Communication Mediums: Arduino WiFi, RN-42 Bluetooth, Netduino Ethernet

This blog was written back in 2012, hope you enjoy it.

Hello, I have gotten my hands on a couple of communication devices which could be used for android and Arduino/ Netduino communication, first RN-42 SMD bought from robotics.pk — link, Arduino WiFi Shield also bought from robotics.pk — link and third Netduino itself which comes with Ethernet shield built-in, and Netduino is given to me by my teacher for educational purposes only, sad cant keep it.

Anyways let us start off with, RN-42 SMD is fairly cheap compared to others available for sale on spark fun and is very easy to use you just need 4 connections VCC(3.3v), GND, RX and TX and you are done and by default, RN-42 runs on 115200 baud rate, I found this to be very cheap and easy to use although for making connections on the SMD, could be stressing, you would need small and steady hands, after making connections and connecting it to my Arduino Mega 2560, I used my serial Bluetooth android app and data transfer was done perfectly and fast, and the range was acceptable about 50 to 60 feet. it is a perfect fit for the short-range, battery-powered application.

The second device is WiFi Shield, which lets Arduino board connect to the internet using the 802.11 wireless specifications and comes with a micro-SD card socket for saving of HTML pages and data logging, we could either use the WiFi Shield as Server or Client and in my case I use it as a server, although Arduino can't process anything above HTML and JavaScript we can do with these all so well, with WiFi Shield, we use Get and Post methods — (which I will explain in next post how?) to send and receive data from Arduino, from then on its same as serial monitor or Bluetooth. So from my android I send a request on the IP which is assigned to WiFi Shield through DHCP, the request could be Get or Post and Arduino executes that request.

Arduino and WiFi Shield: Controlling my room lights from Kazi Murtaza on Vimeo.

The third device which is Netduino in-built Ethernet Shield, I have not gotten around to configure it yet, but will do it next. I feel the results will be the same as Arduino WiFi Shield.

So in end I realized one thing, WiFi Shield is a bit buggy, sometimes requests in the buffer of Arduino don’t really execute and if they do its 4–5 sec delay, I guess it takes time to process the request and it is fairly new so needs a firmware update, so WiFi shield is not recommended for on second execution for example like WiFi controlled car, for such projects Bluetooth should be preferred, and for projects such as Home Automation and such WiFi is ideal.

Originally published at http://kazimurtaza.com.