit &ndash; Schematic created using CircuitLab

As you see in the above circuit, without the load the divider gives you half the applied voltage. With the load in parallel with the bottom resistor, you get 1/3 the voltage.

You can significantly reduce the resistances you use for the divider so they are much smaller than the load resistance to reduce this effect, or you can buffer the voltage with a voltage follower circuit.







simulate this circuit

UPDATE:

Now you have added a schematic it is apparent your problem is your resistors are far too small. \$232\Omega\$ will draw over \$20mA\$ from 5V, but your IC can only deliver 10mA. As such your divider is pulling down the output. 

Use something like 82K and 150K resistors.