Features: 8 Bits, 8 keys, 8 LEDs, 8 digital tubes, common cathode LED digital tube. With TM1638 chip, this module gather more than three common SCM peripheral circuits. SCM doesn't need to work for scanning display and key scanning. It only need to read the relevant register to send display data or test button so it save MCU resources effectively. Keys are sensitive and display effectively. Can be directly connected with STC MCU The advantage is only three IO port will be occupied when it drives. Specification: Model: TM1638 Material: Glass fiber reinforced plastic, PBT shell, PA blades Size: 7.7 x 5cm / 3.03 x 1.97in Weight: 26g How to connect: VCC GND: 5V power supply, STB CLK DIO SCM: IO port. Package included: 1 * TM1638 Display module 1 * Flexible Flat Cable 1、8 Bits, 8 keys, 8 LEDs, 8 digital tubes, common cathode LED digital tube 2、With TM1638 chip, this module gather more than three common SCM peripheral circuits. 3、SCM doesn't need to work for scanning display and key scanning 4、It only need to read the relevant register to send display data or test button so it save MCU resources effectively 5、Keys are sensitive and display effectively