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Generally Raspberry PI is connected to a Router as an individual computer.In case you do not have access to your Router you can very well connect PI to Laptop through an ETHERNET STRAIGHT Cable.

The available RJ45 cable in the market is mostly STRAIGHT cable & not CROSS OVER one.

Before connecting the PI to Laptop , open your Network & sharing center & click on your Internet connection.Mine is on Wireless Network

 

Image 4

On the next screen click on the  properties button.

 

Image 5

Under SHARING tab Tick mark “Allow other network users…..”

Click OK to enable Network SHARING.

Image 6

Now let us enable SECURED SHELL – SSH on Raspberry PI OS , so that it can be accessed over network.

This can be done by connecting RPI to a HDMI TV & a keyboard.

Under terminal open RASPI-CONFIG & enable SSH under Advanced options.

But in this post I consider a Headless mode , presuming that you do not have access to a TV or keyboard.You need a CARD READER for this purpose.

Place the SD card with Raspbian OS on to the card reader & plug it to ypur laptop.

Note down the Drive letter allotted.Here it is I:\  in my case

 

Image 1

Run CMD & type in following

echo >I:\ssh

Now a file named ssh without any extension is created under \boot.

Image 2

 

Image 3

While PI is booted up then , it looks out for the file named ssh.

If it finds one , it enables SSH & then deletes the file you created.

This is how SSH is enabled in the new Raspbian OS.By default SSH is disabled in new OS for security reasons.

Plug the SD card on to PI & connect the ETHERNET cable to Laptop’s RJ45 slot.

Power up the PI to see a new Unidentified network .

Image 7

Click on that new Local Area Connection that appears & then click properties.

On the next screen , double click on Internet Protocol Version 4(TCP/IPv4)

 

Image 8

Now you see the IP address of the new Network created.

Here it is 192.168.137.1 which is the GATEWAY IP of the new Network.

PI will be allotted IP within this range 192.168.137.xxx

Image 10

To know the IP of RPI we make use of ADVANCED IP SCANNER

Download from here & install the scanner

http://filehippo.com/download_advanced_ip_scanner/download/a518016bdff73f05b5f25826e519a493/

Open the IP Scanner program & type in the Range to scan as 192.168.137.1 to 192.168.137.254

Image 11

Click on the scan button.

The IP scanner will detect the Raspberry PI & displays its IP along with host name & MAC address.

The host name is

raspberrypi.mshome.net   & the IP is

192.168.137.240

Image 12

You can use either the host name or the IP to access the PI.

We make use of an X Forwarding software called MOBAXTERM for a Graphical Interface.

You can use XMING server , but a separate SSH client like PUTTY is needed for that.

MOBAXTERM is a standalone freeware with an inbuilt SSH Client.

http://mobaxterm.mobatek.net/download-home-edition.html

Download the X Server

Image 13

Fire up the MobaXterm_Personal application.

Image 14

Click on SESSION & then SSH

Image 15

 

Under Remote Host type in the host name of RPI   raspberrypi.mshome.net

 

hostname

or you can use the IP address of PI we obtained from IP Scanner earlier.

Image 16

Now you get the login window.

Login username is pi & password is raspberry

Image 17

 

Now you are logged into Raspberry PI & you get the ~$ prompt

Image 18

 

To open Graphical interface , type in

startlxde

 

Image 19

 

You get a warning message SSH is ON .

Image 20

Click OK to see the DEBIAN SWIRL desktop.

 

Image 21

 

Image 22

 

Image 24

 

Image25

 

To enable WIFI & internet access , watch this video :

 

 

cooltext753793315  cooltext753790696

 

 

 

 

 

 

 

 

 

 

Image 13

The older XBEE modules S2 & S1 are not capable of communicating  with each other. S2 can talk only to S2 , S1 with S1 .You cannot mix the modules.

The new XBEE S2C is capable of communicating with S2 as well as S1 modules.

For S2C to S2C configuration you can check out the previous post Here

XBEE S2C with S2

Place an XBEE S2C module on USB adapter & plug on to USB port of your Laptop.Open the XCTU & search for the radio.Once the radio is detected , select it & load the settings.

Image 2

 

The product family is XB24C  & the Function set is ZIGBEE TH Reg.  (Through Hole Regular).

Image 3

The PANID is set to 1234.

The same PANID to be set for the other Radio also.The Destination LOW address is FFFF which makes the Radio to BROADCAST mode.

AP is TRANPARENT mode which is AT mode

NI is Node Identifier which you can name it as COORDINATOR.

Image 4

 

Image 5

Click on the PENCIL icon on top to WRITE the settings made.

Now plug the S2 module on another USB adapter & plug it to other USB port .

Search for the Radio & select it.

Image 6

Load the settings & click on the UPGRADE FIRMWARE button.

Select the product family as XB24-ZB & the Function set as ZIGBEE ROUTER AT

Image 7

 

Click on FINISH button to complete the upgrade action.

 

Image 8

 

Image 9

 

Set the PANID as 1234 , same as that of COORDINATOR.

JV is ENABLED , so that the radio joins Coordinator on power on.

DL is set to 0 , which is the default address of coordinator.

Image 10

Now the S2 module is configured as Router.

Leave this module on the XCTU & close the Coordinator module.

Start another instance of XCTU window & search for the COM port , select the Coordinator Radio.

Place the XCTU windows side by side.Coordinator to the left & Router to the Right.

Image 11

Click on the Terminal icon on the top & then click the SERIAL connect icon.The open Serial icon now changes to a closed one.Do this on both the windows.

Image 12

Type in some message inside S2C window which will be received by the Router.Both way communication is possible (Full Duplex)

 

Image 13

S2C with S1

Now pull out the S2 module from USB adapter & replace it with S1 module.

S2C is left on the same USB port.

S2C module is to be upgraded Firmware 802.15.4TH .

Click on the Upgrade Firmware icon & select XB24C –> 802.15.4 TH & the latest version.

Click Finish to upgrade.

Image 14

 

The CHANNEL is left to default C.

PAN ID is 1234 , DL is FFFF

MY address is 0

CE is COORDINATOR ENABLE

 

Image15

 

Now start another instance of XCTU & select the COM port where S1 is plugged on.

Select the Radio & load the settings.

