【项目简介】

         硬禾学堂联合digikey进行的funpack第12期活动，硬件选取了功能强大的wio termial 作为本次活动的硬件平台，wio terminal自身有很多传感器并且有一个320x240TFTLCD,可以实现众多功能，借助arduino丰富的资源实现快速开发， 本期有三个任务，我选取任务一，自己准备至少三个外置传感器，并进行读取显示在wio terminal 的lcd屏上。

【开发环境】

软件：

OS：ubuntu20.04

IDE: Arduino IDE 1.8.16

硬件：

wio terminal   1

ccs811 sensor 1

tcs32745 sensor 1

dht22 sensor 1

【步骤】

1.DHT22也称AM2302，是一款含有已校准数字信号输出的温湿度复合传感器，见图1，湿度量程范围0~99.9%RH，精度±2%RH，而温度量程范围是-40℃~80℃，精度±0.5℃。DHT22是单总线通信的，驱动它只需三根线：电源线、信号线和地线，因此其电路也很简单

导入 DHT22库，附上例程代码，在使用DHT22时要注意，读取间隔最好大于2秒

#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <DHT_U.h>

#define DHTPIN 2     // Digital pin connected to the DHT sensor 
// Feather HUZZAH ESP8266 note: use pins 3, 4, 5, 12, 13 or 14 --
// Pin 15 can work but DHT must be disconnected during program upload.

// Uncomment the type of sensor in use:
//#define DHTTYPE    DHT11     // DHT 11
#define DHTTYPE    DHT22     // DHT 22 (AM2302)
//#define DHTTYPE    DHT21     // DHT 21 (AM2301)

// See guide for details on sensor wiring and usage:
//   https://learn.adafruit.com/dht/overview

DHT_Unified dht(DHTPIN, DHTTYPE);

uint32_t delayMS;

void setup() {
  Serial.begin(9600);
  // Initialize device.
  dht.begin();
  Serial.println(F("DHTxx Unified Sensor Example"));
  // Print temperature sensor details.
  sensor_t sensor;
  dht.temperature().getSensor(&sensor);
  Serial.println(F("------------------------------------"));
  Serial.println(F("Temperature Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("°C"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("°C"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("°C"));
  Serial.println(F("------------------------------------"));
  // Print humidity sensor details.
  dht.humidity().getSensor(&sensor);
  Serial.println(F("Humidity Sensor"));
  Serial.print  (F("Sensor Type: ")); Serial.println(sensor.name);
  Serial.print  (F("Driver Ver:  ")); Serial.println(sensor.version);
  Serial.print  (F("Unique ID:   ")); Serial.println(sensor.sensor_id);
  Serial.print  (F("Max Value:   ")); Serial.print(sensor.max_value); Serial.println(F("%"));
  Serial.print  (F("Min Value:   ")); Serial.print(sensor.min_value); Serial.println(F("%"));
  Serial.print  (F("Resolution:  ")); Serial.print(sensor.resolution); Serial.println(F("%"));
  Serial.println(F("------------------------------------"));
  // Set delay between sensor readings based on sensor details.
  delayMS = sensor.min_delay / 1000;
}

void loop() {
  // Delay between measurements.
  delay(delayMS);
  // Get temperature event and print its value.
  sensors_event_t event;
  dht.temperature().getEvent(&event);
  if (isnan(event.temperature)) {
    Serial.println(F("Error reading temperature!"));
  }
  else {
    Serial.print(F("Temperature: "));
    Serial.print(event.temperature);
    Serial.println(F("°C"));
  }
  // Get humidity event and print its value.
  dht.humidity().getEvent(&event);
  if (isnan(event.relative_humidity)) {
    Serial.println(F("Error reading humidity!"));
  }
  else {
    Serial.print(F("Humidity: "));
    Serial.print(event.relative_humidity);
    Serial.println(F("%"));
  }
}

编译下载到开发板，并打开串口监视器，对着传感器吹了一口气，瞬间数值发生变化。

2. tcs34725 RGB识别传感器，数据手册比较详细，列出部分内容如下

特性：

所述TCS34725 I2C Arduino的彩色传感器具有高灵敏度，动态范围宽，并包括一个IR阻挡滤波器使其变化的照明条件下使用的理想颜色感测解决方案。TCS34725 颜色传感器还包括四个超亮 LED，允许传感器在没有外部光源的情况下工作。该模块通过您的 Arduino 的 I2C 总线工作，并包括 PH2.0-4P 和 XH2.54（面包板）接口，以满足一系列用户场景。

