Overcome cross effects Character LCD Modules

In the dynamic drive mode, to make such a position (i, j) point display, on the need in the i th column and j th row selection voltage is applied at the same time, so that the point of the maximum electric field strength, but this time in addition to (i, j) points, the i-th row and j th row of the remaining points can withstand a certain voltage, these points are called semi-selected point. If the semi-selected point of the effective voltage is greater than the threshold voltage, there appears on the screen should display the contrast decline, which is cross effects. The way to solve the cross effect is the average voltage method, that is, the semi-selected point and non-selected point average of the voltages, an appropriate increase in the non-selection voltage to offset the point on the semi-selected point of the voltage, the semi-selected point on the voltage drop, improve display contrast.
Pixel Control
Pixel by pixel register and a status bit is uniquely determined. There are 16 pixel lcd module registers to control up to 4 × 29 = 116 pixels. We use the LCD from 8 × 8 = 64 pixels. Thus, the pixel data register is sufficient.
Segment Enable
Segment code is enabled by LCDSE registers. Because VIM807-2 is eight 7-segment display, and our choice is 1/3 duty cycle (ie, three common), so by LCDSE register must choose 3 × 8 = 24 segments in order to meet the need, namely complete expression All of the code segment pixels. Of course there will be superfluous, 8 × 9 = 72, because every three commons and 3 above can express 9 pixels.
LCD drive voltage generating
LCD drive voltage is generated in two ways, the internal charge pump method or external resistor ladder network method. Since the Character LCD Module charge pump is in development, in order to reduce design risk, we use a more sophisticated method of external resistor ladder network. Using an external resistor ladder network, VGEN (LCDCON <4>) should be cleared.