Juan Santacruz

This week I work in a system thay sens a signal (potentiometer), a data signal send through Arduino Mega to Raspberry Pi. In Raspberry Pi, datais storaged in a base date () and will see at time in a window.

SENSOR

I use a Potentiometer in Analog pin in Arduino Mega.

ARDUINO MEGA

This is the sensor conections in Arduino mega

Arduino Program:


    const int analogInPin = A0;  // Analog input pin that the potentiometer is attached to 
    const int analogOutPin = 9; // Analog output pin that the LED is attached to
    int sensorValue = 0;        // value read from the pot.
    int outputValue = 0;        // value output to the PWM (analog out)

    void setup() {
      // initialize serial communications at 9600 bps:
      Serial.begin(9600);
    }

    void loop() {
      // read the analog in value:
      sensorValue = analogRead(analogInPin);
      // map it to the range of the analog out:
      outputValue = map(sensorValue, 0, 1023, 0, 255);
      // change the analog out value:
      analogWrite(analogOutPin, outputValue);

      // print the results to the serial monitor:
      Serial.print("{\"sensor\":");
      Serial.print(sensorValue); 
      Serial.println("}\n");

      // wait 2 milliseconds before the next loop
      // for the analog-to-digital converter to settle
      // after the last reading:
      delay(3000);
    }

RASPBERRY PI V3

See about Raspberry Pi v3 here

To install Software you need:

    1. Download .img Raspbian from its Web page
    2. SD card 16GB or higer
    3. Win32DiskImager program for burn .img image to SD card

Conect to Screeen by ethernet

I followed tutorial from here

1. Share internet in Local Area Adapter WiFi. In Local Area Adapter appear automatic Ip number

2. Conect your Raspberry and find it with IpScan Software Download

3. Open IpScan and find Raspberry

4. Take the SD card from Raspberry and insert in PC SD card. Open Terminal and write: echo>E:\ssh. E:\ is disk mount letter in your PC

5. Install MobaXterm software Download

6. Put Raspberry name in SSH and click OK

7. Login as user: pi; password: raspberry

8. Write startlxde to enter in desktop

9. For to VNC access follow this Tutorial

9.1. In terminal:

    sudo apt-get install tightvncserver

    vncserver :1 -geometry 1280x800 -depth 16 -pixelformat rgb565

        1 (is desktop number)
        geometry (width screen recomended use from your PC)

9.2. You can install chrome aplication for VNC conections

9.2.1 When you connected, use IP number + :1 (desktop number) like this: 192.168.137.237:1

Start Raspberry Pi and follow this steps in lxterminal

    1. sudo addgroup www-data
    2. sudo usermod -a -G www-data www-data
    3. sudo apt-get update
    4. sudo apt-get install apache2 php5 libapache2-mod-php5
    5. sudo /etc/init.d/apache2 restart
    6. sudo ifup lo
    7. sudo apt-get install mysql-server mysql-client php5-mysql phpmyadmin
    8. sudo nano /etc/php5/apache2/php.ini
    9. extension=mysql.so     //Before “Dynamics Extensions”: line
    10. sudo ln -s /etc/phpmyadmin/apache.conf /etc/apache2/conf-available/phpmyadmin.conf
    11. sudo /etc/init.d/apache2 reload
    12. sudo /etc/apache2/apache2.conf
    13. Include /etc/phpmyadmin/apache.conf //in the end (ctrl+x, y, enter)
    14. sudo /etc/init.d/apache2 (restart)
    15. Open a browser and past this text: localhost/phpmyadmin if server is run, web page admin will open in login

CREATE BASE DATA

When you create base data, is important create a incrementable "id" table for storage incrementate data.

1. Create New Database and name it.

2. Create a tables and name it. Select number of columns

3. Use atributes in Id table an Incrementable in Column "A_I"

4. Use atributes in data table

CREATE PYTHON PROGRAM

1. Change user to super user and install pyserial

apt-get install pyserial

2. Create in root directory a file.py and edit it with the program

      a. nano ejex.py
      b. Past the python program 

      c. execute with: python ejex.py

PYTHON PROGRAM


    #!/usr/bin/env python
     
    #!/usr/bin/env python
     
    import serial
    import json
    import MySQLdb
     
    arduino = serial.Serial('/dev/ttyACM0',9600)
    print arduino.readline()
    print arduino.readline()
    while True:
        character= arduino.readline()   
        MyJson = character
        db = MySQLdb.connect("localhost","root","root","Data")
        if character != '\n':
            try:
                data=json.loads(character)
                print data
                print data['sensor']
                curs = db.cursor()

                curs.execute("INSERT INTO axex(FECHA,EJEX)values(now(),"+str(data['sensor'])+")")
                db.commit()
            except ValueError:
                print ""
     
     arduino.close()

3. Rename database and variables

3. Execute python file

a. execute with: python ejex.py

3. Open Database and look in table axex results

ARDUINO AND PROCESSING

You can process data using Arduino and Processing software like this example

Arduino Program

    void setup() {
      // initialize the serial communication:
      Serial.begin(9600);
    }

    void loop() {
      // send the value of analog input 0:
      Serial.println(analogRead(A0));
      // wait a bit for the analog-to-digital converter
      // to stabilize after the last reading:
      delay(100);
    }

Processing Program


    import processing.serial.*;

    Serial myPort;        // The serial port
    int xPos = 1;         // horizontal position of the graph
    float inByte = 0;

    void setup () {
      // set the window size:
      size(400, 300);

      // List all the available serial ports
      // if using Processing 2.1 or later, use Serial.printArray()
      println(Serial.list());

      // I know that the first port in the serial list on my mac
      // is always my  Arduino, so I open Serial.list()[0].
      // Open whatever port is the one you're using.
      myPort = new Serial(this, Serial.list()[0], 9600);

      // don't generate a serialEvent() unless you get a newline character:
      myPort.bufferUntil('\n');

      // set inital background:
      background(0);
    }
    void draw () {
      // draw the line:
      stroke(127, 34, 255);
      line(xPos, height, xPos, height - inByte);

      // at the edge of the screen, go back to the beginning:
      if (xPos >= width) {
        xPos = 0;
        background(0);
      } else {
        // increment the horizontal position:
        xPos++;
      }
    }


    void serialEvent (Serial myPort) {
      // get the ASCII string:
      String inString = myPort.readStringUntil('\n');

      if (inString != null) {
        // trim off any whitespace:
        inString = trim(inString);
        // convert to an int and map to the screen height:
        inByte = float(inString);
        println(inByte);
        inByte = map(inByte, 0, 1023, 0, height);
      }
    }

VIDEO

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16. INTERFACE APPLICATION PROGRAMMING