Portable Arduino Weather Station Project

In this video lesson we show how to build a portable Arduino Weather Station. The station is powered by a battery bank, and data is displayed on the SSD1306 OLED display. The station included the BMP180 pressure sensor for barometric pressure, the DHT 11 for temperature and humidity, and a push button to toggle between modes. The schematic of the circuit is shown below.

The code developed in the video is included for your convenience below:

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_BMP085.h>

//**********************************************
#include <DHT.h>
#define DHTPIN 11
#define DHTTYPE DHT11
DHT dht(DHTPIN,DHTTYPE);

int butPin=2;
int butVal=0;
int butValOld=0;
int butCount=0;
int butRem=0;

float tempF;
float tempC;
float hum=50;
int hReadTime=0;
int hReadInt=2000;

float humRaw[128];
float normHum[128];
float tempRaw[128];
float normTemp[128];

int lastUpdate = 0;
int updateInterval = 600;

float rawXdata[128];
int normXdata[128];

float rawYdataP[128];
int normYdataP[128];
float rawYdataH[128];
int normYdataH[128];
float rawYdataT[128];
int normYdataT[128];

float xMin = 0;       //************************************
float xMax = 127;

float yMinP = 28;
float yMaxP = 31;
float yMinH=30;
float yMaxH=90;
float yMinT=60;
float yMaxT=90;

float Pt = 14;
float Pb = 63;

float Pl = 0;
float Pr = 127;

int numPoints = 128;

Adafruit_BMP085 BP;
bool BMPconnected = false;

float BarPress = 30;
float BarPressNow = 30;
float alt = 1127;    //****************************

int screenWidth = 128;
int screenHeight = 64;
int oledReset = -1;
#define SCREEN_ADDRESS 0x3C
Adafruit_SSD1306 oled(screenWidth, screenHeight, &Wire, oledReset);

void setup() {
  // put your setup code here, to run once:
  pinMode(butPin,INPUT_PULLUP); //*********************
  Serial.begin(9600);
  BMPconnected = BP.begin();
  if (BMPconnected == true) {
    Serial.println("BMP180 found and Connected");
  }
  if (BMPconnected == false) {
    Serial.println("BMP180 not found, Check Connections");
  }
  oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  oled.clearDisplay();
  oled.display();
  for (int i = 0; i < numPoints; i= i + 1) {
    rawXdata[i] = i;
  }
  dht.begin();
  delay(2000);
}

void loop() {
  // put your main code here, to run repeatedly:
  BarPressNow = normPress(alt);
  BarPress = .95 * BarPress + .05 * BarPressNow;  
  tempC=BP.readTemperature();         //***********************
  tempF=tempC*9/5 +32;
  if (millis()-hReadTime>hReadInt){
    hum=dht.readHumidity();
    Serial.println(hum);
    hReadTime=millis();
  }

  if (millis() - lastUpdate >= updateInterval) {
    for (int i = 0; i < numPoints - 1; i = i + 1) {
      rawYdataP[i] = rawYdataP[i + 1];
      rawYdataT[i] = rawYdataT[i + 1];
      rawYdataH[i] = rawYdataH[i + 1];
    }
    lastUpdate=millis();
    rawYdataP[numPoints-1]=BarPress;
    rawYdataT[numPoints-1]=tempF;
    rawYdataH[numPoints-1]=hum;
    //normData();
    //oled.clearDisplay();
    //plotGraph();
  }
  butVal=digitalRead(butPin);
  if (butVal==0 && butValOld==1){
    butCount=butCount+1;
    butRem=butCount%4;
  }
  butValOld=butVal;
  if (butRem==0){
  oled.clearDisplay();
  oled.setCursor(0, 0);
  oled.setTextColor(WHITE);
  oled.setTextSize(2);
  oled.print(tempF);
  oled.println(" F");
  oled.print(hum);
  oled.println(" %Hum");
  oled.print(BarPress);
  oled.println(" InHG");
  oled.display();
  }
  if (butRem==1){
  oled.clearDisplay();
  oled.setCursor(0, 0);
  oled.setTextColor(WHITE);
  oled.setTextSize(2);
  oled.print(BarPress);
  oled.setTextSize(1);
  oled.println(" InHG");
  normDataP();             //***********************
  plotPress();           //***********************
  oled.display();
  delay(.1);
  }
  if (butRem==2){
  oled.clearDisplay();
  oled.setCursor(0, 0);
  oled.setTextColor(WHITE);
  oled.setTextSize(2);
  oled.print(tempF);
  oled.setTextSize(1);
  oled.println(" F");
  normDataT();             //***********************
  plotTemp();           //***********************
  oled.display();
  delay(.1);
  }
  if (butRem==3){
  oled.clearDisplay();
  oled.setCursor(0, 0);
  oled.setTextColor(WHITE);
  oled.setTextSize(2);
  oled.print(hum);
  oled.setTextSize(1);
  oled.println(" %HUM");
  normDataH();             //***********************
  plotHum();           //***********************
  oled.display();
  delay(.1);
  }
}

