Use 4-digi 3.6” 7-segment display, common anode, 12 pins
Only need two control pins, CLK and DATA (DIO)
Use common 7-segment control IC TM1637, widely used together with 7-segment in many cases, for example, small instruments, domestic appliance, etc. Also very simple peripheral circuits for TM1637. (Datasheet of this IC is NOT available now, only in Chinese)
Available to adjust brightness, 8 level gray scale