Stm32f1 and stm32subeide programming example -max7219 drives 8-bit 7-segment nixie tube (based on GPIO)

MAX7219 drive 8 position 7 Segment nixie tube ( be based on GPIO)

1、MAX7219 Introduce

MAX7219/MAX7221 Is a compact serial input / Output common cathode display driver , Microprocessor (μPs) Connect to up to 8 Bit 7 Segment number LED Monitor 、 Bar graph display or 64 Independent LED. On chip includes BCD Code B decoder 、 Multiplex scanning circuit 、 Segment and digital drive, as well as the 8x8 static state RAM. Only one external resistor is needed to set all LED The current of the section . MAX7221 And SPI、QSPI and MICROWIRE compatible , And a segment driver with limited swing rate to reduce EMI.

A convenient 4 Line serial interface connects to all common μP. You can address and update individual numbers without rewriting the entire display . MAX7219 It also allows the user to choose for each number code-B Decode or not .

These devices include a 150μA Low power shutdown mode 、 Analog and digital brightness control 、 One allows users to display 1 To 8 Bit digital scan limit register , And a mandatory all LED Illuminated test mode .

MAX7219 Has the following characteristics ：

• 10MHz serial interface
• A separate LED Segment control
• decode / No decoded digital selection
• 150μA Low power shutdown （ Data retention ）
• Digital and analog brightness control
• The display is blank when powered on
• Drive common cathode LED display
• For lowering EMI Limited swing rate segmented driver (MAX7221)
• SPI、QSP