S1 belongs to Function set XB24  –>802.15.4

Image16

 

The Channel is set as C

& PAN ID 1234   same as that of Coordinator

DL –> 0  MY address is 1 & CE is set to END DEVICE.c

Image 17

Click on WRITE button to save the changes made.

Place both the XCTU windows side by side.

Click on TERMINAL icon & then SERIAL Lock on both the windows.

Test for communication by typing some message which appears on the other window.

Image 50

Watch this Support Video  :

 

 

 

DIGI International has recently introduced the new ZIGBEE S2C Module .The previous S2 & the traditional S1 both are discontinued.

The new module is powerful with both UART & SPI communication .

Operating frequency band is The industrial, scientific and medical (ISM) radio band
ISM 2.4 – 2.5 GHz

It utilizes Silicon labs EM357 transceiver

The Module is faster and has more RAM & flash memory with much reduced power consumption.

Increases the mesh capabilities & consumes under 1 micro amp sleep current.

Interface options : UART 1 Mb/s maximum (burst)  , SPI 5 Mb/s maximum (burst)

Here is the comparison chart of S1 , S2 & S2C .The Indoor/Outdoor range of S2C has also increased much more as the transmit output power is  double.Also it works on supply voltage from 2.1v to 3.6v DC.

compare

 

Here are the device types of XBEE :

Device types

ZigBee defines three different device types: coordinator, router, and end device.

clip_image001 Coordinator

ZigBee networks always have a single coordinator device. This device Starts the network, selecting the channel and PAN ID.Distributes addresses, allowing routers and end devices to join the network.Buffers wireless data packets for sleeping end device children.

The coordinator manages the other functions that define the network, secure it, and keep it healthy. This device cannot sleep and must be powered on at all times.

clip_image002 Router

A router is a full-featured ZigBee node. This device can join existing networks and send, receive, and route information. Routing involves acting as a messenger for communications between other devices that are too far apart to convey information on their own.

Can buffer wireless data packets for sleeping end device children. Can allow other routers and end devices to join the network.Cannot sleep and must be powered on at all times.May have multiple router devices in a network

clip_image003 End device

An end device is essentially a reduced version of a router. This device can join existing networks and send and receive information, but cannot act as messenger between any other devices.Cannot allow other devices to join the network.

Uses less expensive hardware and can power itself down intermittently, saving energy by temporarily entering a nonresponsive sleep mode.Always needs a router or the coordinator to be its parent device. The parent helps end devices join the network and stores messages for them when they are asleep.

ZigBee networks may have any number of end devices. In fact, a network can be composed of one coordinator, multiple end devices, and zero routers.

Modes of operation
The XBee ZigBee RF Module is in Receive Mode when it is not transmitting data. The device
shifts into the other modes of operation under the following conditions:
— Transmit Mode (Serial data in the serial receive buffer is ready to be packetized)
— Sleep Mode
— Command Mode (Command Mode Sequence is issued, not available when using the SPI port)

Now let us practically see how to configure the Radio S2C. For communication one of the Radios to be configured as COORDINATOR & the other one as Router.

The Product family of S2C is  XB24C  (the previous S2 module belongs to XB24-ZB)

These S2C modules should be able to communicate with older modules, so long as they are all running compatible firmware (i.e. DigiMesh, ZB, etc..)

Following is the pin configuration of S2C.

S2C_PINS

 

To configure the XBEE you need an USB XBEE Adapter which can be easily connected to the USB port of your PC.

USB

 

In case you do not have this USB board , you can use your Arduino board as USB-UART. For this you need to connect RST of Arduino to GND.This bypasses the bootloader of Arduino & the board can be used for Serial communication.Remember to connect Rx to Rx , Tx to Tx (straight & NOT reverse connection) between Arduino & XBEE while configuring.

You can watch this video on how to use Arduino to configure XBEE

https://www.youtube.com/watch?v=wtal7SWZek0

 

Let us start with the configuration.Plug the S2C modules on to the USB adapters & connect to USB ports of your PC.

Open the new XCTU Software .S2C can be configured with this new XCT. The classic old XCtu does not support the S2C module.

Click on the SEARCH icon on top to detect the USB ports.

A list of active USB COM ports will be displayed.

Select the COM ports where you’ve connected the USB adapters.To confirm you can verify your DEVICE MANAGER for the proper COM ports.

In my case one of the USB adapter is allotted COM3 & the other one COM31.

Image 1

Click on NEXT & accept the default PORT PARAMETERS .

96008N1 is the default.  9600 is the BAUD RATE , 8 Data Bits, No Parity & 1 Stop bit.

Image 2

Click on FINISH .

The XCTU scans the USB ports selected & lists the RADIOs found with their unique 64 bit address.

Image 3

Select both the devices & click ADD SELECTED DEVICES.

Now both the Radios appear on the left pane.

Image 4

Let us configure the RADIO at COM3 as COORDINATOR first.

For this click on the COM3 RADIO to load the module settings.

 

Image 5

Once the parameter settings are loaded you can see that the product family is XB24C  (in case of old S2 it is XB24-ZB & of S1 is 802.15.4)

The function set of Firmware is ZIGBEE TH Reg , the Reg stands for Regular & not PRO. TH stands for THROUGH HOLE & not SMD.

Image 6

First thing is to set the PAN ID of the Network. This can be from 0 to FFFF hex.In my case I’m setting it to 1234.The other Radios also to be set in the same PAN ID.

Scroll down further & Enable the CE (Coordinator Enable)

 Image 7

The Destination address DH is left to default 0.

The Destination Address DL is set to hex FFFF which makes the Radio work on BROADCAST mode, so that it can communicate with all Radios in the same PANID.

The Node Identifier can be given any name like “Coordinator”.This naming  is optional.

Image 11_1

Click on the PENCIL icon on top to WRITE the changes made.

Image 8

 

Now let us configure the second Radio as ROUTER.

Click on the second Radio on the left pane to load the settings.

Image 12

The Router setting is quite simple.

Enter the PANID as 1234 , same as that of Coordinator.

Image 13

 

JV CHANNEL VERIFICATION is Enabled

CE Coordinator is DISABLED

Destination Address DL is left to default 0 . (0 is the default address of Coordinator)

rout1

 

rout2

Click on WRITE button to save the changes made.

