How to rescale -10..10V to 0..5 V?
simulate this circuit &ndash; Schematic created using CircuitLab

An op amp circuit with a gain of 0.25 (so the voltage range is reduced from 20 to 5). With this alone you get an output of -2.5 to +2.5 volts. Then use two resistors in a voltage divider to put the + input of the op amp at a fixed 2.5 volts. This shifts the circuit output up to 0 to +5.