RT-Thread-空气质量分析仪]第1周作业RT-Thread问答社区

空气质量分析仪]第1周作业

发布于 2019-10-18 00:55:06 浏览：944 订阅该版

* 本帖最后由 韧明 于 2019-10-18 01:02 编辑 *

一，制作BSP
    采用STM32F407 Discovery Board, 自带BSP，无需制作。

![bsp.png](/uploads/201910/18/004356r43xzkk4b9891m04.png)
二，LED配置：
    查询了原理图上的LED管脚，根据RTT的API配置了LED，代码如下：
    led_alert.c:

```#include "led_alert.h"

void led_init(void){
    rt_pin_mode(LED0_PIN, PIN_MODE_OUTPUT);
    rt_pin_write(LED0_PIN, PIN_LOW); // LED off by default 
    rt_pin_mode(LED1_PIN, PIN_MODE_OUTPUT);
    rt_pin_write(LED1_PIN, PIN_LOW); // LED off by default 
}

void led_on(rt_int32_t pin){
    rt_pin_write(pin, PIN_HIGH);
}

void led_off(rt_int32_t pin){
    rt_pin_write(pin, PIN_LOW); 
}

void led_blink(rt_int32_t pin){
    led_on(pin);
    rt_thread_mdelay(200);
    led_off(pin);
    rt_thread_mdelay(200);
}```    led_alert.h:
```#ifndef LED_ALERT_H
#define LED_ALERT_H

#include "rtthread.h"
#include "drv_gpio.h"

#define LED1_PIN GET_PIN(D, 12) // Green LED 
/* defined the LED0 pin: PD14 */
#define LED0_PIN GET_PIN(D, 14)

void led_init(void);
void led_on(rt_int32_t pin);
void led_off(rt_int32_t pin);
void led_blink(rt_int32_t pin);

#endif ```三，按键
    根据BSP自带的drv_gpio.c和头文件简单写了下：
```#ifndef KEY_H
#define KEY_H
#include "rtthread.h"
#include "drv_gpio.h"
#include "led_alert.h"

void key_init(void);
void key_cb(void * args);

#endif```
```#include "key.h"

#define KEY0_PIN  GET_PIN(A, 0)

void key_cb(void * args){
    if( rt_pin_read(KEY0_PIN) == PIN_LOW ){
        led_on(LED1_PIN);
    }else{
        led_off(LED1_PIN);
    }
}

void key_init(void){
    rt_pin_mode(KEY0_PIN, PIN_MODE_INPUT_PULLUP);
    rt_pin_attach_irq(KEY0_PIN, PIN_IRQ_MODE_RISING_FALLING, key_cb, RT_NULL);
    rt_pin_irq_enable(KEY0_PIN, PIN_IRQ_ENABLE);
}```四，温湿度传感器SHT31
     这个我买错了，不过也就将错就错了。用env工具配置了SHT2x的驱动，I2C地址改为0x44，然后改了I2C的通信字节和计算公式，然后就可以了。当然，现在做得比较简单，也没有加CRC校验，如果要做成正式可用的驱动，还得多改改。温度应该没问题，相对湿度一直是100%，难道是上海这边比较潮湿？
    修改sht20.c代码如下：
```static float read_hw_humidity(sht20_device_t dev)
{
    rt_uint8_t temp[6] = {0x24, 0x0B} ;
    float current_humi = 0.0; //The data is error with missing measurement. 
    rt_err_t result;

RT_ASSERT(dev);

result = rt_mutex_take(dev->lock, RT_WAITING_FOREVER);
    if (result == RT_EOK)
    {
        rt_i2c_master_send(dev->i2c, SHT20_ADDR, RT_I2C_WR, temp, 2);
        rt_i2c_master_recv(dev->i2c, SHT20_ADDR, RT_I2C_RD, temp, 6);
        rt_kprintf("%x, %x, %x, %x, %x, %x  <br>", temp[0], temp[1], temp[2], temp[3], temp[4], temp[5]);       
        current_humi = (temp[4] | temp[3] << 8) * 0.0015259022 ; ; //sensor humidity convert to reality
    }
    else
    {
        LOG_E("The sht20 could not respond relative humidity measurement at this time. Please try again");
    }
    rt_mutex_release(dev->lock);

return current_humi;
}

static float read_hw_temperature(sht20_device_t dev)
{
    rt_uint8_t temp[6] = {0x24, 0x0B} ;
    float current_temp = -46.85; //The data is error with missing measurement. 
    rt_err_t result;

RT_ASSERT(dev);

result = rt_mutex_take(dev->lock, RT_WAITING_FOREVER);
    if (result == RT_EOK)
    {
        rt_i2c_master_send(dev->i2c, SHT20_ADDR, RT_I2C_WR, temp, 2);
        rt_i2c_master_recv(dev->i2c, SHT20_ADDR, RT_I2C_RD, temp, 6);
        rt_kprintf("%x, %x, %x, %x, %x, %x  <br>", temp[0], temp[1], temp[2], temp[3], temp[4], temp[5]);
        current_temp = -45.0 + (temp[1] | temp[0] << 8) * 175.0 / (0xFFFF - 1) ; //sensor temperature convert to reality
    }
    else
    {
        LOG_E("The sht20 could not respond temperature measurement at this time. Please try again");
    }
    rt_mutex_release(dev->lock);

return current_temp;
}```![sht31.png](/uploads/201910/18/005346kkfuncwnfzk9snne.png)
    好，作业已完成，睡觉！