原创【电子DIY设计】+真甲醛检测仪

 2023-12-31 00:37  1311 9 6 分类: 智能硬件

项目背景：甲醛在生活也比较常见：新装修的公寓，不知名的家居，新装修的房子以及吸烟的密闭环境，你没有听错，吸烟过程有大量甲醛，甲醛严重超标。故需要DIY甲醛数显检测，检测时间短，反应快：进口甲醛传感器一致性很好，精度高，sensirion甲醛传感器SFA30，Arduino程序代码：Arduino UNO 驱动OLED实时显示甲醛传感器相关参数：甲醛浓度、温度、湿度，ws2812试试通过颜色确定当前环境中甲醛浓度等级

甲醛相关资料可参考抖音老爸评测中吸烟仓中甲醛浓度，或参考中国知网：吸烟烟雾中的甲醛、室内香烟、电子烟释放甲醛和VOCs的散发特征及健康风险分析等文章

sensirion甲醛传感器SFA30，甲醛传感器一般采用电化学原理，利用甲醛与催化剂作用产生微弱电压信号，经过运放处理后将微弱信号放大然后根据建立模型（湿度、温度补偿）得到甲醛浓度,本教程使用的是sensirion的SFA30甲醛传感器

甲醛传感器原理：

传感器模型框架图：

项目实现：基于Arduino平台搭建甲醛传感器实时显示、指示、读取数据的检测仪，真实检查环境中的甲醛浓度，专业甲醛检测仪动辄上万元，对于普通家庭很难承担，sensirion甲醛传感器SFA30基于电化学原理，通过半透膜筛选甲醛分子，真真切切检测环境中甲醛浓度。

