Category Archives: Arduino

In this video I show you how you can easily plot any graph or data onto any OLED display. We create a mathematical function which will map the raw data onto the screen. We demonstrate the function with a sin wave, but the function will work with any equation or data. This is the code which we developed in the video.

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

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

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

float xMin = 0;
float xMax = 2 * 3.1415;

float yMin = -1;
float yMax = 1;

float Pt = 0;
float Pb = 63;

float Pl = 0;
float Pr = 127;

float pi = 3.14159265;

int numPoints = 128;

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

int j=0;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  oled.clearDisplay();
  oled.display();
}
void loop() {
  // put your main code here, to run repeatedly:

  for (int i = 0; i < numPoints; i = i + 1) {
    rawXdata[i] = i * (2 * pi / 127);
    rawYdata[i] = sin(rawXdata[i]);
    Serial.println(rawYdata[i]);
    delay(100);
  }
normData();
plotGraph();
oled.display();
}

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);
  for (int i=0;i<numPoints-1;i=i+1){
  oled.drawLine(normXdata[i],normYdata[i],normXdata[i+1],normYdata[i+1],WHITE);
  }
}

#include <SPI.h>

#include <Wire.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

float rawXdata[128];

int normXdata[128];

float rawYdata[128];

int normYdata[128];

float xMin = 0;

float xMax = 2 * 3.1415;

float yMin = -1;

float yMax = 1;

float Pt = 0;

float Pb = 63;

float Pl = 0;

float Pr = 127;

float pi = 3.14159265;

int numPoints = 128;

int screenWidth = 128;

int screenHeight = 64;

int oledReset = -1;

#define SCREEN_ADDRESS 0x3C

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

int j=0;

void setup() {

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

Serial.begin(115200);

oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);

oled.clearDisplay();

oled.display();

}

void loop() {

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

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

rawXdata[i] = i * (2 * pi / 127);

rawYdata[i] = sin(rawXdata[i]);

Serial.println(rawYdata[i]);

delay(100);

}

normData();

plotGraph();

oled.display();

}

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);

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.

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.

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:

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;

}

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:

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;

}

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:

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

Category Archives: Arduino

Plot any Data or Graph on any OLED

Arduino Weather Barometer

Portable Altimeter Project with Arduino

Measure Altitude with an Arduino Project

Measure Air Pressure with the Arduino and BMP180 Pressure Sensor

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