用之前的温湿度模块和iot平台的经验

引脚口使用 gpioB29 也就是简单的一根线进行连接,请搭配本人其他文章[配套使用

dht11drv.c

#include<linux/module.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <asm/mach-types.h>
#include <linux/gpio.h>
#include <asm/gpio.h>
#include <asm/delay.h>
#include <linux/clk.h>
#include <mach/gpio.h>
#include <mach/soc.h>
#include <mach/platform.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/errno.h>
#include <linux/serio.h>
#include <linux/wait.h>
#include <linux/cdev.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <mach/gpio.h>
#include <linux/gpio.h>#define CFG_IO_X6818_Humity (PAD_GPIO_B + 29)static struct class *dht11drv_class;
static struct class_device	*dht11drv_class_dev;volatile unsigned long *gpbcon;
volatile unsigned long *gpbdat;int data_in(void) {gpio_direction_input(CFG_IO_X6818_Humity);return gpio_get_value(CFG_IO_X6818_Humity);
}/*************************************************
*管教设置为输出
*************************************************/
void data_out(int data) {gpio_direction_output(CFG_IO_X6818_Humity, data);
}void DHT11_Rst(void)	   
{                 data_out(0); 	//SET OUTPUTmdelay(20);//拉低至少18msdata_out(1); 	//DQ=1 udelay(30);     	//主机拉高20~40us
}u8 DHT11_Check(void) 	   
{   u8 retry=0;while (data_in()&&retry<100)//DHT11会拉低40~80us{retry++;udelay(1);};	 if(retry>=100)return 1;else retry=0;while (!data_in()&&retry<100)//DHT11拉低后会再次拉高40~80us{retry++;udelay(1);};if(retry>=100)return 1;	    return 0;
}u8 DHT11_Read_Bit(void) 			 
{u8 retry=0;while(data_in()&&retry<100)//等待变为低电平{retry++;udelay(1);}retry=0;while(!data_in()&&retry<100)//等待变高电平{retry++;udelay(1);}udelay(40);//等待40usif(data_in())return 1;else return 0;		   
}u8 DHT11_Read_Byte(void)    
{        u8 i,dat;dat=0;for (i=0;i<8;i++) {dat<<=1; dat|=DHT11_Read_Bit();}						    return dat;
}u8 DHT11_Read_Data(u8 *temp,u8 *humi)    
{        u8 buf[5];u8 i;DHT11_Rst();if(DHT11_Check()==0){for(i=0;i<5;i++)//读取40位数据{buf[i]=DHT11_Read_Byte();}if((buf[0]+buf[1]+buf[2]+buf[3])==buf[4]){*humi=buf[0];*temp=buf[2];}}else return 1;return 0;	    
}static int second_drv_open(struct inode *inode, struct file *file)
{//gpio_direction_input(CFG_IO_X6818_Humity);return 0;
}ssize_t second_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{/* 返回4个引脚的电平 */unsigned int dht11_vals[2];u8 temperature; 		u8 humidity;  int i ;for (i = 0;i<15;i++){DHT11_Read_Data(&temperature,&humidity);mdelay(2000);printk("the tem is %d,hum is %d\n",temperature,humidity);}DHT11_Read_Data(&temperature,&humidity);printk("the tem is %d,hum is %d\n",temperature,humidity);mdelay(2000);dht11_vals[0] = temperature;dht11_vals[1] = humidity;copy_to_user(buf, dht11_vals, sizeof(dht11_vals));return sizeof(dht11_vals);
}static struct file_operations sencod_drv_fops = {.owner  =   THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */.open   =   second_drv_open,     .read	=	second_drv_read,	   
};int major;
static int second_drv_init(void)
{major = register_chrdev(0, "dht11_drv", &sencod_drv_fops);dht11drv_class = class_create(THIS_MODULE, "dht11_drv");dht11drv_class_dev = device_create(dht11drv_class, NULL, MKDEV(major, 0), NULL, "dht11"); /* /dev/buttons */return 0;
}static void second_drv_exit(void)
{unregister_chrdev(major, "dht11_drv");device_unregister(dht11drv_class_dev);class_destroy(dht11drv_class);return 0;
}module_init(second_drv_init);module_exit(second_drv_exit);MODULE_LICENSE("GPL");

app程序:dht11test.c

#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/termios.h>
int main()
{int fd;int ret ;unsigned int dht11_vals[2];fd = open("/dev/dht11", 0);if (fd < 0){printf("can't open!\n");}read(fd, dht11_vals, sizeof(dht11_vals));printf("end the tem is %d,hum is %d\n",dht11_vals[0],dht11_vals[1]);close(fd);return 0;
}

加上Makefile 做出来的驱动

#内核要提前编译好
KERN_DIR = /home/scholar/Desktop/6818GEC/kernel
#-C 是转到后面的目录'$(KERN_DIR)',使用这个目录下面的 Makefile 编译
#M是指当前目标是什么
#moudule 是指目标all:make -C $(KERN_DIR) M=`pwd` modules clean:make -C $(KERN_DIR) M=`pwd` modules cleanrm -rf modules.orderobj-m	+= dht11drv.o

修改 mqtt的代码,对驱动里的数值进行读取
mqtt_demo中 修改的代码

int main(void) {//char *strBuf=(char*)malloc(40);//FILE *fp = fopen("/sys/class/leds/led2/brightness","r");//fgets(strBuf, sizeof(strBuf),fp);// 进行温湿度的检测时间可能会有10sint fd;unsigned int dht11_vals[2];fd = open("/dev/dht11", 0);read(fd, dht11_vals, sizeof(dht11_vals));char buf[1000];char * A="Battery";//属性服务char * B="temperature";//属性名称int * C= dht11_vals[0];char * D="humidity";int * E= dht11_vals[1];sprintf(buf,"{\"services\":[{\"service_id\":\"%s\",\"properties\":{\"%s\":\"%d\",\"%s\":\"%d\"}}]}\0",A,B,C,D,E);int ret = mqtt_connect();if (ret != 0) {printf("connect failed, result %d\n", ret);}time_sleep(3000);//subscribechar *cmd_topic = combine_strings(3, "$oc/devices/", username, "/sys/commands/#");ret = mqtt_subscribe(cmd_topic);free(cmd_topic);cmd_topic = NULL;if (ret < 0) {printf("subscribe topic error, result %d\n", ret);}time_sleep(1000);//publish datachar *payload=buf;char *report_topic = combine_strings(3, "$oc/devices/", username, "/sys/properties/report");ret = mqtt_publish(report_topic, payload);free(report_topic);report_topic = NULL;if (ret < 0) {printf("publish data error, result %d\n", ret);}while(1) {time_sleep(1000);}return 0;return 0;
}