项目原理图：

PCB图：

3D渲染图：

实物图：

视频介绍：

代码附件：

#include <Arduino.h>
#include <SensirionUartSfa3x.h>
#define SENSOR_SERIAL_INTERFACE Serial
SensirionUartSfa3x sfa3x;
#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
#include <avr/power.h>
#endif
#define PIN 11
Adafruit_NeoPixel strip = Adafruit_NeoPixel(60, PIN, NEO_GRB + NEO_KHZ800);
#include "font.h"
int16_t hcho;
int16_t relativeHumidity;
int16_t temperature;
int SFA30_date=0;
uint16_t error;
int scl=A5;//定义OLEDSCL为A1引脚
int sda=A4;//定义OLEDSCL为A0引脚
int res=10;//定义OLE DRES为10引脚(IIC通信可不用设置)
#define OLED_SCLK_Clr() digitalWrite(scl,LOW)//SCL
#define OLED_SCLK_Set() digitalWrite(scl,HIGH)
#define OLED_SDIN_Clr() digitalWrite(sda,LOW)//SDA
#define OLED_SDIN_Set() digitalWrite(sda,HIGH)
#define OLED_RST_Clr() digitalWrite(res,LOW)//RES 注：此引脚是为了配合SPI驱动模块改成I2C驱动模块使用的（改装的话必须接），如果买的是I2C模块，请忽略此引脚。
#define OLED_RST_Set() digitalWrite(res,HIGH)
#define OLED_CMD 0 //写命令
#define OLED_DATA 1 //写数据
uint8_t OLED_GRAM[128][8];//将要显示的缓存内容
void setup()
{
pinMode(2, OUTPUT);pinMode(3, OUTPUT);//SFA30传感器供电引脚使能
digitalWrite(3, HIGH);digitalWrite(2, LOW);//SFA30传感器供电输出
pinMode(A3, OUTPUT);pinMode(A2, OUTPUT); //OLED供电引脚使能
digitalWrite(A3,LOW); digitalWrite(A2,HIGH);//OLED供电输出
OLED_Init();//OLED初始化
OLED_ColorTurn(0);//0正常显示 1反色显示
OLED_DisplayTurn(0);//0正常显示 1翻转180度显示
SENSOR_SERIAL_INTERFACE.begin(115200);
while (!SENSOR_SERIAL_INTERFACE) {delay(100);}
sfa3x.begin(SENSOR_SERIAL_INTERFACE);
sfa3x.deviceReset();//SFA30传感器复位
sfa3x.startContinuousMeasurement();//SFA30传感器开始测试
//WS2812驱动
#if defined (__AVR_ATtiny85__)
if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
#endif
// End of trinket special code
strip.begin();
strip.setBrightness(50);
strip.show(); // Initialize all pixels to 'off'
//WS2812驱动
}
void loop()
{
while(1)
{
sfa3x.readMeasuredValuesOutputFormat2(hcho, relativeHumidity,temperature);//获取SFA30传感器数据
//OLED_Clear();
OLED_ShowString(0,0,"T:",16);OLED_ShowNum(40,0,temperature/200,2,16); OLED_ShowString(56,0,".",16);OLED_ShowNum(64,0,temperature%200,2,16);OLED_DrawCircle(82,4,1);OLED_ShowString(86,0,"C",16);
OLED_ShowString(0,16,"H:",16);OLED_ShowNum(40,16,relativeHumidity/100,2,16); OLED_ShowString(56,16,".",16);OLED_ShowNum(64,16,relativeHumidity%100,2,16); OLED_ShowString(82,16,"%",16);
OLED_ShowString(0,32,"HCHO:",16);OLED_ShowNum(40,32,hcho/5,3,16);OLED_ShowString(66,32,"ppb",16);
OLED_ShowString(0,48,"date:",16);OLED_ShowNum(40,48,SFA30_date,3,16);
OLED_Refresh();
delay(50);SFA30_date++;
if(hcho<307)
{colorWipe(strip.Color(0, 255, 0), 50); }// Green
else if(hcho<615)
{colorWipe(strip.Color(0, 0, 255), 50); }// Green
else if(hcho<615)
{colorWipe(strip.Color(255, 0, 0), 50); }// Red
}
}
//反显函数
void OLED_ColorTurn(uint8_t i)
{
if(!i) OLED_WR_Byte(0xA6,OLED_CMD);//正常显示
else OLED_WR_Byte(0xA7,OLED_CMD);//反色显示
}
//屏幕旋转180度
void OLED_DisplayTurn(uint8_t i)
{
if(i==0)
{
OLED_WR_Byte(0xC8,OLED_CMD);//正常显示
OLED_WR_Byte(0xA1,OLED_CMD);
}
else
{
OLED_WR_Byte(0xC0,OLED_CMD);//反转显示
OLED_WR_Byte(0xA0,OLED_CMD);
}
}
//起始信号
void I2C_Start(void)
{
OLED_SDIN_Set();
OLED_SCLK_Set();
OLED_SDIN_Clr();
OLED_SCLK_Clr();
}
//结束信号
void I2C_Stop(void)
{
OLED_SCLK_Set();
OLED_SDIN_Clr();
OLED_SDIN_Set();
}
//等待信号响应
void I2C_WaitAck(void) //测数据信号的电平
{
OLED_SCLK_Set();
OLED_SCLK_Clr();
}
//写入一个字节
