How to interface Arduino with RaspberryPi

How to interface Arduino with RaspberryPi

1. Download and install Arduino in Rpi

Open browser in raspberry pi and open the link below.

https://www.arduino.cc/en/Main/OldSoftwareReleases#previous

Then, download Linux ARM and extract it by command.

tar  -xvzf file name  

After extracting you will see new directory. Here I am using arduino-1.8.1 IDE. Then go to directory by using command.

cd arduino-1.8.1 

To run Arduino, use command in arduino-1.8.1 directory.

 ./arduino 

2. How to use libraries

To install any libraries in Arduino , simply download the library and paste in arduino--->libraries folder .

NOTE:- Make sure there is no ( - ) in library folder for ex (DHT-sensor). If there is any (-),rename it .

Now let's do one example of temperature sensor. To check whether its working or not.

Here, I am interfacing DHT11 temperature sensor with Arduino uno.

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Arduino Program

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#include "DHT.h"

#define DHTPIN 7 // what digital pin we're connected to

// Uncomment whatever type you're using!

#define DHTTYPE DHT11 // DHT 11

//#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321

//#define DHTTYPE DHT21 // DHT 21 (AM2301)

// Initialize DHT sensor.

DHT dht(DHTPIN, DHTTYPE);

void setup() {

Serial.begin(9600);

dht.begin();

}

void loop() {

// Wait a few seconds between measurements.

delay(2000);

// Reading temperature or humidity takes about 250 milliseconds!

int h = dht.readHumidity();

// Read temperature as Celsius (the default)

int t = dht.readTemperature();

Serial.print("Humidity: ");

Serial.print(h);

Serial.print("\t"); // for splitting

Serial.print("Temperature: ");

Serial.print(t);

Serial.print("\n"); // for new line

}

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Verify it and upload it to Arduino uno via Raspberry pi.Then open serial monitor .

We have verified its working ,now proceed to next step.

3. Store temperature data to database of raspberry pi .

Here I am assuming you already have created database in raspberry pi. If you dont know how to create database,check link below.

http://www.raspberry-projects.com/pi/software_utilities/web-servers/mysql

After that install the required libraraies.

Sudo apt-get install python-serial 

Sudo apt-get install python-mysqldb 

After installing libraries. Create a python script to store data from Arduino to Raspberry pi database.

Sudo nano name.py 

Program to be write in script

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import serial

import time

import MySQLdb as mdb

arduino = serial.Serial("/dev/ttyACM0") // make sure you write correct serial

arduino.baudrate=9600

data = arduino.readline()

time.sleep(2)

data = arduino.readline()

pieces =data.split("\t")

temperature = pieces[0]

humidity = pieces[1]

con = mdb.connect('localhost','root','password','database_name');

with con:

cursor =con.cursor()

cursor.execute("INSERT INTO table_name VALUES('',%s,%s

(temperature,humidity))

con.commit()

cursor.close()

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Run python script by command

python ./scriptname.py 

To run python script automatically after few seconds to update database ,we have to change crontab and save it . To open crontab ,write command.

Crontab –e 

After opening it ,write */1 * * * * python /home/pi/scriptname.py at the end .

After edit and save crontab. Reboot raspberry pi.

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Result

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NOTE:- ALL THE THINGS WORK ONLY WHEN TEMPERATURE SENSOR IS CONNECTED TO ARDUINO AND ARDUINO IS CONNECTED TO RASPBERRY PI SERIALLY.