Image 14

The modules are paired & ready for communication.

Now let us test the communication.On the XCTU window delete the second Radio .Click on the first Radio to load the settings.

Leaving the XCTU window open , start another instance of XCTU &position it to the left of the previous window.

Image 15

Click on the Search button on the new instance of XCTU & select the second Radio .

Image 16

Click on the Radio selected to load the settings.

Image 17

Now the ROUTER Radio is on the left side & the COORDINATOR Radio to the Right.

Image 18

Click the TERMINAL icon on both the windows to enter Terminal mode.

Image 19

Click on the SERIAL CONNECTION icon on both the windows to enter the serial connection mode.

Image 20

You can see the SERIAL Icon in LOCK mode & the AT CONSOLE Status changes to CONNECTED.

Now you can type any message inside console log window & see that received on the other Radio.The transmit message is in BLUE & received message in RED.

Image 21

802_1

Once the Function set is selected , click on FINISH to load the firmware.

802.15.4 firmware is like that of our classic S1 module.But setting is slightly different.

CH channel can be left to default C

PANID to be selected , say 1234 ( the other Radio to be on same ID)

DL address is FFFF

CE coordinator enable for first Radio

802_2

For the second Radio , to be set as END device

CH Channel C

PAN ID 1234 , same as Coordinator

MY address is 1 ( the coordinator MY is 0)

CE is set to END device

802_3

 

Click on WRITE button & test the modules for communication.

In this 802.15.4 Firmware POINT TO POINT communication only is possible & NO MESH Networking.

In a nutshell, the new X2C module is powerful & can work as S2 or the old S1 module.

Watch this support video :

cooltext753793315cooltext753790696

 

In the previous post we’ve seen how to program ESP8266 using Arduino IDE by installing the Boards Manager.

This post is on using the powerful ESP8266 WiFi Library which is automatically installed while using the Boards Manager.When you proceed with the  board package for the ESP8266,as explained in previous post, the ESP8266 WiFi library is automatically installed for you.

             Now, any time you want to use the classes and the functions from that ESP8266 WiFi library,  use the Include statement at the top of the program first, followed by the header name

#include <ESP8266WiFi.h>

at the starting of Arduino code & start using the Classes associated with this library.

ESP8266 WiFi library is designed after the the standard Arduino WiFi library but has even more functionality than the standard Arduino library .The standard Arduino WiFi library is used for the WiFi shield or with the Arduino boards like YUN with inbuilt WiFi.

With the introduction of ESP8266 , the WiFi functionality has become much cheaper & easy to use.

The WiFi library has many classes that you can use. Each class has functions in it that are specific to that class. There’s the WiFi class, the IP address class, the server class, the client class and the UDP class.

 

class1

 

In this post we’re going to explore the WiFi class & its functions.

The WiFi class allows to establish a connection with an access point.

What’s cool about the WiFi class is that we don’t  have to create an instance of this class. We can  go ahead and start using it. It’s like the serial library of Arduino. We don’t need to create an instance of the serial library.

class2

 

First Function of the library is WiFi.begin().

The usage of this function is similar to our Serial.begin().

Just like Serial.begin() , we use WiFi.begin() .WiFi.begin() requires 2 strings as arguments. You need to pass the SSID and the password of the Access point you wish to connect.You need to pass the arguments as character arrays or strings with a lower case s.

WiFi.begin(ssid,pass);

The possible return values are

WL_CONNECTED      after successful connection is established with the Access Point

WL_IDLE_STATUS       when Wi-Fi is in process of changing between statuses

WL_NO_SSID_AVAIL     in case configured SSID cannot be reached

WL_CONNECT_FAILED  if password is incorrect

WL_DISCONNECTED        if module is not configured in station mode

 

The status function in the WiFi class, doesn’t take any arguments but it returns stuff depending on the status of the network that you’re connected to.

Usually, first, you call WiFi.begin, you pass the SSID and the password because you’re trying to establish a connection with the network. Then, what you do is you wait in a loop until WiFi.status returns the value WL_CONNECTED.

——————————

WiFi.begin(ssid,password);

while (WiFi.status() != WL_CONNECTED)

{

delay(500);

Serial.print(“.”);

}

——————————

 

WiFi.SSID();

WiFi.SSID doesn’t take any arguments but it returns the name of the SSID that you’re connected to.

 

WiFi.RSSI()

Returns the current signal strength in  dB

 

WiFi.scanNetworks()

Returns the number of discovered networks.It will not list the network names , but returns the number of networks.

WiFi.macAddress()

Returns the MAC address of the ESP device

There is a specific function available to print out key Wi-Fi diagnostic information:

WiFi.printDiag(Serial);

Here is a sample sketch to demonstrate the WiFi library.

—————————————————-

#include <ESP8266WiFi.h>

void setup()
{
  Serial.begin(115200);
  Serial.println();

//disconnect any previous connections
  WiFi.disconnect();
  delay(1000);

//scan for number of nearby networks & print SSIDs

  Serial.print("Nearby networks found  :");
  Serial.println(WiFi.scanNetworks());
  delay(500);

Serial.println("List of surrounding Network SSIDs…:");
  int n = WiFi.scanNetworks();
  for (int i = 0; i < n; i++)
{
  Serial.println(WiFi.SSID(i));
}
  Serial.println();

//connect to preferred SSID
  
  WiFi.begin("SARAVANA-ACT", "mypass123");

  Serial.println("Connecting");
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println();

// print SSID name,local IP allotted ,MAC address & signal strength

  Serial.println();
  Serial.print("Connected to SSID          : ");
  Serial.println(WiFi.SSID());

  Serial.print("IP address allotted to ESP : ");
  Serial.println(WiFi.localIP());
 
  Serial.print("MAC Address of ESP         : ");
  Serial.println(WiFi.macAddress());

  Serial.print("Signal strength is         : ");
  Serial.println(WiFi.RSSI());

  }

void loop()
{
}

——————————————————–

The screenshot shows the result in the serial monitor of Arduino IDE

scan3

 

The Client & Server classes & their methods are shown in screen shots below :

class3

 

 

class4

Download PDF tutorial file for the WiFi library from

https://www.gitbook.com/download/pdf/book/krzychb/esp8266wifi-library

 

cooltext753793315   cooltext753790696

The ESP8266 by itself hosts a 32 bit Microcontroller on it & you can now program your ESP using Arduino IDE. Best part is that NO Arduino board is required.You can upload your code from Arduino IDE , as if you were upgrading the Firmware on ESP.

