產品說明0
配件清單
- 1、PM2.5激光粉塵傳感器V2 x1
- 2、紅外CO2二氧化碳傳感器(0-50000ppm) x1
- 3、DFRobot Bluno M3控制器(兼容Arduino/STM32) x1
- 4、LCD Keypad Shield 按鍵擴展板 x1
許願人： 程老師，坐標魔都，初中信息老師一枚。
我的心願： 籌集xxxx元心願單產品購買返點，為學校5個班級配備空氣檢測裝置套件，檢測空氣質量。
心願故事：
我大魔都是最魅力的時尚中心，最發達的金融中心，最小資的文化中心…延續著過去的輝煌，保持著今天的繁榮，創造著未來的希望!
啥啥都好，吃嘛嘛香，但近幾年來空氣愈發不好，一到冬天，霧霾時常光顧…
作為一枚朝七晚六的老師，經常會忘了看空氣質量指數，有時候上室外課，帶著祖國的花朵們呼吸霧霾的感覺真的是衰爆…於是想，要是能做一個空氣質量檢測裝置，放在家里和教室裡，就能實時檢測數據，提醒家人和學校的師生們：今天有霧霾，出門須謹慎。對北方來說，這個裝置應該是剛需吧。
於是，今年年初的時候，做了一個PM2.5和二氧化碳檢測的裝置，效果還不錯哦。現在終於有機會在心願單上和大家一起分享啦！希望能得到大家的支持！
摘要：
採用Arduino開源硬件，搭配PM2.5空氣質量傳感器和紅外CO2二氧化碳傳感器，製成一個小型的室內空氣質量檢測台。
又到一年一度的冬日魔都霧霾季，2017年的第一個工作日就在這樣一個“中度污染”日子裡到來。這日子沒法過了！
新年第一天上班，你們懂得手上剛好有一個閒置的PM2.5傳感器，一個紅外CO2二氧化碳的傳感器，本著不浪費的小市民心理，打算做一個小應用玩玩。搜刮了一圈桌子，找了一塊Bluno M3和LCD keypad液晶屏。
說明：
Bluno M3並不是一個常見的Arduino板，它是DF基於STM32開發的Arduino兼容板，優點是便宜，管腳資源多；但缺點也很明顯，與一般的Arduino板存在兼容性問題（當然啦，Arduino是8位機，STM32是32位機，有部分不兼容是非常正常的事情）。這邊選擇M3的一個原因是M3有5個UART口，而這PM2.5和紅外傳感器又都是串口設備，對於M3來說是完全夠了的；帶藍牙（教程不含藍牙功能，懶） ；最後就是這個板子放著也是放著~~用UNO，Leonardo，Mega2560等其實也完全沒問題。
LCD keypad雖然佔了很多管腳，但是上面有個PM2.5轉接板的專用接口，省去了我接線的麻煩。
教程：
硬件操作：
紅外二氧化碳用的是雙頭PH2.0，其中一個要改成XH2.54的接頭（用公母頭的杜邦線直插也是可以的，就是最好能固定一下）
這邊選了Bluno M3的Serial1和Serial5兩個串口分別作為PM2.5和CO2的UART通信口，Serial1直接連到的LCD上的PM2.5的接口，所以不用改動，但UART5還是要把排針彎一下的，方便插。
看圖連線
軟件:
在IDE中選擇Bluno M3，選擇對應串口，燒入以下代碼
（注意，Bluno M3的串口是從Serial1開始的，燒錄代碼的時候，為了防止上傳出錯，先不要插PM2.5轉接板，另外，使用UNO，Leonardo的童鞋可以用軟串口來讀取數據，並不一定要Bluno M3的
#include <Arduino.h> #define LENG 31 //0x42 + 31 bytes equal to 32 bytes unsigned char buf[LENG]; unsigned char hexdata[9] = {0xFF, 0x01, 0x86, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79}; //Read the CO2 gas density command /Don\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'t change the order long hi, lo, CO2; int PM2_5Value = 0; //define PM2.5 value of the air detector module -
#include <LiquidCrystal.h> LiquidCrystal lcd(8, 9, 4, 5, 6, 7); // select the pins used on the LCD panel -
-
void setup() { Serial1.begin(9600); //PM2.5 串口1 Serial5.begin(9600); //CO2 串口5 使用UNO和Leonardo的童鞋可以用软串口 Serial1.setTimeout(1500); //设置超时时间为1500毫秒（大于传感器传送数据周期1秒） lcd.begin(16, 2); // LCD 初始化 } -
void loop() { -
//CO2 value Serial5.write(hexdata, 9); -
for (int i = 0, j = 0; i < 9; i++) { if (Serial5.available() > 0) { -
int ch = Serial5.read(); -
if (i == 2) { hi = ch; //High concentration } if (i == 3) { lo = ch; //Low concentration } if (i == 8) { CO2 = hi * 256 + lo; //CO2 concentration } } } -
//PM2.5 -
-
if (Serial1.find(0x42)) { //检测到0x42时，开始读取 Serial1.readBytes(buf, LENG); -
if (buf[0] == 0x4d) { if (checkValue(buf, LENG)) { PM2_5Value = transmitPM2_5(buf); //count PM2.5 value of the air detector module } } } -
// LCD显示 -
static unsigned long OledTimer = millis(); if (millis() - OledTimer >= 1000) { OledTimer = millis(); -
lcd.setCursor(0, 0); // set the LCD cursor position -
lcd.print(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"PM2.5: \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"); lcd.print(PM2_5Value); lcd.println(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\" ug/m3 \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"); lcd.setCursor(0, 1); // set the LCD cursor position lcd.print(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"CO2: \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"); lcd.print(CO2); lcd.print(\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\" PPM \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"); -
} -
} char checkValue(unsigned char *thebuf, char leng) { char receiveflag = 0; int receiveSum = 0; -
for (int i = 0; i < (leng - 2); i++) { receiveSum = receiveSum + thebuf[i]; } receiveSum = receiveSum + 0x42; -
if (receiveSum == ((thebuf[leng - 2] << 8) + thebuf[leng - 1])) //check the Serial1 data { receiveSum = 0; receiveflag = 1; } return receiveflag; } -
//transmit PM Value to PC int transmitPM2_5(unsigned char *thebuf) { int PM2_5Val; PM2_5Val = ((thebuf[5] << 8) + thebuf[6]); //count PM2.5 value of the air detector module return PM2_5Val; } |
上傳成功，等待15s後，PM2.5開始有數據，室內空氣還不錯，就是二氧化碳濃度有點高（如果CO2濃度一上來是65536，點一下復位先。）
魔都當天的PM2.5濃度如下圖，上午從190掉到180了。（昨天上午）
拿到窗邊，5秒不到CO2是下來了，但這PM2.5，看著好想搬家啊！
總結：PM的精度還闊以，CO2除了有點貴外沒啥缺點，哈幾口氣差不多能到30000多，NDIR的檢測方式在響應速度上確實有點慢，雖然官網給了90s，但還是有點不能忍。