void Send_Byte(uint8_t dat)
{
uint8_t i;
for(i=0;i<8;i++)
{
OLED_SCLK_Clr();//将时钟信号设置为低电平
if(dat&0x80)//将dat的8位从最高位依次写入
{
OLED_SDIN_Set();
}
else
{
OLED_SDIN_Clr();
}
OLED_SCLK_Set();//将时钟信号设置为高电平
OLED_SCLK_Clr();//将时钟信号设置为低电平
dat<<=1;
}
}
//发送一个字节
//向SSD1306写入一个字节。
//mode:数据/命令标志 0,表示命令;1,表示数据;
void OLED_WR_Byte(uint8_t dat,uint8_t mode)
{
I2C_Start();
Send_Byte(0x78);
I2C_WaitAck();
if(mode){Send_Byte(0x40);}
else{Send_Byte(0x00);}
I2C_WaitAck();
Send_Byte(dat);
I2C_WaitAck();
I2C_Stop();
}
//更新显存到OLED
void OLED_Refresh(void)
{
uint8_t i,n;
for(i=0;i<8;i++)
{
OLED_WR_Byte(0xb0+i,OLED_CMD); //设置行起始地址
OLED_WR_Byte(0x00,OLED_CMD); //设置低列起始地址
OLED_WR_Byte(0x10,OLED_CMD); //设置高列起始地址
for(n=0;n<128;n++)
OLED_WR_Byte(OLED_GRAM[n][i],OLED_DATA);
}
}
//清屏函数
void OLED_Clear(void)
{
uint8_t i,n;
for(i=0;i<8;i++)
{
for(n=0;n<128;n++)
{
OLED_GRAM[n][i]=0;//清除所有数据
}
}
OLED_Refresh();//更新显示
}
//画点
//x:0~127
//y:0~63
void OLED_DrawPoint(uint8_t x,uint8_t y)
{
uint8_t i,m,n;
i=y/8;
m=y%8;
n=1<<m;
OLED_GRAM[x][i]|=n;
}
//清除一个点
//x:0~127
//y:0~63
void OLED_ClearPoint(uint8_t x,uint8_t y)
{
uint8_t i,m,n;
i=y/8;
m=y%8;
n=1<<m;
OLED_GRAM[x][i]=~OLED_GRAM[x][i];
OLED_GRAM[x][i]|=n;
OLED_GRAM[x][i]=~OLED_GRAM[x][i];
}
//画线
//x:0~128
//y:0~64
void OLED_DrawLine(uint8_t x1,uint8_t y1,uint8_t x2,uint8_t y2)
{
uint8_t i,k,k1,k2,y0;
if(x1==x2) //画竖线
{
for(i=0;i<(y2-y1);i++)
{
OLED_DrawPoint(x1,y1+i);
}
}
else if(y1==y2) //画横线
{
for(i=0;i<(x2-x1);i++)
{
OLED_DrawPoint(x1+i,y1);
}
}
else //画斜线
{
k1=y2-y1;
k2=x2-x1;
k=k1*10/k2;
for(i=0;i<(x2-x1);i++)
{
OLED_DrawPoint(x1+i,y1+i*k/10);
}
}
}
//x,y:圆心坐标
//r:圆的半径
void OLED_DrawCircle(uint8_t x,uint8_t y,uint8_t r)
{
int a, b,num;
a = 0;
b = r;
while(2 * b * b >= r * r)
{
OLED_DrawPoint(x + a, y - b);
OLED_DrawPoint(x - a, y - b);
OLED_DrawPoint(x - a, y + b);
OLED_DrawPoint(x + a, y + b);
OLED_DrawPoint(x + b, y + a);
OLED_DrawPoint(x + b, y - a);
OLED_DrawPoint(x - b, y - a);
OLED_DrawPoint(x - b, y + a);
a++;
num = (a * a + b * b) - r*r;//计算画的点离圆心的距离
if(num > 0)
{
b--;
a--;
}
}
}
//在指定位置显示一个字符,包括部分字符
//x:0~127
//y:0~63
//size:选择字体 12/16/24
//取模方式逐列式
void OLED_ShowChar(uint8_t x,uint8_t y,const char chr,uint8_t size1)
{
uint8_t i,m,temp,size2,chr1;
uint8_t y0=y;
size2=(size1/8+((size1%8)?1:0))*(size1/2); //得到字体一个字符对应点阵集所占的字节数
chr1=chr-' '; //计算偏移后的值
for(i=0;i<size2;i++)
{
if(size1==12)
{
temp=pgm_read_byte(&asc2_1206[chr1][i]);
} //调用1206字体
else if(size1==16)
{
temp=pgm_read_byte(&asc2_1608[chr1][i]);
} //调用1608字体
else if(size1==24)
{
temp=pgm_read_byte(&asc2_2412[chr1][i]);
} //调用2412字体
else return;
for(m=0;m<8;m++) //写入数据
{
if(temp&0x80)OLED_DrawPoint(x,y);
else OLED_ClearPoint(x,y);
temp<<=1;
y++;
if((y-y0)==size1)
{
y=y0;
x++;
break;
}
}
}
}
//显示字符串
//x,y:起点坐标
//size1:字体大小
//*chr:字符串起始地址
void OLED_ShowString(uint8_t x,uint8_t y,const char *chr,uint8_t size1)
{
while((*chr>=' ')&&(*chr<='~'))//判断是不是非法字符!
{
OLED_ShowChar(x,y,*chr,size1);
x+=size1/2;
if(x>128-size1/2) //换行
{
x=0;
y+=size1;
}
chr++;
}
}
//m^n
u32 OLED_Pow(uint8_t m,uint8_t n)
{
u32 result=1;
while(n--)
{
result*=m;
}
return result;
}
////显示2个数字
////x,y :起点坐标
////len :数字的位数
////size:字体大小
void OLED_ShowNum(uint8_t x,uint8_t y,int num,uint8_t len,uint8_t size1)
{
uint8_t t,temp;
for(t=0;t<len;t++)
{
temp=(num/OLED_Pow(10,len-t-1))%10;
if(temp==0)
{