You can pretty much write any code  for an Arduino and run it on the ESP8266. Of course there is a limit to the I/O on some of the modules, but the Flash on the ESP-12E (Black) module is 4MB and the RAM is 80kB! Add to that the 80MHz 32-bit processor and you have a pretty impressive little cute Arduino.

A sample Blink example program on the ESP8266 turns out to be around 225kB, but that includes the core code.So it’s advisable to use an ESP8266 with more FLASH Memory.Generally the BLACK ones are with higher memory than the Blue ones.The new ESP12E has a Flash of whooping 4MB !!  The Arduino UNO has just 32k Flash & Mega 256k.

esp_blue_black

 

esp12e_bl_black

 

Program uploading is done at 115,200 Baud, the default for the module. But It still takes a while to upload a sketch to the module , unlike a regular Arduino.

To begin, you must install the ESP8266 board files in the Arduino IDE.

That is easy enough to do. Make sure that your Arduino IDE is latest

Open the Arduino preferences from File  —> Preferences

Image 1

 

Add the following URL to the “Additional Boards Manager URLs” seen at the bottom of Preferences Window

http://arduino.esp8266.com/stable/package_esp8266com_index.json

Image 2

 

Click OK to close the Preferences Window.

Click on TOOLS –. BOARDS—> BOARDS MANAGER

Image 4

When the Boards Manager opens, scroll to the bottom. You should see the esp8266 entry.

Select the latest version & then click on INSTALL button.

Image5

It takes a while to download & install .

 

Image 6

Once installation is over , close the IDE & start again,

Under Tools –> Boards you can now see a new list of ESP8266 Modules.

Image 7

Its time to test some example code.

While using the ESP module make sure that

Power source is 3.3v DC

CH_PD & RESET pins pulled HIGH through resistor.

You can use a development board available at

http://www.alselectro.com/wifi-esp8266-esp-12-demo-board.html

Image26

An LED is connected to GPIO4 through a resistor.

Image 22

An USB-TTL board is used to connect ESP with USB port of PC.

Rx of USB-TTL board goes to Tx of ESP board

Tx of USB-TTL goes to Rx (3.3v level) of ESP board

GND is made common.

5v of USB-TTL is connected to Vcc of ESP board.As the ESP board has a built in 3.3v regulator we can connect to 5v safely.

Connect the GPIO0 pin to GND.

IMG_20161107_080700

 

Open the Arduino IDE & select the COM port allotted to the USB-TTL board.

Other settings are done under Tools tab as seen in screenshot below :

Image23

From File —> Examples —> ESP8266 select the BLINK sketch.

As we’ve connected an LED at GPIO4 pin , change the pinMode & digitalWrite pin to 4.

Ensure that GPIO0 is connected to GND & click on UPLOAD button.

It takes a while to compile & then uploading starts.

Image25

Once the Uploading is done the LED connected at pin 4 , starts blinking.

Remember to upload another sketch, you need to ground GPIO0 and push the reset switch. The ESP8266 will be put in UPLOAD mode.

When the upload is done, the sketch will start running. If you reset with GPIO0 still grounded, the sketch will not start running because the ESP8266 will be in PROGRAMMING mode. To exit programming mode, remove the ground from GPIO0.

WATCH THIS VIDEO :

 

 

In the next post we shall see how to use the built in WIFI library in your code.

cooltext753793315   cooltext753790696

This post is a practical demo on controlling an LED from a browser.

Arduino ETHERNET SHIELD is used here. The Browser acts as a CLIENT & the SHIELD acts as a SERVER listening on HTTP PORT 80.

This demo is done on a Local Area Network .This means that the PC from where Browser is operated & the ETHERNET shield both are connected to the same NETWORK. You may have a Router in top of your Network.The Ethernet shield is connected to one of the RJ45 connector of the Router using a STRAIGHT Ethernet cable.The PC from where you start your browser is also connected to the same Router , to another RJ45 connecter or through WIFI , if your Router is WIFI enabled.

Once you connect the RJ45 cable to Ethernet shield, the left LED on RJ45 socket glows Green.This indicates a successful link made to Router.

 

IMG_20161030_153619

 

 

Image 5

Digital pin 2 is used to connect to an LED through a resistor.

Digital pin 13 is occupied by Ethernet shield , so the built in LED on pin13 cannot be used.

When the Ethernet shield is connected to the Router an IP address is allotted by DHCP of the Router.As it is Dynamic & keeps changing on every boot up , we assign the IP using the code :

byte ip[] = { 192, 168, 0, 150 };

Note that , this IP should be in the same range of your Network.

To know the range , Open Network sharing center

Click on your connection & then the DETAILS tab

Here you can see the Gateway IP & IPV4 of your PC.You should assign an IP in the same range

In my case the gateway IP is 192.168.0.1

So I’m assigning the IP of Ethernet shield by changing the last byte of the address , say, 192.168.0.150

Image 1

 

Here is the sketch used in this demo :

————————————————–

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 0, 150 }; // IP address in LAN – need to change according to your Network address
byte gateway[] = { 192, 168, 0, 1 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(80); //server port

String readString;
int ledPin = 2;

void setup(){

    pinMode(ledPin, OUTPUT); //pin selected to control
    // Test LED
    digitalWrite(ledPin, HIGH); // set pin high
    delay(500);
    digitalWrite(ledPin, LOW); // set pin low
   
    //start Ethernet
    Ethernet.begin(mac, ip, gateway, subnet);
    server.begin();
}

void loop(){
    // Create a client connection
    EthernetClient client = server.available();
    if (client) {
        while (client.connected()) {
            if (client.available()) {
                char c = client.read();

                //read char by char HTTP request
                if (readString.length() < 100) {

                    //store characters to string
                    readString += c;
                }

