Altitude | Technology Tutorials

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:

Height Sensor — Schematic to Create a Portable Arduino Elevation Measurement System

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.

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;

}

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:

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;

}

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

Technology Tutorials

Tag Archives: Altitude

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!