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.

When using the breadvolt, or any battery power supply on a breadboard project, do not turn the power supply on while the Arduino is connected to USB, as you could generate voltage conflicts. It is an either or. If the USB is connected, the power supply should be OFF. Or if you are going to connect the USB, first turn off the power supply.

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); //***********

}

Technology Tutorials

Portable Arduino Weather Station Project

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