                //if HTTP request has ended– 0x0D is Carriage Return \n ASCII
                if (c == 0x0D) {
                    client.println("HTTP/1.1 200 OK"); //send new page
                    client.println("Content-Type: text/html");
                    client.println();

                    client.println("<HTML>");
                    client.println("<HEAD>");
                    client.println("<TITLE> ARDUINO ETHERNET SHIELD</TITLE>");
                    client.println("</HEAD>");
                    client.println("<BODY>");
                    client.println("<hr>");
                    client.println("<hr>");
                    client.println("<br>");
                    client.println("<H1 style=\"color:green;\">ARDUINO ETHERNET SHIELD — LED ON/OFF FROM WEBPAGE</H1>");
                    client.println("<hr>");
                    client.println("<br>");

                    client.println("<H2><a href=\"/?LEDON\"\">Turn On LED</a><br></H2>");
                    client.println("<H2><a href=\"/?LEDOFF\"\">Turn Off LED</a><br></H2>");

                    client.println("</BODY>");
                    client.println("</HTML>");

                    delay(10);
                    //stopping client
                    client.stop();

                    // control arduino pin
                    if(readString.indexOf("?LEDON") > -1) //checks for LEDON
                    {
                        digitalWrite(ledPin, HIGH); // set pin high
                    }
                    else{
                        if(readString.indexOf("?LEDOFF") > -1) //checks for LEDOFF
                        {
                            digitalWrite(ledPin, LOW); // set pin low
                        }
                    }
                    //clearing string for next read
                    readString="";

                }
            }
        }
    }
}

——————————————————————————

  The Arduino talks to Ethernet shield over SPI Serial Peripheral Interface. So to work with the shield you need to include both the Ethernet & SPI libraries in the top of the sketch.

#include <SPI.h>

#include <Ethernet.h>

 

The next piece of information is the MAC address of the shield , usually expressed as 6 bytes.

If your Shield has the address printed , use that MAC address.Otherwise you can settle for a random 6 bytes , as it is unlikely that another device of same address exists in the same network.

The MAC address is typically included in the Arduino sketch as global array of bytes.

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

The server is assigned on  HTTP port 80

EthernetServer server(80);

PIN 2 is assigned to LED & a string variable readString is assigned to store the request.

Under void SETUP

The method begin() in the Ethernet class attempts to connect to the Network using the details passed into its arguments.

Here we pass an IP address & the Ethernet shield makes a Network connection using a STATIC IP address.

Ethernet.begin(mac, ip, gateway, subnet);

server.begin()

starts listening on the HTTP port 80

To check the IP connection press WIN Logo key +R & then type in CMD

Ping the IP address of the Shield.

If you get back result , then you’re ready to connect the client.

Image 6

On computer Networks the machines or devices play 2 different roles : CLIENT & SERVER.

For e.g a web browser is a CLIENT that connects to other machines to request web pages or files.

The device or machine that serves the information is the SERVER.

SERVERs wait until a CLIENT connects & starts conversation with them.

PORTS allow different types of messages to be received by different pieces of software running on same server.For e.g Server software that accepts connection over FTP will usually run on port 21.WEB server software usually accepts connection over HTTP on port 80. In this demo we use he WEB SERVER.

Now open up the browser on a PC which is in the same network as Shield.

Type in the address 192.168.0.150

The following CLIENT REQUEST & SERVER RESPONSE happens in the background.

Client Request :

When you surf to the IP address of the Arduino server, the web browser (client) will send a request, such as the one shown below, to the server.

GET / HTTP/1.1\r\n

Host: 10.0.0.20\r\n

The information in the request will differ, depending on the browser and operating system that the request is sent from.

The \r\n characters that you see at the end of every line of text in the request are non-visible characters (non-printable characters). \r is the carriage return character and \n is the linefeed character (or newline character).

The last line of the request is simply \r\n without and preceding text. This is the blank line that the Arduino sketch checks for before sending a response to the client web browser.

In other words, the sketch reads every character from the above request and knows when the end of the request has been reached because it finds the blank line.

Server Response :

After receiving the request for a web page from the client, the server first sends a standard HTTP response and then the web page itself.

The response sent from the Arduino is as follows:

HTTP/1.1 200 OK\r\n

Content-Type: text/html\r\n

Connection: close\r\n

\r\n

Again the non-visible characters \r\n are shown in the above response.

The println() function in the the sketch automatically adds the \r\n characters to the end of each line. The empty println() function at the end of the HTTP response simply sends the \r\n with no text in front of it.

The above request and response are part of HTTP

Web Page

After the server has sent the HTTP response, it sends the actual web page which is then displayed in the browser.

The web page consists of text with HTML tags. You do not see the tags in the browser as these tags are interpreted by the browser.

The actual HTML markup tags are shown below.

————————————————-

<html><head>

<title> ARDUINO ETHERNET SHIELD</title>

</head>

<body>

<hr>

<br>

<h1 style="color:green;">ARDUINO ETHERNET SHIELD — LED ON/OFF FROM WEBPAGE</h1>

<hr>

<br>

<h2><a href="/?LEDON" "="">Turn On LED</a><br></h2>

<h2><a href="/?LEDOFF" "="">Turn Off LED</a><br></h2>

</body></html>

—————————————————–

In the Arduino sketch you can see these HTML tags sent using

client.println command

Now the browser displays the WEB PAGE sent as response from the Server.

Click on

Turn On LED   -  to see the LED going ON

Turn Off LED   – to make the LED OFF

indexOf String function is used to search for the string LEDON or LEDOFF.

The indexOf function returns a –1 if it doesn’t find the wanted string.This function is used to make the LED ON or OFF accordingly.

0Image 2

 

Image 3

 

Image 4

 

Instead of LED you can connect a Relay board & then control any home device through the contacts of the Relay.The above setup is the basic to start with Home Automation.

This demo is done on Local Area Network .It can be extended to Internet of Things through Port Forwarding & DDNS set up which is explained in another post.

In the previous post PART 1  we explored the ways to make the local IP address of PC/ESP8266 STATIC.

In this part 2 we shall see how to make your Dynamic Public IP as STATIC using NO-IP account & then Port forward to the server started on port 350 of ESP.

PORT FORWARDING

First let us do the PORT FORWARD  settings.

For this , type in your Router’s Gateway IP in the browser & log in to Router’s Settings.Here my Router’s gateway is 192.168.1.1

The PORT Forwarding is done under VIRTUAL SERVER.

