Need help in correct ways to use delay in merge DHT 22 and Sharp's GP2Y1010AU0F

Projects Programming
1

I need help verifying my coding. I am using Arduino Uno with sensor DHT 22 and Sharp's GP2Y1010AU0F.

  1. My result is too slow. from my understanding is because of delay() and delayMicroseconds().
  2. the result is overlapping. if I want to stream the data, it will place the result in the same table.
/* DHT-22 sensor with 12c 16x2 LCD with Arduino uno
   Temperature and humidity sensor displayed in LCD
   based on: http://www.ardumotive.com/how-to-use-dht-22-sensor-en.html and
   https://www.ardumotive.com/i2clcden.html for the i2c LCD library by Michalis Vasilakis
   Recompile by adhitadhitadhit
   Notes: use LCD i2c Library from link above, i'm not sure why but new Liquidcristal library from Francisco Malpartida  isn't working for me
   other thing, check your */

/////////////////////////////////////////////////////////////////////////////
// Sharp GP2Y1014AU0F Dust Sensor Demo
//
// Board Connection:
//   GP2Y1014    Arduino
//   V-LED       Between R1 and C1
//   LED-GND     C1 and GND
//   LED         Pin 4
//   S-GND       GND
//   Vo          A5
//   Vcc         5V
//
// Serial monitor setting:
//   9600 baud
/////////////////////////////////////////////////////////////////////////////


//Libraries
// Choose program options.
//#define PRINT_RAW_DATA
#define USE_AVG
#include <dht.h>  // sensor library using lib from https://www.ardumotive.com/how-to-use-dht-22-sensor-en.html
//#include <LiquidCrystal_I2C.h> // LCD library using from  https://www.ardumotive.com/i2clcden.html for the i2c LCD library
//#include <Wire.h>
dht DHT;

//Constants
#define DHT22_PIN 3  // DHT 22  (AM2302) - pin used for DHT22
// Arduino pin numbers.
const int sharpLEDPin = 4;  // Arduino digital pin 7 connect to sensor LED.
const int sharpVoPin = A5;  // Arduino analog pin 5 connect to sensor Vo.

// For averaging last N raw voltage readings.
#ifdef USE_AVG
#define N 100
static unsigned long VoRawTotal = 0;
static int VoRawCount = 0;
#endif  // USE_AVG

// Set the typical output voltage in Volts when there is zero dust.
static float Voc = 0.6;

// Use the typical sensitivity in units of V per 100ug/m3.
const float K = 0.5;

//Variables
float hum;   //Stores humidity value
float temp;  //Stores temperature value

// Helper functions to print a data value to the serial monitor.
void printValue(String text, unsigned int value, bool isLast = false) {
  Serial.print(text);
  Serial.print("=");
  Serial.print(value);
  if (!isLast) {
    Serial.print(", ");
  }
}
void printFValue(String text, float value, String units, bool isLast = false) {
  Serial.print(text);
  Serial.print("=");
  Serial.print(value);
  Serial.print(units);
  if (!isLast) {
    Serial.print(", ");
  }
}

void setup() {

  pinMode(sharpLEDPin, OUTPUT);
  Serial.begin(9600);

  // delay(2000);
  // Serial.println("");
  //Serial.println("=================");
}

void loop() {
  int chk = DHT.read22(DHT22_PIN);
  //Read data and store it to variables hum and temp
  hum = DHT.humidity;
  temp = DHT.temperature;

  digitalWrite(sharpLEDPin, LOW);

  // Wait 0.28ms before taking a reading of the output voltage as per spec.
  delayMicroseconds(280);

  // Record the output voltage. This operation takes around 100 microseconds.
  int VoRaw = analogRead(sharpVoPin);

  // Turn the dust sensor LED off by setting digital pin HIGH.
  digitalWrite(sharpLEDPin, HIGH);

  // Wait for remainder of the 10ms cycle = 10000 - 280 - 100 microseconds.
  delayMicroseconds(9620);

// Print raw voltage value (number from 0 to 1023).
#ifdef PRINT_RAW_DATA
  printValue("VoRaw", VoRaw, true);
  Serial.println("");
#endif  // PRINT_RAW_DATA

  // Use averaging if needed.
  float Vo = VoRaw;
#ifdef USE_AVG
  VoRawTotal += VoRaw;
  VoRawCount++;
  if (VoRawCount >= N) {
    Vo = 1.0 * VoRawTotal / N;
    VoRawCount = 0;
    VoRawTotal = 0;
  } else {
    return;
  }
#endif  // USE_AVG

  // Compute the output voltage in Volts.
  Vo = Vo / 1024.0 * 5.0;

  //Display
  printFValue("Vo", Vo * 1000.0, "mV");

  // Convert to Dust Density in units of ug/m3.
  float dV = Vo - Voc;
  if (dV < 0) {
    dV = 0;
    Voc = Vo;
  }
  float dustDensity = dV / K * 100.0;
  printFValue("DustDensity", dustDensity, "ug/m3", true);
  //Serial.println(" ");

  //Print temp and humidity values to serial monitor
  Serial.print(" ");
  Serial.print("Humidity: ");
  Serial.print(hum);
  Serial.print(" %, Temp: ");
  Serial.print(temp);
  Serial.println(" Celsius");


  //delay(2000);  //Delay 2 sec.
}

Thank You.

2

Serial print can be slow. Increase the baud rate. Remove delays and replace with millis/micros timers

3

So I need to change like this?

Serial.begin(115200);
4

Also in your serial monitor as they have to match. But the delays are probably more important.

5

Thank you for the link. let me study first .

6

Take a look at

Using millis() for timing. A beginners guide, Several things at the same time and the BlinkWithoutDelay example in the IDE

7

You can do a serialprint of millis each time through loop and thus you know how long a loop takes. Then make changes and see the effect.

9

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