Tag Archives: BMP180

Portable Arduino Weather Station Project

March 20, 2025 admin

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

}

Arduino

Portable Arduino Barometric Weather Station

March 13, 2025 admin

In this video lesson we take you through the project of building an Arduino Barometric Pressure Weather Station. It builds on the last two lessons in this series. We measure and display instantaneous Barometric Pressure, normalized to Sea Level. Then in the lower portion on the OLED SSD1306 display, we show a graph of the barometric pressure over the last 24 hours.

Schematic for the Portable Arduino Barometric Pressure Sensor

When using the breadvolt, or any battery power supply on a breadboard project, do not turn the power supply on while the Raspberry Pi Pico 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.

Below we include the code we develop in the above video. Make sure to set the ‘alt’ variable to your elevation at your location, in meters.

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

int lastUpdate = 0;
int updateInterval = 600000;

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

float rawYdata[128];
int normYdata[128];

float xMin = 0;
float xMax = 127;

float yMin = 28;
float yMax = 31;

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:
  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;
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  BarPressNow = normPress(alt);
  BarPress = .95 * BarPress + .05 * BarPressNow;
  if (millis() - lastUpdate >= updateInterval) {
    for (int i = 0; i < numPoints - 1; i = i + 1) {
      rawYdata[i] = rawYdata[i + 1];

    }
    lastUpdate=millis();
    rawYdata[numPoints-1]=BarPress;
    normData();
    oled.clearDisplay();
    plotGraph();
  }
  oled.clearDisplay();
  oled.setCursor(0, 0);
  oled.setTextColor(WHITE);
  oled.setTextSize(2);
  oled.print(BarPress);
  oled.setTextSize(1);
  oled.println(" In HG");
  normData();
  plotGraph();
  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 normData() {
  for (int i = 0; i < numPoints; i = i + 1) {
    normYdata[i] = (Pb - Pt) / (yMin - yMax) * (rawYdata[i] - yMax) + Pt;
    normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;
  }
}
void plotGraph() {
  oled.drawLine(Pl, Pt, Pl, Pb, WHITE);
  oled.drawLine(Pl, Pb, Pr, Pb, WHITE);
  int MID = (Pb - Pt) / (yMin - yMax) * (29.92 - yMax) + Pt;
  oled.drawLine(Pl, MID, Pr, MID, WHITE);
  for (int i = 0; i < numPoints - 1; i = i + 1) {
    oled.drawLine(normXdata[i], normYdata[i], normXdata[i + 1], normYdata[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>

int lastUpdate = 0;

int updateInterval = 600000;

float rawXdata[128];

int normXdata[128];

float rawYdata[128];

int normYdata[128];

float xMin = 0;

float xMax = 127;

float yMin = 28;

float yMax = 31;

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:

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;

}

void loop() {

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

BarPressNow = normPress(alt);

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

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

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

rawYdata[i] = rawYdata[i + 1];

}

lastUpdate=millis();

rawYdata[numPoints-1]=BarPress;

normData();

oled.clearDisplay();

plotGraph();

}

oled.clearDisplay();

oled.setCursor(0, 0);

oled.setTextColor(WHITE);

oled.setTextSize(2);

oled.print(BarPress);

oled.setTextSize(1);

oled.println(" In HG");

normData();

plotGraph();

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 normData() {

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

normYdata[i] = (Pb - Pt) / (yMin - yMax) * (rawYdata[i] - yMax) + Pt;

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

}

void plotGraph() {

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

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

int MID = (Pb - Pt) / (yMin - yMax) * (29.92 - yMax) + Pt;

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

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

oled.drawLine(normXdata[i], normYdata[i], normXdata[i + 1], normYdata[i + 1], WHITE);

}

Arduino

Arduino Weather Barometer

February 27, 2025 admin

In this video lesson we show how to build an Arduino based Weather Barometer. We will use the BMP180 pressure sensor on the GY-87 module. This lesson will likely also work fine if you are just using the BMP180 directly. We show how to measure barometric pressure, convert it to Inches of Mercury, stabilize it with a low pass filter, and then normalize it to standard sea level pressure. With this, our values should very closely match what is being seen on weather maps. This is the schematic of the circuit we will be working on.

Schematic for the Portable Arduino Barometer

For your convenience, here is the code we developed in the video.