OLED_ShowChar(x+(size1/2)*t,y,'0',size1);
}
else
{
OLED_ShowChar(x+(size1/2)*t,y,temp+'0',size1);
}
}
}
//显示汉字
//x,y:起点坐标
//num:汉字对应的序号
//取模方式列行式
void OLED_ShowChinese(uint8_t x,uint8_t y,const uint8_t num,uint8_t size1)
{
uint8_t i,m,n=0,temp,chr1;
uint8_t x0=x,y0=y;
uint8_t size3=size1/8;
while(size3--)
{
chr1=num*size1/8+n;
n++;
for(i=0;i<size1;i++)
{
if(size1==16)
{temp=pgm_read_byte(&Hzk1[chr1][i]);}//调用16*16字体
else if(size1==24)
{temp=pgm_read_byte(&Hzk2[chr1][i]);}//调用24*24字体
else if(size1==32)
{temp=pgm_read_byte(&Hzk3[chr1][i]);}//调用32*32字体
else if(size1==64)
{temp=pgm_read_byte(&Hzk4[chr1][i]);}//调用64*64字体
else return;
for(m=0;m<8;m++)
{
if(temp&0x01)OLED_DrawPoint(x,y);
else OLED_ClearPoint(x,y);
temp>>=1;
y++;
}
x++;
if((x-x0)==size1)
{x=x0;y0=y0+8;}
y=y0;
}
}
}
//配置写入数据的起始位置
void OLED_WR_BP(uint8_t x,uint8_t y)
{
OLED_WR_Byte(0xb0+y,OLED_CMD);//设置行起始地址
OLED_WR_Byte(((x&0xf0)>>4)|0x10,OLED_CMD);
OLED_WR_Byte((x&0x0f),OLED_CMD);
}
//x0,y0：起点坐标
//x1,y1：终点坐标
//BMP[]：要写入的图片数组
void OLED_ShowPicture(uint8_t x0,uint8_t y0,uint8_t x1,uint8_t y1,const uint8_t BMP[])
{
int j=0;
uint8_t t;
uint8_t x,y;
for(y=y0;y<y1;y++)
{
OLED_WR_BP(x0,y);
for(x=x0;x<x1;x++)
{
t=pgm_read_byte(&BMP[j++]);
OLED_WR_Byte(t,OLED_DATA);
}
}
}
//OLED的初始化
void OLED_Init(void)
{
pinMode(scl,OUTPUT);//设置
pinMode(sda,OUTPUT);//设置
pinMode(res,OUTPUT);//设置
OLED_RST_Set();
delay(100);
OLED_RST_Clr();//复位
delay(200);
OLED_RST_Set();
OLED_WR_Byte(0xAE,OLED_CMD);//--turn off oled panel
OLED_WR_Byte(0x00,OLED_CMD);//---set low column address
OLED_WR_Byte(0x10,OLED_CMD);//---set high column address
OLED_WR_Byte(0x40,OLED_CMD);//--set start line address Set Mapping RAM Display Start Line (0x00~0x3F)
OLED_WR_Byte(0x81,OLED_CMD);//--set contrast control register
OLED_WR_Byte(0xCF,OLED_CMD);// Set SEG Output Current Brightness
OLED_WR_Byte(0xA1,OLED_CMD);//--Set SEG/Column Mapping 0xa0左右反置 0xa1正常
OLED_WR_Byte(0xC8,OLED_CMD);//Set COM/Row Scan Direction 0xc0上下反置 0xc8正常
OLED_WR_Byte(0xA6,OLED_CMD);//--set normal display
OLED_WR_Byte(0xA8,OLED_CMD);//--set multiplex ratio(1 to 64)
OLED_WR_Byte(0x3f,OLED_CMD);//--1/64 duty
OLED_WR_Byte(0xD3,OLED_CMD);//-set display offset Shift Mapping RAM Counter (0x00~0x3F)
OLED_WR_Byte(0x00,OLED_CMD);//-not offset
OLED_WR_Byte(0xd5,OLED_CMD);//--set display clock divide ratio/oscillator frequency
OLED_WR_Byte(0x80,OLED_CMD);//--set divide ratio, Set Clock as 100 Frames/Sec
OLED_WR_Byte(0xD9,OLED_CMD);//--set pre-charge period
OLED_WR_Byte(0xF1,OLED_CMD);//Set Pre-Charge as 15 Clocks & Discharge as 1 Clock
OLED_WR_Byte(0xDA,OLED_CMD);//--set com pins hardware configuration
OLED_WR_Byte(0x12,OLED_CMD);
OLED_WR_Byte(0xDB,OLED_CMD);//--set vcomh
OLED_WR_Byte(0x40,OLED_CMD);//Set VCOM Deselect Level
OLED_WR_Byte(0x20,OLED_CMD);//-Set Page Addressing Mode (0x00/0x01/0x02)
OLED_WR_Byte(0x02,OLED_CMD);//
OLED_WR_Byte(0x8D,OLED_CMD);//--set Charge Pump enable/disable
OLED_WR_Byte(0x14,OLED_CMD);//--set(0x10) disable
OLED_WR_Byte(0xA4,OLED_CMD);// Disable Entire Display On (0xa4/0xa5)
OLED_WR_Byte(0xA6,OLED_CMD);// Disable Inverse Display On (0xa6/a7)
OLED_WR_Byte(0xAF,OLED_CMD);
OLED_Clear();
}
void colorWipe(uint32_t c, uint8_t wait) {
for(uint16_t i=0; i<strip.numPixels(); i++) {
strip.setPixelColor(i, c);
strip.show();
delay(wait);
}
}