For different Router , you can check out this excellent link which guides settings for almost all types of Routers in the World.

https://portforward.com/router.htm

In my case the VIRTUAL SERVER is under ADVANCED —> NAT

 

image1

Under Virtual Server feed in the WAN & LAN ports as 350.

Under LAN IP feed in the static IP of our ESP8266.Here it is 192.168.1.10 which we made static as described in part 1.

Once the APPLY CHANGES button is clicked , the entry appears under Forwarding Table.

Image 2

 

WINDOWS FIREWALL SETTINGS

 

Next is the Windows firewall settings to allow communication through port 350.

Open Windows Firewall with Advanced Security.

Click on Inbound Rules & then New Rule.

 

Image 3

 

Select Rule Type as PORT.

protocol as TCP.

 

Image 4

Under Action select “Allow the Connection”

& tick mark all under the Profile.

Provide a Name for the Rule & save it.

Image 5

 

START SERVER ON ESP8266

Now open the Putty window where you’ve connected ESP8266 ( refer part 1 for details)

Before starting server , issue the command

AT+CIPMUX=1

Then start the server on port 350 using

AT+CIPSERVER=1,350

Image 111

Now the Server starts listening on PORT 350.

 

Convert Public IP to STATIC

The external world communicates with your ESP server using the Public IP of your Network.This IP is generally DYNAMIC which means it changes on every boot of your Router.

To make it STATIC we shall use a service called NO-IP which converts your public IP to a Domain name & follows the changes.

Visit www.noip.com

Sign up by providing your EMAIL.

Image 6

LOG IN  your NO-IP account.

Under Dynamic DNS click on ADD HOSTNAME.

Image 7

Enter the host name, for e.g , as   testmyiot  & from the dropdown select a domain , say, ddns.net.

Now your new host name is

testmyiot.ddns.net

 

Image 8

Next , click on Device Configuration Assistant.

Image 9

 

Under the dropdown select the host name we created , testmyiot.ddns.net

 

Image 10

Next step is to fill in the Device details.

Device type is SERVER

Device Brand is WEB SERVER

Router make – select your router name .If not found in list then select other

& then enter Router type as Home.

Image 12

On the Next window answer NO

We shall come back to this window shortly after setting the Router for NO-IP.

Image 13

 

On the next window , before clicking YES to log in device, go to the Router settings in browser where you typed in 192.168.1.1

Image 14

 

Click on SERVICE & then DDNS.

Most of the Routers support NO-IP & is listed on the drop down.

Select NO-IP

Image 15

Feed in the Host Name as testmyiot.ddns.net

Provide the email & password you used to create the NO-IP account.

Image 17

Click on ADD to save to DDNS Table of Router.

Now go back to your NO-IP account window.

Click YES to log in device.

Image 18

On next window click on TEST CONNECTION

Image 19

After a short time you should see SUCCESS.

Now you’re done with DDNS settings.You need not go further to Port forward tab, as we’ve already done it.

Image 20

 

Following is the procedure , in case your Router doesn’t support NO-IP .

If you do not see NO-IP under drop down of DDNS settings of Router,

go back to your NO-IP account & click YES to the question “Is there a computer always running on your Network?”.

 

Image 22

 

You’ll be taken to next window to download DUC.

DUC- Dynamic Update Client is a software which runs in the background of your PC to follow your public IP.

Download it & install.

Image 23

Before FINISH ensure to tick mark “Run DUC in the background”

Image 24

Now you’ll be asked to login your NO-IP account again

Image 25

Once you log in, the following windows appear.

Select the host name you created & click save.

Image 26

Now you can see all TICK marks in the DUC window.

DUC runs in the background & follows your public IP to the domain name you created.

Image 28

 

You can test the access to ESP server now from a distant PC.

From anywhere in the world , make open a PUTTY window.

Select RAW & feed in the host name testmyiot.ddns.net & port as 350.

Image 29

You get CONNECTED to the ESP server

 

Watch this demo video :

 

 

 

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This post is all about converting your device address in Network to STATIC & establish PORT FORWARDING.

For IOT projects it is easy to test in local setup using  the LAN IP starting with 192.x.x.x .But from outside world this IP cannot be reached.Here I will walk you through the steps to contact the local IP from outside world.This procedure is a major step needed in IOT projects  , without which external control is not possible.

Following is the setup of my Network. A ROUTER is on the top of the network for which the Internet Service Provider is Airtel . The Router is WIFI enabled so that I can connect multiple devices wirelessly.

Total 3 devices are connected to the Router as shown below.

 

setup_ok

 

On switching on the power , the Router (DHCP enabled) assigns local IP addresses to all the devices connected.The IP address assigned is DYNAMIC which means , it changes every time I switch on the Router.

There are two types of IP addresses: STATIC & DYNAMIC

STATIC addresses are just that – unchanging

Dynamic IP addresses are assigned on-the-fly & keeps on changing by every reboot.

Because most home users tend to turn their computers off, even broadband connections, such as DSL and cable, continue to use dynamic addresses. If your computer is off, you don’t need an IP address so someone else might get to use it.

Each time you connect to the internet, your ISP assigns you an IP address to use. This IP address is the Public IP which others use to communicate to your PC.This IP address is DYNAMIC which changes every time you newly connect to web.

The next time you connect, you might get a different address. If you’re only connecting out to the internet, that’s all you need.

If you expect people to connect in, say you want to run a web server that you want people to be able to find and visit, you’ll most likely need a STATIC IP address. A static IP is assigned by your ISP at an extra cost which is unnecessary for a home network.

In this post I shall explain the ways of changing the LOCAL IP address  as well as the PUBLIC IP address to STATTIC.Suppose you run a web server on your ESP or Raspberry PI & wish to connect from external world.It will work only for the first time , as you use Dynamic IP to communicate.

Next time you power up , the IP address might have changed.So using a STATIC IP is a must .

 

SETTING the Local IP of PC / Laptop to STATIC :

 

In my network the PC assigned a Dynamic IP of  192.168.1.10

Run –> CMD –> ipconfig /all       reveals the  address details as seen below :

ipconfig

 

Here you can see the Default Gateway is 192.168.1.1 which is the IP of the Router .To port forward settings we need to use this IP on a browser to enter the settings , which we will see later in the post.

Local IP assigned to the PC is the IPV4 address 192.168.1.10

Let us change this to STATIC now.