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

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:
  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();
}

void loop() {
  // put your main code here, to run repeatedly:
  BarPressNow = normPress(alt);
  BarPress = .95*BarPress + .05*BarPressNow;
  oled.clearDisplay();
  oled.setCursor(0,12);
  oled.setTextColor(WHITE);
  oled.setTextSize(3);
  oled.println(BarPress);
  oled.println("In HG");
  oled.display();
}

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;
}

#include <SPI.h>

#include <Wire.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

#include <Adafruit_BMP085.h>

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:

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();

}

void loop() {

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

BarPressNow = normPress(alt);

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

oled.clearDisplay();

oled.setCursor(0,12);

oled.setTextColor(WHITE);

oled.setTextSize(3);

oled.println(BarPress);

oled.println("In HG");

oled.display();

}

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;

}

Arduino

Portable Altimeter Project with Arduino

February 20, 2025 admin

In this video lesson we create a portable altimeter that measures altitude above a base reference location. The device uses an arduino uno R4 Wifi, a BMP180 pressure sensor which is on the GY-87 module. For your convenience, we present the circuit diagram used below:

Schematic for the Portable Arduino Altimeter

This is the code for this project, for your convenience.

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

Adafruit_BMP085 BP;
bool BMPconnected;
bool haveBase = false;

int butPin = 2;
int butVal = 1;
int butValOld = 1;

float basePressure;
float Height = 0;
float HeightNow = 0;
int feet;
int inches;


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:
  Serial.begin(9600);
  pinMode(butPin, INPUT_PULLUP);
  delay(250);
  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.setCursor(0, 12);
  oled.setTextColor(WHITE);
  oled.setTextSize(1);
  oled.println("Place the Deluxe ");
  oled.println("HeightOmatic at");
  oled.println("Base Location, and");
  oled.println("Press Go!");
  oled.display();
}

void loop() {
  // put your main code here, to run repeatedly:
  butVal = digitalRead(butPin);
  if (butVal == 1 && butValOld == 0) {
    basePressure=0;
    oled.clearDisplay();
    oled.setCursor(0,12);
    oled.setTextSize(1);
    oled.setTextColor(WHITE);
    oled.println("WAIT . . .");
    oled.display();
    for (int i=1;i<=100;i=i+1){
      basePressure=basePressure + BP.readPressure();
    }
    basePressure = basePressure/100;
    haveBase = true;
  }
  butValOld = butVal;
  if (haveBase == true) {
    HeightNow = findHeight(basePressure);
    Height = .95 * Height + .05 * HeightNow;
    feet = Height;
    inches = (Height - feet) * 12; 
    oled.clearDisplay();
    oled.setCursor(0, 12);
    oled.setTextColor(WHITE);
    oled.setTextSize(1);
    oled.print(feet);
    oled.print(" Ft ");
    oled.print(inches);
    oled.println(" In");
    oled.setTextSize(1);
    oled.println("Place the Deluxe ");
    oled.println("HeightOmatic at");
    oled.println("Base Location, and");
    oled.println("Press Go!");
    oled.display();
    delay(10);
  }
}

float findHeight(float p0) {
  float d;
  float T0 = 288.15;
  float L = .0065;
  float R = 8.3144598;
  float M = .0289644;
  float g = 9.8;
  float pH;
  pH = BP.readPressure();
  float c = R * L / (M * g);
  d = T0 / L * (1 - pow((pH / p0), c));
  d = d * 3.28084;
  return d;
}

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102

103

104

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106

#include <SPI.h>

#include <Wire.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

#include <Adafruit_BMP085.h>

Adafruit_BMP085 BP;

bool BMPconnected;

bool haveBase = false;

int butPin = 2;

int butVal = 1;

int butValOld = 1;

float basePressure;

float Height = 0;

float HeightNow = 0;

int feet;

int inches;

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:

Serial.begin(9600);

pinMode(butPin, INPUT_PULLUP);

delay(250);

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.setCursor(0, 12);

oled.setTextColor(WHITE);

oled.setTextSize(1);

oled.println("Place the Deluxe ");

oled.println("HeightOmatic at");

oled.println("Base Location, and");

oled.println("Press Go!");

oled.display();

}

void loop() {

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

butVal = digitalRead(butPin);

