中职扩展资源包资料：树莓派系列教程9：按键

1、上两章我们讲解了在树莓派上如何点亮一个LED灯，这一章我们讲解一下按键以及事件中断。一、bcm283501 #in elude <bcm2835.h>02 #i nclude <stdio.h>0304 #defi ne KEY 2005 int main (i nt argc, char *argv)06 07if (!bcm2835_i nit()return 1;08 bcm2835_gpio_fsel(KEY, BCM2835_GPIO_FSEL_INPT);09 bcm2835_gpio_set_pud(KEY, BCM2835_GPIO_PUD_UP);10

2、 prin tf("Key Test Program!n");11 while (1)12 13 if(bcm2835_gpio_lev(KEY) = 0)14 15 printf ("KEY PRESS'n");16 while(bcm2835_gpio_lev(KEY) = 0)17 bcm2835_delay(100);18 19 bcm2835_delay(100);20 21 bcm2835_close();22 return 0;23 </stdio.h>v/bcm2835.h>编译并执行，按下按键会看到窗口显示”K

3、EY PRSStS+C,结陳程序。1 gcc -Wall key.c key Tbcm28353 sudo ./key注：(1 ) bcm2835_gpio_fsel(KEY, BCM2835_GPIO_FSEL_INPT);(2) bcm2835_gpio_set_pud(KEY, BCM2835_GPIO_PUD_UP);设置管脚为输入模式设置为上拉模式(3) bcm2835_gpio_lev(KEY);读取管脚状态二、wiringPi01 #in clude <stdio.h>02 #in clude<wiri ngpi.h>0304 char KEY = 29;

4、0506 int mai n()if (wiri ngPiSetup() < O)return 1 ; pinM ode (KEY,INPUT); pullUpD nCon trol(KEY, PUD_UP); prin tf("Key Test Program!n"); while(1)08091011121314151617181920if (digitalRead(KEY) = 0)printf ("KEY PRESS'n");while(digitalRead(KEY) = 0) delay(100); delay(100);21

5、22 </wiri ngpi.h></stdio.h>编译并执行，按下按键会看到窗口显示”KEY PRESS+C,纟按束程序。1 gcc -Wall key.c key -viringPi3 sudo ./key注：(1)pinMode (KEY,INPUT); 设置管脚为输入模式(2) pullUpDnControl(KEY, PUD_UP);设置为上拉模式(3) digitalRead(KEY);读取管脚状态通过中断的方式编程01 #i nclude <stdio.h>02 #in elude <wiri ngpi.h>0304 #defi

6、ne button 2905 char flag = 0;06 void myl nterrupt()07 08 flag +;09 1011 int mai n()12 13 if(wiri ngPiSetup() < 0)return 1;14 if(wiri ngPilSR(butt on ,INT_EDGE_FALLING,&myln terrupt) < 0)15 16 prin tf("U nable to setup ISR n");17 18 prin tf(" In terrupt test program' n&qu

7、ot;);19 while20 21 if(flag)22 0);23 while(digitalRead(butto n)=24 prin tf("button pressn");25 flag = 0;26 27 28 29 </wiri ngpi.h></stdio.h>编译并执行1 gcc -Wall Interrupt.c Interrupt -IwirngPi3 sudo ./In terrupt；设置中断下降沿触发,myInterrupt注: ( 1 ) wiringPilSR(button,INT_EDGE_FALLING,&

8、mylnterrupt)为中断处理函数。三、python01 #!/usr/bi n/pyth on02 # -*- codi ng:utf-8 -*-03 import RPi.GPIO as GPIO04 import time0506 KEY = 260708 GPIO.setmode(GPIO.BCM)09 GPIO.setup(KEY,GPION,GPIO.PUD_UP)10 while True:11 time.sleep(0.05)12 if GPIO.i nput(KEY) = 0:13 prin t("KEY PRESS")14 while GPIO.i

9、nput(KEY) = 0:15 time.sleep(0.01)执行程序，按下按键会看到窗口显示”KEY PRECSI+” ,按束程序。1 sudo pytho n key.py注：(1 ) GPIO.setup(KEY,GPIO.IN,GPIO.PUD_UP)设置管脚为上拉输入模式(2)GPIO.input(KEY )读取管脚值通过中断模式编程01 #!/usr/bi n/pyth on02 # -*- codi ng:utf-8 -*-03 import RPi.GPIO as GPIO04 import time0506 KEY = 260708 def MyI nterrupt(KE

10、Y):<spa n style="fo nt-size: 9pt; li ne-height:0925.2000007629395px;"></spa n>pri nt("KEY PRESS")1011 GPIO.setmode(GPIO.BCM)12 GPIO.setup(KEY,GPION,GPIO.PUD_UP)13 GPIO.add_eve nt_detect(KEY,GPIO.FALLING,Myl nterrupt,200)15 while True:<spa n style="fo nt-size: 9pt; li ne-height:1625.2000007629395px;"> </spa n>t