资 源 简 介
This application note describes how to implement automatic contrastcontrol of an LCD (liquid crystal display) using the MC68HC08LN56microcontroller.In applications where the power supply voltage can vary, such as inbattery-powered systems, maintaining a constant contrast on the LCDdisplay is desirable. This can be achieved in software on theMC68HC08LN56 by using the A/D (analog-to-digital) converter inconjunction with the LCD controller.This application note discusses how factors such as the amount ofmultiplexing, type of bias, and voltage levels can affect LCD contrast.This is followed by a description of a system in which the A/D converteron board the MC68HC708LN56 samples the system power supply andthe contrast control for the LCD is updated based on the result.Also included here is the source code for implementing this system.
