Connecting The BMP085 In Arduino With Python Coding

Introduction

In this article I will explain about connecting the BMP085 in Arduino and Python. In Arduino it will be used to see the temperature measurement in the Serial monitor. But in Python it will display in the run module.

 

Parts Of Lists

HardWareParts

• Arduino Uno
• BMP085
• Hook up wires
• Bread Board.

Software Required

• Arduino IDE 
• Python 2.7.11

Connection

Connection From ArduinoUno To BMPO85 Sensor

Sensor	Board
Gnd	Gnd
Vin	5v
SDA	A3
SCL	A4

Progarmming

Program Of Arduino

#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 tempC;  // Variable for holding temp in C
float tempF;  // Variable for holding temp in F
float pressure; //Variable for holding pressure reading

void setup(){
Serial.begin(9600); //turn on serial monitor
mySensor.begin();   //initialize mySensor
}

void loop() {
tempC = mySensor.readTemperature(); //  Read Temperature
tempF = tempC*1.8 + 32.; // Convert degrees C to F
pressure=mySensor.readPressure(); //Read Pressure

Serial.print("The Temp is: "); //Print Your results
Serial.print(tempF);
Serial.println(" degrees F");
Serial.print("The Pressure is: ");
Serial.print(pressure);
Serial.println(" Pa.");
Serial.println("");
delay(250); //Pause between readings.
}

Program Of Python

import serial # import Serial Library
import numpy  # Import numpy
import matplotlib.pyplot as plt #import matplotlib library
from drawnow import *

tempF= []
pressure=[]
arduinoData = serial.Serial('com11', 115200) #Creating our serial object named arduinoData
plt.ion() #Tell matplotlib you want interactive mode to plot live data
cnt=0

def makeFig(): #Create a function that makes our desired plot
    plt.ylim(80,90)                                 #Set y min and max values
    plt.title('My Live Streaming Sensor Data')      #Plot the title
    plt.grid(True)                                  #Turn the grid on
    plt.ylabel('Temp F')                            #Set ylabels
    plt.plot(tempF, 'ro-', label='Degrees F')       #plot the temperature
    plt.legend(loc='upper left')                    #plot the legend
    plt2=plt.twinx()                                #Create a second y axis
    plt.ylim(93450,93525)                           #Set limits of second y axis- adjust to readings you are getting
    plt2.plot(pressure, 'b^-', label='Pressure (Pa)') #plot pressure data
    plt2.set_ylabel('Pressrue (Pa)')                    #label second y axis
    plt2.ticklabel_format(useOffset=False)           #Force matplotlib to NOT autoscale y axis
    plt2.legend(loc='upper right')                  #plot the legend


while True: # While loop that loops forever
    while (arduinoData.inWaiting()==0): #Wait here until there is data
        pass #do nothing
    arduinoString = arduinoData.readline() #read the line of text from the serial port
    dataArray = arduinoString.split(',')   #Split it into an array called dataArray
    temp = float( dataArray[0])            #Convert first element to floating number and put in temp
    P =    float( dataArray[1])            #Convert second element to floating number and put in P
    tempF.append(temp)                     #Build our tempF array by appending temp readings
    pressure.append(P)                     #Building our pressure array by appending P readings
    drawnow(makeFig)                       #Call drawnow to update our live graph
    plt.pause(.000001)                     #Pause Briefly. Important to keep drawnow from crashing
    cnt=cnt+1
    if(cnt>50):                            #If you have 50 or more points, delete the first one from the array
        tempF.pop(0)                       #This allows us to just see the last 50 data points
        pressure.pop(0)

Explanation

In this article  I  will explain about how the  BMP085 can be used to see the temperature level. In Arduino it will be displayed in the serial monitor but in Python I have used the matlab plot.

The matplot software is used to display the higher and lower levels of the temperature. Click the software below and download the software.

http:/pip.pypa.io/en/learning/installing. 

In Python write the code and click the run module or f5 to see the output.

In Python the data and the code will be read from Arduino because we have given the Arduino port in Python.The matlab plot can plot the temperature in the current level.

Output

 
Figure 1 : Output