Open the CONTROL PANEL –> NETWORK and Internet  –> Network and Sharing center

Click on “Change adapter settings”

Image 10

 

Right Click on the Network connection & select Properties

Image 11

 

Select the Internet Protocol Version 4 & double click on it.

Image 12

Now you see the following screen where selection is done by default to obtain IP automatically.

Change this selection o “USE the following IP address “ & enter the IP as 192.168.1.150

The first three bytes must match that of the default gateway address which is 192.168.1.1

The last byte can be assigned at your will , within the IP range allowed by the router.

Here I change the IP to 192.168.1.150.  Note that only the last byte I’ve changed.

Subnet mask & Default gateway are entered as seen in the ipconfig /all window above.

 

Image 13

 

DNS server address also changed as seen in the screen shot below

Image 14

Image 15

Reboot your PC to see the changes effective.

Now the IP address of my PC will be 192.168.1.150 & remains STATIC even after reboot.

The above task can also be done automatically by a trial software :

PF_1

 

You can download the trial version here :

http://portforward.com/store/download-instructions/pfconfig/

The trial version allows all other tools except port forwarding.Open the tool & click on STATIC IP Address & follow the guidelines to fix your PC’s IP as STATIC.

 

STATIC IP for other devices ESP & Raspberry PI:

 

For making the Raspberry Pi’s Local IP to STATIC you can follow this blog :

https://www.modmypi.com/blog/tutorial-how-to-give-your-raspberry-pi-a-static-ip-address

 

Regarding the IP of ESP8266 we need not change anything.Once the STATION IP is assigned to ESP8266 , the module remembers the Access Point it has connected & the STA IP assigned .

or issue the command

AT+CIPSTA=”192.168.1.5”

Image 16

The ESP module remembers the Access Point it has joined with & the IP till you quit the AP.

But on Reset it seems to get changed.

The only way to assign STATIC IP to ESP module is through the Router settings.

In your browser type in the IP address of your Gateway , here it is 192.168.1.1

Under LAN setup look out for DHCP settings.

In latest Routers you see a setting called DHCP RESERVATIONS.

In the IP Address field, type the IP address to assign to the computer or server.
Choose an IP address from the router’s LAN subnet, such as 192.168.1.x.

Type the MAC address of the ESP MODULE server.
As the ESP has already joined the AP, it  is already on your network, you can copy its MAC address from the Attached Devices screen and paste it here.

Here I will show an example of setting the Static IP in DHCP Reservation under BEETEL Router

In almost all the Routers the settings are the same.Just look out for the wordings Open-mouthed smileHCP RESERVATION” or “DHCP STATIC “ under the LAN setup.

 

dhcp1

 

Under DHCP STATIC tab , enter the IP address you want to fix for the ESP module

dhcp2

 

Feed in the MAC ADDRESS of the ESP device.

dhcp3

You can learn the MAC address from the AT command AT+CIFSR of ESP module.

dhcp4

The MAC address to be entered without any special character like colon.Please check out your Router settings for entering the MAC address (generally given near the MAC address box , how to feed in the address).

dhcp5

Click on ADD to save the settings

dhcp6

Now RESET or power back the ESP module.

The IP address will be the same for ever.The Router will always assign the IP you’ve set for the ESP module.

dhcp7

 

In a  D-Link router, it is under  the setup.Go to Setup / Network settings / DHCP reservation. You can then ask the router to give a given MAC address a fixed IP address.
Alternatively, the ESP can request a certain IP address from the router which we’ve seen in the example of Beetel Router above.

Now that the STATIC IP is assigned, let us see the methods of PORT FORWARDING & converting your public IP to STATIC using NO-IP account in PART 2.

 

In the previous post part-1 I explained the initial setup of starting a Server on PC on a port , setting the Windows firewall to allow the port for external communication , PORT FORWARDING set up in the Router config, etc..

https://alselectro.wordpress.com/2016/09/25/gsm-connecting-to-a-server-on-a-port-by-tcpip-part-1/

In this part 2 I’ll show a practical demo of sending Temperature data to the Server.

As given in part 1 , start a server on distant PC on port 350 & do the port forwarding settings in Router config as explained.

A LM35 sensor is connected to pin A0 of Arduino & a GSM SIM900A is connected to pins 7 , 8 , Gnd of Arduino. As Soft Serial library is used in the code , pins 7 & 8 are declared as soft Rx & Tx.

The Rx pin goes to Tx of GSM , Tx connected to Rx of GSM , GND is made common.An external power source of 12v 1A is used for the GSM.

Download the Arduino code HERE

————————————-

#include <SoftwareSerial.h>
SoftwareSerial myGsm(7,8);
float temp;
int tempPin = 0;
void setup()
{
myGsm.begin(9600);
Serial.begin(9600);
delay(500);

myGsm.println(“AT+CIPSHUT”);
delay(1000);
printSerialData();

myGsm.println(“AT+CIPMUX=0”);
delay(2000);
printSerialData();

myGsm.println(“AT+CGATT=1”);
delay(1000);
printSerialData();

myGsm.println(“AT+CSTT=\”bsnlnet\”,\”\”,\”\””);//setting the APN,username & password
delay(5000);
printSerialData();

myGsm.println();
myGsm.println(“AT+CIICR”);
delay(6000);
printSerialData();

myGsm.println(“AT+CIFSR”); //get IP address
delay(2000);
printSerialData();

myGsm.println(“AT+CIPSTART=\”TCP\”,\”122.178.80.228\”,\”350\””);
delay(5000);
printSerialData();
delay(5000);

myGsm.println(“AT+CIPSEND”);
delay(2000);
printSerialData();

sendtemp();
delay(3000);
myGsm.println(“AT+CIPCLOSE”);
printSerialData();

myGsm.println(“AT+CIPSHUT”);
delay(1000);
printSerialData();
}

void loop()
{
}

void printSerialData()
{
while(myGsm.available()!=0)
Serial.write(myGsm.read());
}

 

void sendtemp()
{
temp = analogRead(tempPin);
temp = temp * 0.48828125;
Serial.print(“TEMPERATURE = “);
Serial.print(temp);
Serial.print(“*C”);
Serial.println();
delay(5000);
myGsm.println(temp);
delay(3000);
printSerialData();
myGsm.write(0x1A);
delay(3000);
printSerialData();

}

———————————————-

The Analog pin A0 is assigned as tempPin to read the LM 35 sensor data.

