【单片机】PMS5003，PM2.5传感器数据读取处理_pms5003是如何计算值的,怎样证明它测出pm2.5浓度的准确性

传感器介绍

PMS5003是一款基于激光散射原理的数字式通用颗粒物浓度传感器,可连续采集
并计算单位体积内空气中不同粒径的悬浮颗粒物个数,即颗粒物浓度分布,进而
换算成为质量浓度,并以通用数字接口形式输出。本传感器可入各种与空气中
悬浮颗粒物浓度相关的仪器仪表或环境改善设备,为其提供及时准确的浓度数
据。

数据处理

读取的数据：

解析pm2.5的代码

逻辑是：
1、初始化串口和定时器10ms中断
2、循环读取一帧数据到rev_pm25_bufferdata
3、在主函数解析数据rev_pm25_bufferdata
4、最终的pm2.5数值就是pm25_value

使用pm25_value 的数据即可。

#include "sys.h"
#include "delay.h"
#include "usart.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "led.h"
#include "timer.h"


char rev_pm25_bufferdata[50];
char rev_pm25_data_cnt = 0;
char rev_pm25_flag = 0;
char rev_pm25_timercnt = 0;
char rev_pm25_sucess = 0;
uint32_t pm25_value = 0;
uint32_t pm25_verify = 0;
unsigned char pm25_verify_cnt = 0;

int main(void) {

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    delay_init();
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
    GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);

    delay_ms(500);
    uart_init(9600);

    TIM4_Int_Init(99, 7199);                                     /* 10Khz的计数频率，计数到50为10ms */
    TIM_Cmd(TIM4, ENABLE);                                        /* 使能TIMx  开始计时 */


    while (1) {

        delay_ms(5);

        if (rev_pm25_sucess == 1) {
            rev_pm25_sucess = 0;

            if ((rev_pm25_bufferdata[0] == 0x42) && (rev_pm25_bufferdata[1] == 0x4d)) {
                pm25_verify = 0;
                for (pm25_verify_cnt = 0; pm25_verify_cnt < 30; pm25_verify_cnt++) {
                    pm25_verify += rev_pm25_bufferdata[pm25_verify_cnt];
                }
                if (pm25_verify == (rev_pm25_bufferdata[30] * 256 + rev_pm25_bufferdata[31])) {
                    pm25_value = rev_pm25_bufferdata[6] * 256 + rev_pm25_bufferdata[7];
                }
            }
        }
    }
}


// 10ms
void TIM4_IRQHandler(void)                                    /* TIM4中断 */
{
    if (TIM_GetITStatus(TIM4, TIM_IT_Update) != RESET)  /* 检查TIM4更新中断发生与否 */
    {
        TIM_ClearITPendingBit(TIM4, TIM_IT_Update);   /* 清除TIM4更新中断标志 */
        //10ms一帧
        if (rev_pm25_flag == 1) {
            rev_pm25_timercnt++;
        }
        if (rev_pm25_timercnt >= 4) {
            rev_pm25_timercnt = 0;
            rev_pm25_flag = 0;
            //数据处理标志
            rev_pm25_sucess = 1;
        }

    }
}


//A9模块
void USART1_IRQHandler(void)                                                                  /* 串口1中断服务程序 */
{
    u8 receiveData;
    if (USART_GetITStatus(USART1, USART_IT_RXNE) !=
        RESET)                              /* 接收中断(接收到的数据必须是0x0d 0x0a结尾) */
    {
        receiveData = USART_ReceiveData(USART1);                                      /* 读取接收到的数据 */

        if (rev_pm25_flag == 0) {
            rev_pm25_data_cnt = 0;
            rev_pm25_bufferdata[rev_pm25_data_cnt++] = receiveData;
            rev_pm25_flag = 1;
        } else if (rev_pm25_flag == 1) {
            rev_pm25_bufferdata[rev_pm25_data_cnt++] = receiveData;
            if (rev_pm25_data_cnt >= 50) {
                rev_pm25_data_cnt = 0;
            }
        }
    }
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99

帮助、问询

https://docs.qq.com/sheet/DUEdqZ2lmbmR6UVdU?tab=BB08J2
1