A modulator can include a common signal modulator that outputs a predetermined number of common signals to a multiplexer interface liquid crystal display (MUX LCD) based on an output state of a set of general purpose input/output (GPIO) pins of a controller, wherein each common signal has at least four bias levels. The modulator can also include a segment signal modulator that outputs a predetermined number of segment signals to the MUX LCD based on an output state of another set of GPIO pins of the controller, wherein each segment signal has at least three bias levels.