float normPress(float elev) {
  float BPRaw;
  float BPNorm;
  float T0 = 288.15;
  float L = .0065;
  float R = 8.3144598;
  float M = .0289644;
  float g = 9.8;
  float c = M * g / (R * L);
  BPRaw = BP.readPressure() * .0002953;
  BPNorm = BPRaw / pow(1 - L * elev / T0, c);
  return BPNorm;
}
void normDataP() {
  for (int i = 0; i < numPoints; i = i + 1) {
    normYdataP[i] = (Pb - Pt) / (yMinP - yMaxP) * (rawYdataP[i] - yMaxP) + Pt;
    normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;
  }
}
  void normDataT() {
  for (int i = 0; i < numPoints; i = i + 1) {
    normYdataT[i] = (Pb - Pt) / (yMinT - yMaxT) * (rawYdataT[i] - yMaxT) + Pt;
    normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;
  }
  }
  void normDataH() {
  for (int i = 0; i < numPoints; i = i + 1) {
    normYdataH[i] = (Pb - Pt) / (yMinH - yMaxH) * (rawYdataH[i] - yMaxH) + Pt;
    normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;
  }
}
void plotPress() {                    //plot Pressure
  oled.drawLine(Pl, Pt, Pl, Pb, WHITE);
  oled.drawLine(Pl, Pb, Pr, Pb, WHITE);
  int MID = (Pb - Pt) / (yMinP - yMaxP) * (29.92 - yMaxP) + Pt;    //********** 
  oled.drawLine(Pl, MID, Pr, MID, WHITE);
  for (int i = 0; i < numPoints - 1; i = i + 1) {
    oled.drawLine(normXdata[i], normYdataP[i], normXdata[i + 1], normYdataP[i + 1], WHITE); //***********
  }
}
void plotTemp() {                    //plot Pressure
  oled.drawLine(Pl, Pt, Pl, Pb, WHITE);
  oled.drawLine(Pl, Pb, Pr, Pb, WHITE);
  //int MID = (Pb - Pt) / (yMinP - yMaxP) * (29.92 - yMaxP) + Pt;    //********** 
  //oled.drawLine(Pl, MID, Pr, MID, WHITE);
  for (int i = 0; i < numPoints - 1; i = i + 1) {
    oled.drawLine(normXdata[i], normYdataT[i], normXdata[i + 1], normYdataT[i + 1], WHITE); //***********
  }
}
void plotHum() {                    //plot Pressure
  oled.drawLine(Pl, Pt, Pl, Pb, WHITE);
  oled.drawLine(Pl, Pb, Pr, Pb, WHITE);
  //int MID = (Pb - Pt) / (yMinP - yMaxP) * (29.92 - yMaxP) + Pt;    //********** 
  //oled.drawLine(Pl, MID, Pr, MID, WHITE);
  for (int i = 0; i < numPoints - 1; i = i + 1) {
    oled.drawLine(normXdata[i], normYdataH[i], normXdata[i + 1], normYdataH[i + 1], WHITE); //***********
  }
}

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#include <SPI.h>

#include <Wire.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

#include <Adafruit_BMP085.h>

//**********************************************

#include <DHT.h>

#define DHTPIN 11

#define DHTTYPE DHT11

DHT dht(DHTPIN,DHTTYPE);

int butPin=2;

int butVal=0;

int butValOld=0;

int butCount=0;

int butRem=0;

float tempF;

float tempC;

float hum=50;

int hReadTime=0;

int hReadInt=2000;

float humRaw[128];

float normHum[128];

float tempRaw[128];

float normTemp[128];

int lastUpdate = 0;

int updateInterval = 600;

float rawXdata[128];

int normXdata[128];

float rawYdataP[128];

int normYdataP[128];

float rawYdataH[128];

int normYdataH[128];

float rawYdataT[128];

int normYdataT[128];

float xMin = 0; //************************************

float xMax = 127;

float yMinP = 28;

float yMaxP = 31;

float yMinH=30;

float yMaxH=90;

float yMinT=60;

float yMaxT=90;

float Pt = 14;

float Pb = 63;

float Pl = 0;

float Pr = 127;

int numPoints = 128;

Adafruit_BMP085 BP;

bool BMPconnected = false;

float BarPress = 30;

float BarPressNow = 30;

float alt = 1127; //****************************

int screenWidth = 128;

int screenHeight = 64;

int oledReset = -1;

#define SCREEN_ADDRESS 0x3C

Adafruit_SSD1306 oled(screenWidth, screenHeight, &Wire, oledReset);

void setup() {

// put your setup code here, to run once:

pinMode(butPin,INPUT_PULLUP); //*********************

Serial.begin(9600);

BMPconnected = BP.begin();

if (BMPconnected == true) {

Serial.println("BMP180 found and Connected");

}

if (BMPconnected == false) {

Serial.println("BMP180 not found, Check Connections");

}

oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);

oled.clearDisplay();

oled.display();

for (int i = 0; i < numPoints; i= i + 1) {

rawXdata[i] = i;

}

dht.begin();

delay(2000);

}

void loop() {

// put your main code here, to run repeatedly:

BarPressNow = normPress(alt);