规格：
工作电压：3.3~5V
工作电流：65 uA
检测范围：3-10 mm
时钟频率：0-400 KHZ
接口：IIC接口
IIC地址：0x29
温度范围： - 30 ℃ ~ + 70 ℃
英尺英寸：18.5 * 23 毫米/ 0.73 * 0.9 英寸
重量：12 克

代码：导入Adafruit_TCS34725库，代码如下

#include <Wire.h>
#include "DFRobot_TCS34725.h"

// Pick analog outputs, for the UNO these three work well
// use ~560  ohm resistor between Red & Blue, ~1K for green (its brighter)
#define redpin 3
#define greenpin 5
#define bluepin 6
// for a common anode LED, connect the common pin to +5V
// for common cathode, connect the common to ground

// set to false if using a common cathode LED
#define commonAnode true

// our RGB -> eye-recognized gamma color
byte gammatable[256];

DFRobot_TCS34725 tcs = DFRobot_TCS34725(TCS34725_INTEGRATIONTIME_50MS, TCS34725_GAIN_4X);
void setup() {
  Serial.begin(115200);
  Serial.println("Color View Test!");

  if (tcs.begin()) {
    Serial.println("Found sensor");
  } else {
    Serial.println("No TCS34725 found ... check your connections");
    while (1); // halt!
  }
  // use these three pins to drive an LED
  pinMode(redpin, OUTPUT);
  pinMode(greenpin, OUTPUT);
  pinMode(bluepin, OUTPUT);
  
  // thanks PhilB for this gamma table!
  // it helps convert RGB colors to what humans see
  for (int i=0; i<256; i++) {
    float x = i;
    x /= 255;
    x = pow(x, 2.5);
    x *= 255;
      
    if (commonAnode) {
      gammatable[i] = 255 - x;
    } else {
      gammatable[i] = x;      
    }
    //Serial.println(gammatable[i]);
  }
}

void loop() {
  uint16_t clear, red, green, blue;
  tcs.getRGBC(&red, &green, &blue, &clear);
  tcs.lock();  // turn off LED
  Serial.print("C:\t"); Serial.print(clear);
  Serial.print("\tR:\t"); Serial.print(red);
  Serial.print("\tG:\t"); Serial.print(green);
  Serial.print("\tB:\t"); Serial.print(blue);
  Serial.println("\t");
  
  // Figure out some basic hex code for visualization
  uint32_t sum = clear;
  float r, g, b;
  r = red; r /= sum;
  g = green; g /= sum;
  b = blue; b /= sum;
  r *= 256; g *= 256; b *= 256;
  Serial.print("\t");
  Serial.print((int)r, HEX); Serial.print((int)g, HEX); Serial.print((int)b, HEX);
  Serial.println();

  //Serial.print((int)r ); Serial.print(" "); Serial.print((int)g);Serial.print(" ");  Serial.println((int)b );
  //Set the color lamp
  analogWrite(redpin, gammatable[(int)r]);
  analogWrite(greenpin, gammatable[(int)g]);
  analogWrite(bluepin, gammatable[(int)b]);
}

编译下载到开发板，并打开串口监视器，获取RGB颜色数值

3.ccs811 co2/tvoc传感器，一般用于空气净化器，空调等检测室内空气质量并据此进行新风系统的换气控制。

特性

导入DFRobot_CCS811库，代码如下

#include "DFRobot_CCS811.h"

/*
 * IIC address default 0x5A, the address becomes 0x5B if the ADDR_SEL is soldered.
 */
//DFRobot_CCS811 CCS811(&Wire, /*IIC_ADDRESS=*/0x5A);
DFRobot_CCS811 CCS811;

void setup(void)
{
    Serial.begin(115200);
    /*Wait for the chip to be initialized completely, and then exit*/
    while(CCS811.begin() != 0){
        Serial.println("failed to init chip, please check if the chip connection is fine");
        delay(1000);
    }
}
void loop() {
    if(CCS811.checkDataReady() == true){
        Serial.print("CO2: ");
        Serial.print(CCS811.getCO2PPM());
        Serial.print("ppm, TVOC: ");
        Serial.print(CCS811.getTVOCPPB());
        Serial.println("ppb");
        
