Can C51 chips not drive too large LED dot matrix?
In the practical application is not directly with the MCU to control LED dot matrix, will increase the current drive circuit, because the MCU port can output or pull into the very limited, regardless of other factors that, if not the current brightness will LED, in the laboratory can work, especially to the outside of what may the invisible light is sufficient. In other words, SCM is mainly used for control, drive, but also rely on other auxiliary circuit. Therefore, the "drive" of these two words is strictly inaccurate, and "control" may be more appropriate.
In practical applications, you can control more LED dot matrix by means of port expansion, for example, you can plug in and out chips through 74HC164, so that more I/O ports can be expanded to control more LED dot matrix.
Your friend said is not in the I/O expansion under the condition of the microcontroller 51 32 I/O mouth line, so you can use 16 LED array control, 16 column control, display through software to control 16*16 dot matrix LED. This method is more used for teaching materials or examples, used to explain the principle of single chip microcomputer and its application in LED dot matrix.
