Published June 10, 2019 © GPL3+

Barometer with Analog Scale (Ammeter)

An analog-style BMP180 barometer.

BeginnerFull instructions provided4,120

Things used in this project

Hardware components

Arduino UNO

Rotary potentiometer (generic)

Ampermeter 1mA

MyOctopus i2c Barometric Air Pressure Sensor BMP280

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Story

A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather.

The device described below contains Arduino and BMP085 sensor module and the pressure is displayed on an analogue ammeter, so the value of air pressure can be read very easily. When starting the device, the arrow deflect to the maximum and return to zero again and serves to calibrate the ammeter, which is connected through a potentiometer on the arduino.

Code as the entire device is very simple and takes a very short time for full implementation.

Тhe minimum and maximum values of the ABSOLUTE air pressure for given altitude are set in the code.Тhe scale is graded in relative pressure.

90135Hpa absolute = 980Hpa relative pressure for 700m altitude

and

95653Hpa absolute = 1040Hpa relative pressure for 700m altitude

You can find absolute/relative air pressure calculator at:

https://www.mide.com/pages/air-pressure-at-altitude-calculator

Code

code

#include "Wire.h"    // imports the wire library for talking over I2C 
#include "Adafruit_BMP085.h"  // import the Pressure Sensor Library
Adafruit_BMP085 mySensor;  // create sensor object called mySensor


float pressure; //Variable for holding pressure reading

int out=0;
int ANALOGPRESSURE=0;

void setup() 
{
pinMode(6, OUTPUT);

mySensor.begin();   //initialize mySensor

test();
}

void loop() {

pressure=mySensor.readPressure(); //Read Pressure
ANALOGPRESSURE=map (pressure,90135,95653,0,255);//Absolute values
analogWrite (6,ANALOGPRESSURE);
delay (20000);
}

void test() {
for (int i=1;i<=255;i++)
{
analogWrite (6, i);  
delay (20);
}
for (int i=255;i>=1;i--)
{
analogWrite (6, i);  
delay (20);
}
delay (1000);
}

Credits

Mirko Pavleski

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Barometer with Analog Scale (Ammeter)

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

schematic

Code

code

Credits

Mirko Pavleski

Comments

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Barometer with Analog Scale (Ammeter)

Barometer with Analog Scale (Ammeter)

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Schematics

schematic

Code

code

Credits

Mirko Pavleski

Comments

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