    } else {
        Serial.println("Data is not ready!");
    }
    /*!
     * @brief Set baseline
     * @param get from getBaseline.ino
     */
    CCS811.writeBaseLine(0x447B);
    //delay cannot be less than measurement cycle
    delay(1000);
}

编译下载到开发板，并打开串口监视器，co2/tvoc数值如下图所示。

4.为了互动，初始化wio terminial的按键，LCD，直接上代码

先加入按建中断，处理按键事件

 button_init();

   attachInterrupt(digitalPinToInterrupt(WIO_5S_RIGHT),OnChange,CHANGE);
    attachInterrupt(digitalPinToInterrupt(WIO_5S_DOWN),OnChange,CHANGE);
     attachInterrupt(digitalPinToInterrupt(WIO_5S_LEFT),OnChange,CHANGE);
      attachInterrupt(digitalPinToInterrupt(WIO_5S_UP),OnChange,CHANGE);

void OnChange(){

   if(digitalRead(WIO_5S_UP)==LOW||digitalRead(WIO_5S_RIGHT)==LOW)
      {
        
        menulist++;
        
        if(menulist>3)
        menulist=1;
        }
      if(digitalRead(WIO_5S_DOWN)==LOW||digitalRead(WIO_5S_LEFT)==LOW)
      {
        menulist--;
        if(menulist<1)
        menulist=3;
        
      }


}

导入seeed lcd库，直接调用即可。

5. 实现简单的gui操作，通过第4步的按钮操作实现简单的互动。

 
      switch (menulist){
        
        case 1 : tcs34725_function();
        break;
        case 2 : DHT_funcion();
        break;
        case 3 : CCS811_function();
        break;
        default:
        break;
       
        
        }

  

6. 加入图表，导入seeed_line_chart库，并在ccs811及DHT22传感器中增加图表

 void DHT_funcion(){
// Delay between measurements.
  if(menulist!=menuchgflag){
  tft.fillScreen(TFT_GREY);
  
  menuchgflag=menulist;}
  delay(delayMS);
   
   if (accelerator_readings[0].size() == max_size) {
      for (uint8_t i = 0; i<3; i++){
        accelerator_readings[i].pop(); //this is used to remove the first read variable
      }
    }

  
  // Get temperature event and print its value.
  sensors_event_t event;
  dht.temperature().getEvent(&event);
  if (isnan(event.temperature)) {
    Serial.println(F("Error reading temperature!"));
  }
  else {
    Serial.print(F("Temperature: "));
    Serial.print(event.temperature);
    Serial.println(F("°C"));

    spr.createSprite(120, 30);
    spr.fillSprite(TFT_RED);
    spr.setFreeFont(&FreeSansBoldOblique12pt7b);
    spr.setTextColor(TFT_BLACK);
    spr.drawString("Tmp:",1,0,1);
    spr.drawNumber(float(event.temperature), 70 , 0, 1);
    spr.drawString("°C",100,0,1);
    spr.pushSprite(30 , 5);
    spr.deleteSprite();
 accelerator_readings[0].push(event.temperature);
    
  }
  // Get humidity event and print its value.
  dht.humidity().getEvent(&event);
  if (isnan(event.relative_humidity)) {
    Serial.println(F("Error reading humidity!"));
  }
  else {
    Serial.print(F("Humidity: "));
    Serial.print(event.relative_humidity);
    Serial.println(F("%"));



     spr.createSprite(120, 30);
    spr.fillSprite(TFT_GREEN);
    spr.setFreeFont(&FreeSansBoldOblique12pt7b);
    spr.setTextColor(TFT_BLACK);
    spr.drawString("Hum:",1,0,1);
    spr.drawNumber(float(event.relative_humidity), 70 , 0, 1);
    spr.drawString("%",100,0,1);
    spr.pushSprite(150 , 5);
    spr.deleteSprite();
    accelerator_readings[1].push(event.relative_humidity);
  }
spr.createSprite(320, 200);
spr.fillSprite(TFT_WHITE);
 //Settings for the line graph title
    auto header =  text(0, 0)
                .value("Temperature/Humidity Readings")
                .align(center)
                .valign(vcenter)
                .width(tft.width())
                .thickness(2);
 
    header.height(header.font_height() * 2);
    header.draw(); //Header height is the twice the height of the font
        
