According to the different LED nixie drive mode, can be divided into static and dynamic two categories.
1. Static drive mode
Static drive is also called DC drive. Static drive means that each section of the nib code is driven by a single chip I/O port, or by using a binary converter such as BCD code. Static driver has the advantage of simple programming, display high brightness, the disadvantage is to occupy I/O port, such as drive 5 digital tube static display need 5×8=40 I/O port to drive, want to know an 89S51 microcontroller available I/O eloquence 32. As a result, drivers need to be added to drive practical applications, which increases the complexity of hardware circuits.
2. Dynamic drive mode
Digital tube dynamic display interface is one of the most widely used display methods in single chip microcomputer, dynamic drive is all the digital tube 8 display strokes "a, b, c, d, e, f, g, dp" end together, in addition to the common pole COM for each digital tube to increase the gate control circuit, the gate is controlled by its own independent I/O line.
When the single chip outputs the glyph code, all nibbles will receive the same glyph code, but which nibbles will display the glyph depends on the single chip's control of the bit gate COM circuit, so as long as we need to display the gate control of the nibbles, the bit will display the glyph, and none of the gate of the nibbles will light up.
Through time-sharing control of each LED digital tube COM end, so that each digital tube control display in turn, this is dynamic drive. During the rotating display, each nixie tube is lit for 1~2ms. Due to the phenomenon of human visual retention and the afterglow effect of LED, despite the fact that none of the nixie tubes are lit up at the same time, the impression will be given as a stable set of display data, without flickering, provided the scanning speed is fast enough. Dynamic display has the same effect as static display. Can save a lot of I/O ports, and reduce power consumption.