1. First need to understand the structure of a digital tube.

     2. Common anode and common cathode digital tubes, the common terminal is the middle pin. The common cathode digital tube needs to connect the common terminal to GND, and the common anode digital tube needs to connect the common terminal to VCC.

     3. The nixie tube is a semiconductor light-emitting device, and its basic unit is a light-emitting diode. The nixie tube is divided into seven-segment nixie tube and eight-segment nixie tube according to the number of segments. Eight-segment nixie tube has one more LED unit (one more decimal point) than seven-segment nixie tube

     4. Common anode digital tube refers to a digital tube that connects the anodes of all light-emitting diodes together to form a common anode (COM). The common anode digital tube should be connected to the common pole COM to +5V during application. When the cathode of a certain field of the light-emitting diode is low, the corresponding field will be lit. When the cathode of a certain field is high, the corresponding field is not lit.