 //Settings for the line graph
    auto content = line_chart(20, header.height()); //(x,y) where the line graph begins
         content
                .height(tft.height() - header.height() * 1.5) //actual height of the line chart
                .width(tft.width() - content.x() * 2) //actual width of the line chart
                .based_on(-2.0) //Starting point of y-axis, must be a float
                .show_circle(false) //drawing a cirle at each point, default is on.
                .value({accelerator_readings[0],accelerator_readings[1]}) //passing through the data to line graph
                .color(TFT_RED, TFT_GREEN)
                .draw();
 
    spr.pushSprite(5, 30);
     spr.deleteSprite();
    delay(50);


   }

 void  CCS811_function(){
 // tft.fillScreen(TFT_GREY);
 if(menulist!=menuchgflag){
  tft.fillScreen(TFT_GREY);
  
  menuchgflag=menulist;}

    if(CCS811.checkDataReady() == true){
        Serial.print("CO2: ");
        Serial.print(CCS811.getCO2PPM());
        Serial.print("ppm, TVOC: ");
        Serial.print(CCS811.getTVOCPPB());
        Serial.println("ppb");

if (accelerator_readings[0].size() == max_size) {
      for (uint8_t i = 0; i<3; i++){
        accelerator_readings[i].pop(); //this is used to remove the first read variable
      }
    }
accelerator_readings[0].push(CCS811.getCO2PPM());
accelerator_readings[1].push(CCS811.getTVOCPPB());
 spr.createSprite(120, 30);
    spr.fillSprite(TFT_RED);
    spr.setFreeFont(&FreeSansBoldOblique12pt7b);
    spr.setTextColor(TFT_BLACK);
    spr.drawString("CO2:",1,0,1);
    spr.drawNumber(float(CCS811.getCO2PPM()), 70 , 0, 1);
    spr.pushSprite(30 , 5);
    spr.deleteSprite();

 spr.createSprite(120, 30);
    spr.fillSprite(TFT_GREEN);
    spr.setFreeFont(&FreeSansBoldOblique12pt7b);
    spr.setTextColor(TFT_BLACK);
    spr.drawString("TVOC:",1,0,1);
    spr.drawNumber(float(CCS811.getTVOCPPB()), 70 , 0, 1);
    spr.pushSprite(150 , 5);
    spr.deleteSprite();


        spr.createSprite(320, 200);
spr.fillSprite(TFT_WHITE);
 //Settings for the line graph title
    auto header =  text(0, 0)
                .value("CO2/TVOC Readings")
                .align(center)
                .valign(vcenter)
                .width(tft.width())
                .thickness(2);
 
    header.height(header.font_height() * 2);
    header.draw(); //Header height is the twice the height of the font
        
 //Settings for the line graph
    auto content = line_chart(20, header.height()); //(x,y) where the line graph begins
         content
                .height(tft.height() - header.height() * 1.5) //actual height of the line chart
                .width(tft.width() - content.x() * 2) //actual width of the line chart
                .based_on(-2.0) //Starting point of y-axis, must be a float
                .show_circle(false) //drawing a cirle at each point, default is on.
                .value({accelerator_readings[0],accelerator_readings[1]}) //passing through the data to line graph
                .color(TFT_RED, TFT_GREEN)
                .draw();
 
    spr.pushSprite(5, 30);
     spr.deleteSprite();
    delay(50);
        
    } else {
        Serial.println("Data is not ready!");
    }
    /*!
     * @brief Set baseline
     * @param get from getBaseline.ino
     */
    CCS811.writeBaseLine(0x447B);
    //delay cannot be less than measurement cycle
    delay(1000);




   }
   

【综述】

本期活动丰富多彩，三个活动各有侧重，难易不尽相同，任务一传感器的是万物互联的基础，本次选用了3个有代表性的传感器，dht22温湿度，ccs811空气质量传感器，tcs34725色彩传感器，借助arduino丰富的资源库，基本上实现了各个传感器的相应的功能。