I want to use self made VEE, then use the module without the VEE. How to decide the VEE value? How to connect?
Before deciding the VEE, we should know the module's Vop (VDD-VO) first. For example, WG12864A. VDD-VO is 9.4V when the temperature is 25 degrees. It means that when the VO reaches 9.4V, the display is the best.Vo is the differential voltage of VDD and VEE. If VDD is 3.3V, the VEE should be at least 6.1V to achieve the best display. But we suggest the VEE should not be just right. It is better to be bigger for 3V. For instance as above 6.1V+3V=9.1V.
The connection of the VEE is as follows.