RT-Thread-[第3期空气质量分析仪]第2周作业RT-Thread问答社区

[第3期空气质量分析仪]第2周作业

发布于 2019-10-23 14:40:28 浏览：809 订阅该版

**任务1：**

temp_humi_th.c
```#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>

#include "temp_humi.h"
#include "temp_humi_th.h"

static rt_thread_t temp_humi_tid = RT_NULL;

static void temp_humi_entry(void *parameter)
{
 float humidity, temperature;
 
 while(1){
 aht10_read_humi(&humidity);
 aht10_read_temp(&temperature);
 
 rt_kprintf("read aht10 sensor humidity : %d.%d %% ", (int)humidity, (int)(humidity * 10) % 10);
 if( temperature >= 0 )
 {
 rt_kprintf("read aht10 sensor temperature: %d.%d°C ", (int)temperature, (int)(temperature * 10) % 10);
 }
 else
 {
 rt_kprintf("read aht10 sensor temperature: %d.%d°C ", (int)temperature, (int)(-temperature * 10) % 10);
 }
 rt_thread_mdelay(1000);
 }
}

static void hook_of_scheduler(struct rt_thread* from, struct rt_thread* to)
{
 rt_kprintf("from: %s --> to: %s ", from->name , to->name);
}

void temp_humi_init(void)
{
    const char *i2c_bus_name = "i2c4";
    aht10_hw_init(i2c_bus_name);
    
    // rt_scheduler_sethook(hook_of_scheduler);
    
    temp_humi_tid = rt_thread_create("temp_humi_tid",
                                     temp_humi_entry, RT_NULL,
                                     1024,
                                     RT_MAIN_THREAD_PRIORITY - 1,
                                     10
                                     );
    if(temp_humi_tid != RT_NULL)
        rt_thread_startup(temp_humi_tid);

}```

**任务2：**

GP2Y原理图：

ILED 接 MCU PB8（GPIO），K_LED 接 MCU PC2（ADC1_CH3）。

GP2Y 模块上的 滑动电阻器用于调节放大电路的灵敏度，ADC 采不到数据可以调节滑动电阻试试。

pm25.c
```#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>

#include "pm25.h"

#define ADC_DEV_NAME "adc1" /* ADC 设备名称 */
#define ADC_DEV_CHANNEL 3 /* ADC 通道 */
#define REFER_VOLTAGE 330 /* 参考电压 3.3V,数据精度乘以100保留2位小数*/
#define CONVERT_BITS (1 << 12) /* 转换位数为12位 */
#define RATIO 0.2 
#define NO_DUST_VOLTAGE 400

#define ILED_PIN    GET_PIN(B, 8)

rt_adc_device_t adc_dev;            /* ADC 设备句柄 */

void gp2y_hw_init()
{
    rt_pin_mode(ILED_PIN, PIN_MODE_OUTPUT);
    rt_pin_write(ILED_PIN, PIN_LOW);
    
    
    /* 查找设备 */
    adc_dev = (rt_adc_device_t)rt_device_find(ADC_DEV_NAME);

if (adc_dev == RT_NULL)
 {
 rt_kprintf("adc sample run failed! can't find %s device! ", ADC_DEV_NAME);
 }
 /* 使能设备 */
 rt_adc_enable(adc_dev, ADC_DEV_CHANNEL);
}

float gp2y_read_pm25()
{
 rt_uint32_t value, vol;
 float voltage,dens;
 
 rt_pin_write(ILED_PIN, PIN_HIGH);
 rt_hw_us_delay(500);
 
 /* 读取采样值 */
 value = rt_adc_read(adc_dev, ADC_DEV_CHANNEL);
 
 rt_pin_write(ILED_PIN, PIN_LOW);
// rt_thread_mdelay(5);
 
 
 
 /* 转换为对应电压值 */
 voltage = value * (3300 / 4096.0) * 11;
 vol = value * REFER_VOLTAGE / CONVERT_BITS * 11;
 rt_kprintf("the voltage is :%d.%02d ", vol / 100, vol % 100);
 
 if(voltage >= NO_DUST_VOLTAGE){
 dens = (voltage - NO_DUST_VOLTAGE) * RATIO;
 return dens;
 }
 else{
 return 0;
 }

}
```

pm25_th.c
```#include <rtthread.h>
#include <rtdevice.h>
#include <board.h>

#include "pm25.h"

#include "pm25_th.h"

static rt_thread_t pm25_tid = RT_NULL;

void pm25_entry(void *parameter)
{
 float dens = 0;
 
 while(1){
 dens = gp2y_read_pm25();
 rt_kprintf("dens: %d.%d ug/m3 ", (int)dens, (int)(dens * 10) % 10);
 
 rt_thread_mdelay(1000);
 }

}

void pm25_init()
{
    gp2y_hw_init();
    pm25_tid = rt_thread_create("pm25_tid",
                                pm25_entry, RT_NULL,
                                1024,
                                RT_MAIN_THREAD_PRIORITY - 1,
                                20
                                );
    if(pm25_tid != RT_NULL)
        rt_thread_startup(pm25_tid);
}```

本周主要学习线程的创建，具体原理应该是 arm 的 PendSV 软中断吧，还不是很懂，准备把 Cortex 权威指南读一读，读完再来写。
**
**rt_thread_create() 用于创建线程，线程的优先级和轮转时间应该是比较重要的参数，关系到线程的运行。

![Annotation 2019-10-23 142808.png](https://oss-club.rt-thread.org/uploads/201910/23/142818d0264bgji9jj9ss4.png)