【MYD-JX8MMA7】 （二）GPIO控制-Python&C

一、C语言LED

1.程序代码

/* Copyright 2018 Tronlong Elec. Tech. Co. Ltd. All Rights Reserved. */

#include <stdio.h>

#include <stdlib.h>

#include <stdint.h>

#include <stdbool.h>

#include <string.h>

#include <getopt.h>

#include <signal.h>

#include <unistd.h>

#include <errno.h>

#include <libgen.h>

/* Get array size */

#define ARRAY_SIZE(array) sizeof(array) / sizeof(array[0])

/* User-operable LEDs */

static char *g_leds[] = {

"/sys/class/leds/user1",

"/sys/class/leds/user1",

"/sys/class/leds/user1",

"/sys/class/leds/user1"

};

/* Exit flag */

volatile bool g_quit = false;

/* Short option names */

static const char g_shortopts [] = ":n:vh";

/* Option names */

static const struct option g_longopts [] = {

{ "number", required_argument, NULL, 'n' },

{ "version", no_argument, NULL, 'v' },

{ "help", no_argument, NULL, 'h' },

{ 0, 0, 0, 0 }

};

static void usage(FILE *fp, int argc, char **argv) {

fprintf(fp,

"Usage: %s [options]\n\n"

"Options:\n"

" -n | --number Number of LEDs, range of 1 to 4 \n"

" -v | --version Display version information\n"

" -h | --help Show help content\n\n"

"", basename(argv[0]));

}

static void opt_parsing_err_handle(int argc, char **argv, int flag) {

/* Exit if no input parameters are entered */

int state = 0;

if (argc < 2) {

printf("No input parameters are entered, please check the input.\n");

state = -1;

} else {

/* Feedback Error parameter information then exit */

if (optind < argc || flag) {

printf("Error: Parameter parsing failed\n");

if (flag)

printf("\tunrecognized option '%s'\n", argv[optind-1]);

while (optind < argc) {
            printf("\\tunrecognized option '%s'\\n", argv[optind++]);
        }
        
        state = -1;
    }
}

if (state == -1) {
    printf("Tips: '-h' or '--help' to get help\\n\\n");
    exit(EXIT_FAILURE);
}

}

void sig_handle(int arg) {

g_quit = true;

}

int main(int argc, char **argv) {

int i = 0;

int c = 0;

int num = 0;

int flag = 0;

char cmd[64] = {0};

/* Parsing input parameters */
while ((c = getopt_long(argc, argv, g_shortopts, g_longopts, NULL)) != -1) {
    switch (c) {
    case 'n':
        num = atoi(optarg);
        break;

    case 'v':
        /* Display the version */
        printf("version : 1.0\\n");
        exit(EXIT_SUCCESS);

    case 'h':
        usage(stdout, argc, argv);
        exit(EXIT_SUCCESS);
            
    default :
        flag = 1;
        break;
    }
}

opt_parsing_err_handle(argc, argv, flag);

/* Check if the number of LEDs is out of preset range */
if ((num > ARRAY_SIZE(g_leds)) || (num < 1)) {
    printf("Error: The number of LEDs entered exceeds the preset range(1-4)\\n");
    exit(EXIT_FAILURE);
}

/* Ctrl+c handler */
signal(SIGINT, sig_handle);

/* Print LEDs */
printf("\\nSystem leds :\\n");
system("find /sys/class/leds/*");

printf("\\nFlashing leds :\\n");
for (i = 0; i < num; i++)
    printf("%s\\n",g_leds[i]);

while (!g_quit) {
    /* Turn on LEDs */
    for (i = 0; i < num; i++) {
        /* Set the LED brightness value to 1 to turn on the led */
        snprintf(cmd, 64, "echo 1 > %s/brightness", g_leds[i]);
        if (system(cmd) != 0) {
            fprintf(stderr, "Error: Failed to turn on %s\\n", g_leds[i]);
            exit(EXIT_FAILURE);
        }
    }

    /* Keep the LEDs on for 500 ms */
    usleep(500 * 1000);

