SunFounder Thales Kit, Manual

Page: 104 / 167

SunFounder Thales Kit for Raspberry Pi Pico, Release 1.0
(continued from previous page)
rclk . high()
time . sleep_ms( 5 )
while True :
for num in range ( 10 ):
hc595_shift(SEGCODE[num])
time . sleep_ms( 500 )
When the program is running, you will be able to see the LED Segment Display display 0~9 in sequence.
How it works?
hc595_shift() will make 74HC595 output 8 digital signals. It outputs the last bit of the binary number to Q0,
and the output of the first bit to Q7. In other words, writing the binary number “00000001” will make Q0 output high
level and Q1~Q7 output low level.
Suppose that the 7-segment Display display the number “1”, we need to write a high level for b, c, and write a low
level for a, d, e, f, g, and dg. That is, the binary number “00000110” needs to be written. For readability, we will use
hexadecimal notation as “0x06”.
• Hexadecimal
• BinaryHex Converter
Similarly, we can also make the LED Segment Display display other numbers in the same way. The following table
shows the codes corresponding to these numbers.
Table 2: Glyph Code
Numbers Binary Code Hex Code
0 00111111 0x3f
1 00000110 0x06
2 01011011 0x5b
3 01001111 0x4f
4 01100110 0x66
5 01101101 0x6d
6 01111101 0x7d
7 00000111 0x07
8 01111111 0x7f
9 01101111 0x6f
Write these codes into
hc595_shift()
to make the LED Segment Display display the corresponding numbers.
3.4.17 Liquid Crystal Display
LCD1602 is a character type liquid crystal display, which can display 32 (16*2) characters at the same time.
As we all know, though LCD and some other displays greatly enrich the man-machine interaction, they share a com-
mon weakness. When they are connected to a controller, multiple IOs will be occupied of the controller which has
no so many outer ports. Also it restricts other functions of the controller. Therefore, LCD1602 with an I2C bus is
developed to solve the problem.
• Inter-Integrated Circuit - Wikipedia
100 Chapter 3. For MicroPython User