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

basePressure=0;

oled.clearDisplay();

oled.setCursor(0,12);

oled.setTextSize(1);

oled.setTextColor(WHITE);

oled.println("WAIT . . .");

oled.display();

for (int i=1;i<=100;i=i+1){

basePressure=basePressure + BP.readPressure();

}

basePressure = basePressure/100;

haveBase = true;

}

butValOld = butVal;

if (haveBase == true) {

HeightNow = findHeight(basePressure);

Height = .95 * Height + .05 * HeightNow;

feet = Height;

inches = (Height - feet) * 12;

oled.clearDisplay();

oled.setCursor(0, 12);

oled.setTextColor(WHITE);

oled.setTextSize(1);

oled.print(feet);

oled.print(" Ft ");

oled.print(inches);

oled.println(" In");

oled.setTextSize(1);

oled.println("Place the Deluxe ");

oled.println("HeightOmatic at");

oled.println("Base Location, and");

oled.println("Press Go!");

oled.display();

delay(10);

}

float findHeight(float p0) {

float d;

float T0 = 288.15;

float L = .0065;

float R = 8.3144598;

float M = .0289644;

float g = 9.8;

float pH;

pH = BP.readPressure();

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

d = T0 / L * (1 - pow((pH / p0), c));

d = d * 3.28084;

return d;

}

Arduino

Measure Altitude with an Arduino Project

February 13, 2025 admin

In this video lesson I show you how you can create a project for measuring altitude using an arduino and a BMP180 Pressure Sensor. We go through the physics, math, circuit and coding to make this project work. For our example, we are using a GY-87 module, which has a BMP180 sensor on it. If you are using a BMP180 sensor directly, it should work the same. For your convenience, this is the circuit schematic we will be using:

Schematic for connecting the GY-87 module to the Arduino

For your convenience, the code we developed in the video lesson above is included below. Enjoy!

#include <Adafruit_BMP085.h>

Adafruit_BMP085 BP;
bool BMPconnected;
bool haveBase = false;

float basePressure;
float Height = 0;
float HeightNow=0;

void setup() {
  // put your setup code here, to run once:
  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.");
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  if (haveBase==false){
    Serial.println("Place Device at Base, Enter Go:");
    while (Serial.available()==0){

    }
    basePressure=BP.readPressure();
    haveBase = true;
  }
  HeightNow = findHeight(basePressure);
  Height= .95*Height + .05*HeightNow;
  Serial.print(5);
  Serial.print(",");
  Serial.print(-5);
  Serial.print(",");
  Serial.print(HeightNow);
  Serial.print(",");
  Serial.println(Height);

  delay(10);

}

float findHeight(float p0){
  float d;
  float T0 =288.15;
  float L =.0065; 
  float R = 8.3144598;
  float M = .0289644;
  float g = 9.8;
  float pH;
  pH=BP.readPressure();
  float c=R*L/(M*g);
  d = T0/L*(1 - pow((pH/p0), c ));
  d = d * 3.28084;
  return d;
}

#include <Adafruit_BMP085.h>

Adafruit_BMP085 BP;

bool BMPconnected;

bool haveBase = false;

float basePressure;

float Height = 0;

float HeightNow=0;

void setup() {

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

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.");

}

void loop() {

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

if (haveBase==false){

Serial.println("Place Device at Base, Enter Go:");

while (Serial.available()==0){

}

basePressure=BP.readPressure();

haveBase = true;

}

HeightNow = findHeight(basePressure);

Height= .95*Height + .05*HeightNow;

Serial.print(5);

Serial.print(",");

Serial.print(-5);

Serial.print(",");

Serial.print(HeightNow);

Serial.print(",");

Serial.println(Height);

delay(10);

}

float findHeight(float p0){

float d;

float T0 =288.15;

float L =.0065;

float R = 8.3144598;

float M = .0289644;

float g = 9.8;

float pH;

pH=BP.readPressure();

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

d = T0/L*(1 - pow((pH/p0), c ));

d = d * 3.28084;

return d;

}

Technology Tutorials

Tag Archives: BMP180

Portable Arduino Weather Station Project

Portable Arduino Barometric Weather Station

Arduino Weather Barometer

Portable Altimeter Project with Arduino

Measure Altitude with an Arduino Project

Making The World a Better Place One High Tech Project at a Time. Enjoy!