Another illustration how to wire the HT621 driven 6 Digit 7 Segment LCD Display on Microcontroller. This module is widely used in multi-meter, voltage monitor, solar power monitor, clock, thermometer, electronic measuring device, automotive, etc. this module is compatible in your favorite Microcontroller using 3 wire SPI communication and it has a backlight suitable in dark environment. This module runs on 4.7~5.2V DC 0.4mA without back-light and 4mA with back-light.
Arduino Microcontroller, ESP8266 12, 12E, ESP8266 NodeMCU, ESPDuino, WeMos, ATMEGA328 16/12, ATMEGA32u4 16/8/ MHz, ESP8266, ATMEGA250 16 MHz, ATSAM3x8E, ATSAM21D, ATTINY85 16/8 MHz (Note: The Diagram below is using NANO. If your using other MCU please refer to the respective pin-outs6 Digit 7 Segment 2.4 Inch LCD Display ModuleJumper Wires / DuPont Wire
See above schematics for wiring the LCD Display Module.
Source Code and Code segment address mapping can be found