Chapter 22 Matrix Keypad
244
Python Code 22.1.1 MatrixKeypad
First observe the project result, and then analyze the code.
1.
Use cd command to enter 22.1.1_MatrixKeypad directory of Python code.
cd ~/Freenove_Ultimate_Starter_Kit_for_Raspberry_Pi/Code/Python_Code/22.1.1_MatrixKeypad
2.
Use python command to execute code "MatrixKeypad.py".
python MatrixKeypad.py
After the program is executed, press any key on the MatrixKeypad, the terminal will print out the
corresponding key code. As is shown below:
The following is the program code：
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22
i m port
RPi
.
GPIO
a s
GPIO
i m port
Keypad
#import module Keypad
ROWS
=
4
# number of rows of the Keypad
COLS
=
4
#number of columns of the Keypad
keys
=
[
'1'
,
'2'
,
'3'
,
'A'
,
#key code
'4'
,
'5'
,
'6'
,
'B'
,
'7'
,
'8'
,
'9'
,
'C'
,
'*'
,
'0'
,
'#'
,
'D'
]
rowsPins
=
[
12
,
16
,
18
,
22
]
#connect to the row pinouts of the keypad
colsPins
=
[
19
,
15
,
13
,
11
]
#connect to the column pinouts of the keypad
d e f
loop
( ):
keypad
=
Keypad
.
Keypad
(
keys
,
rowsPins
,
colsPins
,
ROWS
,
COLS
)
#creat Keypad object
keypad
.
setDebounceTime
(
50
)
#set the debounce time
w h ile
(
True
):
key
=
keypad
.
getKey
()
#obtain the state of keys
i f
(
key
! =
keypad
.
NULL
):
#if there is key pressed, print its key code.
p r int
(
"You Pressed Key : %c "
% (
key
))
i f
__name__
= =
'__main__'
:
#Program start from here
p r int
(
"Program is starting ... "
)
t r y
:
Summary of Contents for Ultimate Starter Kit
Page 1: ...Free your innovation Freenove is an open source electronics platform www freenove com ...
Page 117: ...117 Chapter 9 Potentiometer RGBLED www freenove com support freenove com Hardware connection ...
Page 155: ...155 Chapter 14 Relay Motor www freenove com support freenove com Hardware connection OFF 3 3V ...
Page 173: ...173 Chapter 16 Stepping Motor www freenove com support freenove com Hardware connection ...
Page 239: ...239 Chapter 22 Matrix Keypad www freenove com support freenove com Circuit Schematic diagram ...
Page 240: ...Chapter 22 Matrix Keypad 240 www freenove com support freenove com Hardware connection ...