    /* Turn off LEDs */
    for (i = 0; i < num; i++) {
        /* Set the LED brightness value to 0 to turn off the LED */
        snprintf(cmd, 64, "echo 0 > %s/brightness", g_leds[i]);
        if (system(cmd) != 0) {
            fprintf(stderr, "Error: Failed to turn off %s\\n", g_leds[i]);
            exit(EXIT_FAILURE);
        }
    }

    /* Keep the LEDs off for 500 ms */
    usleep(500 * 1000);
}

printf("Exit\\n");
return 0;

}

2、makefile 代码

tl_led_flash:tl_led_flash.c
(CC) -Wall < -o $@

clean:

rm -f tl_led_flash *.o *~

install:

cp tl_led_flash $(PREFIX)

2.将代码文件和makefile文件上传到开发板

3.LED引脚查看

因为开发应用程序需要知道系统内LED的定义

4.代码编译和运行

5.开发板上蓝色LED正常按设计交替闪烁。

二、Python代码

1.python代码

Python代码文件尾椎是.py,python代码属于脚本文件，所以不用在进行编译，相对很方便。

#!/usr/bin/env python3

- - encoding: utf-8 - -

'''

[url=home.php?mod=space&uid=1455510]@file[/url] : tl_led_flash.py

[url=home.php?mod=space&uid=26400]@TIME[/url] : 2020/04/26 09:05:54

[url=home.php?mod=space&uid=284375]@desc[/url] : None

'''

here put the import lib

import signal, time

import os, sys, getopt

version = "1.0"

class Led(object):

quit_flag = False

def __init__(self, led_path):
    self.led_path = led_path    # Led path
    self.leds     = []          # Save the led found

""" enumerate all led """
def enumerate_led(self):
    led_name = "user1"

    """ find led """
    for filename in os.listdir(self.led_path):
        if led_name in filename:
            self.leds.append(os.path.join(self.led_path, filename))

    if len(self.leds) == 0:
        return False

    """ 
    led sort, e.g.
    /sys/class/leds/user-led0
    /sys/class/leds/user-led1
    /sys/class/leds/user-led2
    """
    self.leds.sort()

    print ("find leds:")
    for led in self.leds:
        print (led)

    return True

""" control led flash """
def flash_led(self):
    led_num = len(self.leds)

    while not Led.quit_flag:
        """ Turn on leds """
        for i in range(led_num):
            """ Set the led brightness value to 1 to turn on the led """
            ret = os.system("echo 1 > %s/brightness" % (self.leds[i]))
            
            if ret != 0:
                print ("Error: Failed to turn on %s" % self.leds[i])

        """ Keep the leds on for 500 ms """
        time.sleep(0.5)

        for i in range(led_num):
            """ Set the led brightness value to 0 to turn off the LED """
            os.system("echo 0 > %s/brightness" % (self.leds[i]))

        """ Keep the leds off for 500 ms """
        time.sleep(0.5)

@classmethod
def stop(cls):
    cls.quit_flag = True

def sig_handle(signum, frame):

print ("ctrl + c ...")

Led.stop()

def usage():

print ("Usage: %s [options]\n"

"Options: \n"

" -v | --version Display version information\n"

" -h | --help Display help\n"

% sys.argv[0])

if name == ' main ':

""" parse parameter """

try:

options, remainder = getopt.getopt(sys.argv[1:], 'vh', ['version', 'help'])

for opt, arg in options:

if opt in ('-v', '--version'):

print ('version: %s' % version)

exit(0)

elif opt in('-h', '--help'):

usage()

exit(0)

except getopt.GetoptError as err:
    print ('ERROR: %s' % err)
    exit(1)

""" Ctrl+c handler """
signal.signal(signal.SIGINT, sig_handle)

led = Led("/sys/class/leds/")

""" enumerate all led """
ret = led.enumerate_led()
""" can not find led """
if not ret:
    print ("can not find led!")
    exit(3)

""" control flash all led """
print ("\\nflash led ...")

led.flash_led()

2.代码上传至开发板

3.运行python文件

4.实际效果

蓝色LED指示灯交替闪烁。。。