Initially any previous IP connection is SHUT  using the command

AT+CIPSHUT

This is essential to start a fresh TCP/IP comnnection.

Single IP connection mode is set by

AT+CIPMUX=0

GPRS is attached using

AT+CGATT=1

Task is started with the command

AT+CSTT=”APN”,”USER NAME”,”PASSWORD”

The Access Point Name of the mobile service provider can be known  by placing the SIM on your Android mobile. It’s shown under

Settings  –> More..  –>  Cellular Networks –> Access Point Names

In my case the APN is bsnlnet , user name & password are empty

AT+CSTT=”bsnlnet”,””,””

 

Then we bring up the Wireless connection with GPRS using

AT+CIICR

This takes a little moment , so a delay of 6 secs is a must in the code.

The IP address assigned by GPRS is obtained by

AT+CIFSR

Now we start up TCP connection with Server IP address & Port number of distant server

AT+CIPSTART=”TCP”,”122.178.80.228″,”350”

Once the connection is established , we send data using

AT+CIPSEND

A CTRL+Z is required to send data which is executed using hex 1A

 

Upload the code to Arduino & open the Serial monitor to watch the AT commands executed

tcp_list

 

Following is the screen shot at the Server side.

 

Image 3

 

 

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This tutorial is of 2 parts.

First part explains the following :

–Starting a Server on your PC  & start listening on a port (say 350) . For this we use SOCKET TEST or HERCULES software

— Once the port is listening , we test communication locally using PuTty

— Windows Firewall setting has to be done for a NEW INBOUND RULE allowing port 350 for communication.

— For connecting to this port from external world , PORT FORWARDING to be done in Router’s Virtual Server setting so that any contact to the public IP is routed to the PORT 350 .

 

Second part is practical demo using GSM SIM900 or ESP8266 with Arduino.

 

The following picture shows my simple home network connections.A BINATONE make Router is used to connect to the Internet provider Airtel Broadband.The IP address of the Router is

192.168.1.1

which is the Gateway IP address used to access the settings on Router.My Laptop is connected over WIFI to this Router.The Router assigns a local IP address to my PC which is

192.168.1.150

Apart from these, the Internet Provider assigns a Public IP to my Network which is

122.178.80.228

This is the IP by which external world can contact my network.

Note that all these IP addresses are DYNAMIC & changes every time I power up the Router.

In another post I’ll explain how to make these IP addresses STATIC , so that the IP remain the same always.

set1

 

All the Network Tools I’ve used for this demo can be downloaded HERE.

Let us start  a server on port 350 using the SOCKET TEST tool.

This tool allows us to start a server easily.Click on the SERVER Tab & then feed in the port number where you want to listen.

Click on START LISTENING.

soc1

Now the server is up & running.It starts listening on port 350.

Remember to avoid the standard ports like 80 ( http) , 21 (FTP), 23 (TELNET), 22 (SSH) ,etc which are well known ports ,pre assigned for the particular protocol.

The dynamic range of port number you can assign goes up to 65535 or 2^16-1 (16 bits).

The IP address of the router can be known from the command window

RUN –> CMD –> ipconfig

The Default Gateway IP is the address of the Router.

RUN1

 

LOCAL TESTING TOOLS (optional)

 

Once the port is assigned for the server , you can use the ADVANCED PORT SCANNER tool to verify the port on the particular IP.

In the screen shot below you can see that the port number 350 is discovered as a TCP Server port on my PC whose local IP is 192.168.1.150

 

port_scanner

While the port scanner is scanning , you get messages on your SOCKET TEST window.

Here you can see the Port scanner software connecting to the port & then disconnecting after scanning.

port_message

 

Alternatively you can use a PUTTY serial port tool to test local communication.

Select the connection type as RAW & provide the host IP which is 192.168.1.150 & thtn the port number 350

putty1

Click on open , to see the New client connection on the Socket test window.

putty4

 

Now you can test two way communication between  socket test (server) & putty ( client).

putty2

 

WINDOWS FIREWALL SETTINGS

 

The Windows Firewall settings has to be done to allow the port 350 to listen from outside.

Open the Windows Firewall & Advanced Security window.

Click on Inbound Rules & then New Rule.

windows1

 

Select the Rule Type as PORT & in the next screen select protocol as TCP.

Under Specified local ports feed the port number as 350

windows2

 

Under Action window select Allow the Connection

Next window is Profile window , here tick mark all – Domain,Public & Private.

Provide a name to the Rule & save it.

Now your PORT 350 is allowed to listen by the Windows Firewall.

windows3

 

PORT FORWARDING

This step is final where you redirect the incoming request to the port number of local IP where the server is started.

Here my local PC’s IP is 192.168.1.150   &  server is started on port 350.

Anyone from external world connecting to my public IP has to be directed to the port 350 on local IP 192.168.1.150.

This is called PORT FORWARDING , which is very widely used in CCTV Remote viewing & in Gaming.

The setting has to be done in your Router.

Type in the Gateway IP of your Router , here it is 192.168.1.1 , on your browser & provide the user name & password.

Here is an excellent website showing all screen shots of almost all Routers in the world

https://portforward.com/router.htm

 

Mine is BINATONE Router.

You’ve to search for something called VIRTUAL SERVER on the router setting.

 

ROUTER1

 

For my Router it’s hidden under ADVANCED SETUP –> NAT –> VIRTUAL SERVER

For more details you can visit the above portforward link

Create a new Virtual server listing by entering the

— Port number , which is 350 .Enter same number at all fields like start & stop.

— Local IP address , here you provide the IP where server is started , 192.168.1.150

— save the listing

router3

 

Once saved , the port number 350 is open to outside world.

Online port open test tools are available

www.canyouseeme.org

www.yougetsignal.com

 

Once you open the link , your public IP will be automatically shown.

Fill in the PORT number to be checked & click on CHECK button.

If you see SUCCESS , then you’re done with PORT FORWARDING

 

canyou1

 

port_open

 

Following is the list of AT commands used by the GSM SIM900A to contact the server.

This is for part 2 of the post.PART 2 LINK HERE

gsm1

gsm2

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