Specification: 8 buttons 8 LEDs 8-digit digital tube, common cathode LED digital tube. VCC GND is connected to 5V power supply, STB CLK DIO is connected to IO port of MCU. Size: Approx. 7.5 * 5 * 0.8 cm / 2.95 * 1.97 * 0.31 in Package Weight: 25.3 g / 0.89 oz Package list: 1 * Key Digital Tube LED Display Module A Good Effect of Key Sensing Display: 8 Bits Digital LED Tube has a good effect of key sensing display, the display mode is 10 segments × 8 bits, and the key scan (8 × 3 bits), the digital display template is an 8-bit digital tube, and a common cathode LED digital tube. With Key Scan Interface: TM1638 Digital LED Key Digital Tube is an LED light-emitting diode display template with key scan interface, drive control circuit, integrated microcontroller digital interface, data latch, LED high voltage drive, keyboard scan circuit. With STC and Other Microcontroller: LED key digital tube can be directly connected with STC and other microcontroller, only need to occupy three IO port of the microcontroller to drive. Read And Write Relevant Register: The scan display and key scan of 8-bit LED module template do not need MCU intervention, only need to read and write the relevant register. Saving MCU Resources: Digital display module can send display data or test buttons to achieve the purpose of saving MCU resources.