Chapter 14 74HC595 & 7-Segment Display

In this chapter, we will introduce the 7-Segment Display.

Project 14.1 7-Segment Display.

We will use 74HC595 to control 7-segment display and make it display hexadecimal character “0-F”.

Component List

  • ESP32-S3-WROOM x1

  • GPIO Extension Board x1

  • 830 Tie-Points Breadboard x1

  • 74HC595 x1

  • Resistor 220Ω x8

  • 1 Dight 7-segment Display x1

  • Jumper Wire

Connect

../_images/141.png

Code

In this section, the 74HC595 is used in the same way as in the previous section, but with different values transferred. We can learn how to master the digital display by sending the code value of “0” - “F”. Move the program folder Super_Starter_Kit_for_ESP32_S3/Python/Python_Codes to disk(D) in advance with the path of “D:/Micropython_Codes”.

Open “Thonny”, click This computer/D:/Micropython_Codes/14.1_74HC595_and_7_segment_display.

Select “my74HC595.py”, right click your mouse to select “Upload to /”, wait for “my74HC595.py” to be uploaded to ESP32-S3 and then double click“74HC595_and_7_se gment_display.py”.

14.1_74HC595_and_7_segment_display

../_images/14.11.png

Click “Run current script”，and you’ll see a 1-bit, 7-segment display displaying 0-F in a loop.

../_images/14.12.png

Code

The following is the program code:

import time
from my74HC595 import Chip74HC595

lists =[0x3f, 0x06, 0x5b, 0x4f, 0x66, 0x6d, 0x7d, 0x07,
        0x7f, 0x6f, 0x77, 0x7c, 0x39, 0x5e, 0x79, 0x71]

chip = Chip74HC595(12,13,14)
try:
    while True:
        for count in range(16):
            chip.shiftOut(0,lists[count])
            time.sleep_ms(500)
except:
    pass