Tag Archives: GY-87

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

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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#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 Air Pressure with the Arduino and BMP180 Pressure Sensor

February 6, 2025 admin

In this video lesson we explain how to use the BMP180 to measure barometric pressure and temperature. We explain basic concepts of what pressure is, and we show how the BMP180 measures pressure. The circuit schematic we use is shown here:

Schematic for connecting the GY-87 module to the Arduino

For your convenience, this is the code we developed in the video for measuring Temperature and Barometric Pressure.

#include <Adafruit_BMP085.h>
Adafruit_BMP085 BP;

float Pressure;
float tempC;
bool BMPconnected;
void setup() {
  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() {
  tempC = BP.readTemperature();
  Pressure = BP.readPressure();
  Serial.println("READINGS ------------");
  Serial.print("Temperature = ");
  Serial.print(BP.readTemperature());
  Serial.println(" *C");

  Serial.print("Pressure = ");
  Serial.print(Pressure);
  Serial.println(" Pascals");
  Serial.println("");

  delay(1000);
}

#include <Adafruit_BMP085.h>

Adafruit_BMP085 BP;

float Pressure;

float tempC;

bool BMPconnected;

void setup() {

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() {

tempC = BP.readTemperature();

Pressure = BP.readPressure();

Serial.println("READINGS ------------");

Serial.print("Temperature = ");

Serial.print(BP.readTemperature());

Serial.println(" *C");

Serial.print("Pressure = ");

Serial.print(Pressure);

Serial.println(" Pascals");

Serial.println("");

delay(1000);

}

Technology Tutorials

Tag Archives: GY-87

Portable Arduino Barometric Weather Station

Arduino Weather Barometer

Portable Altimeter Project with Arduino

Measure Air Pressure with the Arduino and BMP180 Pressure Sensor

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