NetSensor step 3: The browser talks to the Arduino

Finding your PC's ip address
To get your browser to talk to the Arduino its important that both share the same ip subnet.
So the next step is to find your computers ip address. The following links should help you with it.

 Windows, Mac users:

Linux users:

Type the following command on the command prompt

> ifconfig eth0

eth0      Link encap:Ethernet  HWaddr bc:ae:c5:49:b1:ee 
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::beae:c5ff:fe49:b1ee/64 Scope:Link

What to do once you got your ip ?
Once you have your ip, lets say its The next step is to pick an ip address in the same subnet for the Arduino so that the PC can talk to the Arduino.
For simplicity sake, just increment the last digits of the ip address by 1 and use that ip address for the Arduino.
In the example case, if your ip as, then we would use for the Arduino.

NOTE: This should work in most cases, only case where this wont is when there is another host on the network with the same ip as the arduino. If that happens pick another ip say x.x.x.23

Now you have the ip address for the Arduino, how do you program it in ?

In file DHT11_JSON.ino you will find the following snippet of code which has a comment "Enter your chosen IP here", Go ahead and write the derived Arduino IP address there.

IPAddress ip(192,168,20,8); // <<<< Enter your chosen IP here

After the above changes compile, upload the code to the Arduino.

Connecting the ethernet port of the arduino to the network, there are 2 ways to go about it.

  • Connect Arduino to PC's ethernet port

  • Connect to the LAN port of your wireless router ( preferred option )


Test if the PC can talk to the Arduino 
The simplest way to test the connection is to ping the arduino
This can be done using the following command in the command prompt :

> ping

If you get a response like this, it means all is well and you can proceed to the next phase:

PING ( 56(84) bytes of data.
64 bytes from icmp_req=1 ttl=128 time=0.519 ms
64 bytes from icmp_req=4 ttl=128 time=0.098 ms

--- ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 2999ms
rtt min/avg/max/mdev = 0.083/0.201/0.519/0.183 ms

NetSensor Up and Running....
Now is the final moment to see all the pieces come together and you get to see your kit live on the intenet.
To see the kit live, click the following link ( preferably in firefox browser for best results),
then feed in the Arduino's ip address:

NetSensor Live

Playing with the NetSensor
  •  Click the bump sensor and see the alarms go off
  •  Breathe into the DHT sensor and see the effect on the humidity and temperature readings

More things to do..

Can you interface this motion sensor into this kit ?

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