树莓派blink，让小灯闪起来
话说，突然想起吃灰长达7个月之久的树莓派。当初购买回来之后，折腾装系统，折腾联网，折腾无线网卡，折腾打印服务器以及文件服务器等。
现在回想起来，甚至都忘记了当时具体做了些什么，如何做的。看来写日志还是有必要的，像雷锋同志学习。发到狗趴上(Godpub.com) 没准能吸引点人气，不能让二叔孤军作战是吧。
好了，言归正传。
硬件接线
GPIO 0(编号11的排针）串220欧电阻后LED正极。
0V (编号6的排针）接LED负极。
GPIO图暂略。
软件部分
因为之前无线网卡啥的都是设置好的，所以拿来上电，putty登录。
登录目录下有个wiringPi/目录（说实话，我忘记了这个是否是自带的，还是我装上的，权且当作自带的吧）
进入到示例目录：
cd wiringPi/examples/
里边保存有一些代码示例：
blink.sh 这个是shell脚本控制小灯的例子。
blink.c 这个是C语言代码控制小灯的例子。
（其它还有8个小灯，串口等例子，这里就不多说了）
blink.sh内容如下：#!/bin/sh
#
# blink.sh:
# Standard "blink" program in wiringPi. Blinks an LED connected
# to the first GPIO pin.
#
# Copyright (c) 2012-2013 Gordon Henderson. <projects@drogon.net>
#######################################################################
# This file is part of wiringPi:
# https://projects.drogon.net/raspberry-pi/wiringpi/
#
# wiringPi is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# wiringPi is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with wiringPi.If not, see <http://www.gnu.org/licenses/>.
#######################################################################
# LED Pin - wiringPi pin 0 is BCM_GPIO 17.
<b><font color="#ff0000">LED=0</font></b>
gpio mode $PIN out
while true; do
gpio write $PIN 1
sleep 0.5
gpio write $PIN 0
sleep 0.5
done
执行之（sh blink.sh），我们会得到提示的错误信息
Usage: gpio mode pin mode
Usage: gpio write pin value
Usage: gpio write pin value
...
为什么会这样呢？回头看文件中我们红色加粗的那行，里边定义了一个变量LED，但是调用命令的时候，使用的变量却是PIN！
话说，写这个例子的人也太不负责了，强烈谴责！
把LED=0改成PIN=0，保存执行。
小灯是不是闪了起来？简单吧？
接下来看blink.c，内容如下：
/*
* blink.c:
* Standard "blink" program in wiringPi. Blinks an LED connected
* to the first GPIO pin.
*
* Copyright (c) 2012-2013 Gordon Henderson. <projects@drogon.net>
***********************************************************************
* This file is part of wiringPi:
* https://projects.drogon.net/raspberry-pi/wiringpi/
*
* wiringPi is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* wiringPi is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with wiringPi.If not, see <http://www.gnu.org/licenses/>.
***********************************************************************
*/
#include <stdio.h>
#include <wiringPi.h>
// LED Pin - wiringPi pin 0 is BCM_GPIO 17.
#define LED 0
int main (void)
{
printf ("Raspberry Pi blink\n") ;
wiringPiSetup () ;
pinMode (LED, OUTPUT) ;
for (;;)
{
digitalWrite (LED, HIGH) ;// On
delay (500) ; // mS
digitalWrite (LED, LOW) ; // Off
delay (500) ;
}
return 0 ;
}是不是很熟悉，简直和Arduino的一样。
编译并执行：
make blink
sudo ./blink熟悉的小灯闪闪又开始了。
PS:
Ctrl+c 停掉程序。根据停掉的时机，小灯会处于常亮或者常灭状态。
结束语
太晚了，就写这么多了。
原创啊，转载请保留狗趴(Godpub.com)链接。
既没有接线图又没有效果图，强烈BS
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