BarPress = .95 * BarPress + .05 * BarPressNow;

tempC=BP.readTemperature(); //***********************

tempF=tempC*9/5 +32;

if (millis()-hReadTime>hReadInt){

hum=dht.readHumidity();

Serial.println(hum);

hReadTime=millis();

}

if (millis() - lastUpdate >= updateInterval) {

for (int i = 0; i < numPoints - 1; i = i + 1) {

rawYdataP[i] = rawYdataP[i + 1];

rawYdataT[i] = rawYdataT[i + 1];

rawYdataH[i] = rawYdataH[i + 1];

}

lastUpdate=millis();

rawYdataP[numPoints-1]=BarPress;

rawYdataT[numPoints-1]=tempF;

rawYdataH[numPoints-1]=hum;

//normData();

//oled.clearDisplay();

//plotGraph();

}

butVal=digitalRead(butPin);

if (butVal==0 && butValOld==1){

butCount=butCount+1;

butRem=butCount%4;

}

butValOld=butVal;

if (butRem==0){

oled.clearDisplay();

oled.setCursor(0, 0);

oled.setTextColor(WHITE);

oled.setTextSize(2);

oled.print(tempF);

oled.println(" F");

oled.print(hum);

oled.println(" %Hum");

oled.print(BarPress);

oled.println(" InHG");

oled.display();

}

if (butRem==1){

oled.clearDisplay();

oled.setCursor(0, 0);

oled.setTextColor(WHITE);

oled.setTextSize(2);

oled.print(BarPress);

oled.setTextSize(1);

oled.println(" InHG");

normDataP(); //***********************

plotPress(); //***********************

oled.display();

delay(.1);

}

if (butRem==2){

oled.clearDisplay();

oled.setCursor(0, 0);

oled.setTextColor(WHITE);

oled.setTextSize(2);

oled.print(tempF);

oled.setTextSize(1);

oled.println(" F");

normDataT(); //***********************

plotTemp(); //***********************

oled.display();

delay(.1);

}

if (butRem==3){

oled.clearDisplay();

oled.setCursor(0, 0);

oled.setTextColor(WHITE);

oled.setTextSize(2);

oled.print(hum);

oled.setTextSize(1);

oled.println(" %HUM");

normDataH(); //***********************

plotHum(); //***********************

oled.display();

delay(.1);

}

float normPress(float elev) {

float BPRaw;

float BPNorm;

float T0 = 288.15;

float L = .0065;

float R = 8.3144598;

float M = .0289644;

float g = 9.8;

float c = M * g / (R * L);

BPRaw = BP.readPressure() * .0002953;

BPNorm = BPRaw / pow(1 - L * elev / T0, c);

return BPNorm;

}

void normDataP() {

for (int i = 0; i < numPoints; i = i + 1) {

normYdataP[i] = (Pb - Pt) / (yMinP - yMaxP) * (rawYdataP[i] - yMaxP) + Pt;

normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;

}

void normDataT() {

for (int i = 0; i < numPoints; i = i + 1) {

normYdataT[i] = (Pb - Pt) / (yMinT - yMaxT) * (rawYdataT[i] - yMaxT) + Pt;

normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;

}

void normDataH() {

for (int i = 0; i < numPoints; i = i + 1) {

normYdataH[i] = (Pb - Pt) / (yMinH - yMaxH) * (rawYdataH[i] - yMaxH) + Pt;

normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;

}

void plotPress() { //plot Pressure

oled.drawLine(Pl, Pt, Pl, Pb, WHITE);

oled.drawLine(Pl, Pb, Pr, Pb, WHITE);

int MID = (Pb - Pt) / (yMinP - yMaxP) * (29.92 - yMaxP) + Pt; //**********

oled.drawLine(Pl, MID, Pr, MID, WHITE);

for (int i = 0; i < numPoints - 1; i = i + 1) {

oled.drawLine(normXdata[i], normYdataP[i], normXdata[i + 1], normYdataP[i + 1], WHITE); //***********

}

void plotTemp() { //plot Pressure

oled.drawLine(Pl, Pt, Pl, Pb, WHITE);

oled.drawLine(Pl, Pb, Pr, Pb, WHITE);

//int MID = (Pb - Pt) / (yMinP - yMaxP) * (29.92 - yMaxP) + Pt; //**********

//oled.drawLine(Pl, MID, Pr, MID, WHITE);

for (int i = 0; i < numPoints - 1; i = i + 1) {

oled.drawLine(normXdata[i], normYdataT[i], normXdata[i + 1], normYdataT[i + 1], WHITE); //***********

}

void plotHum() { //plot Pressure

oled.drawLine(Pl, Pt, Pl, Pb, WHITE);

oled.drawLine(Pl, Pb, Pr, Pb, WHITE);

//int MID = (Pb - Pt) / (yMinP - yMaxP) * (29.92 - yMaxP) + Pt; //**********

//oled.drawLine(Pl, MID, Pr, MID, WHITE);

for (int i = 0; i < numPoints - 1; i = i + 1) {

oled.drawLine(normXdata[i], normYdataH[i], normXdata[i + 1], normYdataH[i + 1], WHITE); //***********

}

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Portable Arduino Weather Station Project

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